760 - Contribution Of Fluoride In Water And Food To The Prevalence Of Fluorosis In Areas Of Tamil Nadu In South India.
Fluoride contents of water and food, collected from the subjects of five selected areas of Tamil Nadu in South India, were determined. Surveys were conducted to ascertain dental fluorosis prevalences among children of the areas, and dental and skeletal fluorosis prevalences in the adult populations. Dean''s ''Community Fluorosis Index'' (CFI) for dental fluorosis was calculated, from the children''s survey, and was found to be correlated with the prevalence and severity of fluorosis in the areas. A direct correlation was also confirmed between the mean fluoride level in drinking water and the percentage incidence of dental fluorosis. The dominant role of fluoride from drinking water, when compared with that from food, was established.
Dans l'Inde du sud, la fluorose a une prévalence importante, liée à la teneur élevée en fluor de l'eau, beaucoup plus importante que l'apport de fluor par les éléments. 761 - Fluorosis Induced By Drinking Brick Tea.
Fluorosis in China has been known to be induced by two main causes. One is water-dependent fluorosis caused by a long-time consumption of high- fluoride (F) containing water. The other is called ''coal- burning type fluorosis'', caused by inhalation of air polluted by coal smoke and/or ingestion of food exposed to coal smoke. We conducted a study on a group of Tibetan residents who regularly consumed brick tea containing high F levels. Many of the adults and children were found to be afflicted by fluorosis. Our results led us to present a third type of fluorosis in China called ''brick tea type fluorosis''.
C'est le même thème et les mêmes auteurs que la fiche numéro 4045, les conclusions sont identiques. 762 - Bioavailability Of Fluoride Administered As Sodium Fluoride Or Sodium Monofluorophosphate To Human Volunteers.
This paper reports a reassessment of the bioavailability of fluoride from monofluorophosphate (MFP, CAS 10163-15-2). It was prompted by recent work from this laboratory reporting that, following an oral dose of MFP, a fraction of the drug appears in plasma bound to globulins forming a previously undetected compartment of non-diffusible fluoride. The presence of protein-bound MFP in plasma after the intake of this drug hinders its straightforward comparison with NaF (CAS 7681-49-4). After an oral of NaF, all plasma fluoride is diffusible. After intake of MFP, on the other hand, plasma contains diffusible fluoride and protein-bound fluoride during the 6-8 h following intake. The area under the curve of total plasma fluoride for MFP (1540 +/- 117 mumol.min/l) doubles that of NaF (811 +/- 52 mumol.min/l p < 0.001). On this basis, in agreement with findings previously reported for the rat, it is concluded that the bioavailability of fluoride for MFP doubles that of NaF.
Ce travail, chez l'homme, confirme que la disponibilité biologique est deux fois plus importante avec la prise orale de monophosphates de fluor que celle du simple fluorure de sodium, comme cela a été démontré chez le rat.763 - Dental Status And Fluoride Consumption Among Five-year-old Schoolchildren In Strasbourg, France.
An epidemiological survey of the caries prevalence in 1743 five-year- old children was conducted in Strasbourg in 1991 and compared with a similar study performed in 1973 (Jung et al, 1975). In 1991, 44.2 percent of the children were caries-free and 3 percent of the sample had experienced extractions of carious primary molars. The average values of the dfs and dft indices were 2.93 and 6.10, respectively, with a caries reduction of 35 percent when compared to the 1973 data. The majority of children (87.96 percent) used fluoridated dentifrices and 49.5 percent of them benefited from at least another combined fluoride supplementation. The latter showed lower caries indices than the unsupplemented ones. The average plaque index and gingival index values were 0.62 and 0.1, respectively: 46.4 percent of the children had a plaque index of 0.
Une étude faite par le groupe strasbourgeois, comparant une population d'enfants de 5 ans en 1973 et en 1991, d'où il apparaît une réduction considérable des caries depuis que la supplémentation en fluor a été mise en pratique.764 - Selenium As A Risk Factor For Cardiovascular Diseases.
Selenium is a powerful antioxidant regulating the activity of the glutathione peroxidase enzymes, which catalyse the detoxification of hydrogen peroxide and organic hydroperoxides. Selenium deficiency has been implicated in the aetiopathogeny of Keshan disease, an endemic cardiomyopathy observed in China, and in other cases of congestive cardiomyopathy in subjects on artificial nutrition. However, the evidence from case-control and prospective studies for an association between low selenium status and cardiovascular diseases remains controversial. Mechanisms whereby selenium protects against such diseases include increased resistance of low-density lipoproteins against oxidative modification, modulation of prostaglandin synthesis and platelet aggregation, and protection against toxic heavy metals. The therapeutic benefit of selenium administration in the prevention and treatment of cardiovascular diseases still remains insufficiently documented.
Le sélénium est un puissant agent antioxydant, régulant l'activité de la glutation-peroxydase, enzyme qui catalyse la détoxication du peroxyde d'hydrogène et des hydroperoxydes organiques. Un déficit en sélénium a été incriminé à l'origine de la maladie de Keshan, cardiomyopathie endémique observée en Chine, et également de cas de cardiomyopathie congestive chez des sujets soumis à une nutrition parentérale. Toutefois, les études cas-témoins et les études prospectives n'ont pas fourni de preuve indiscutable d'une association entre déficit en sélénium et maladies cardiovasculaires dans la population générale. La protection apportée par le sélénium à l'égard de ces maladies fait intervenir plusieurs mécanismes : augmentation de la résistance des lipoprotéines de basse densité à l'oxydation, modulation de la synthèse des prostaglandines et de l'agrégation plaquettaire, et protection contre les métaux lourds. Cependant, l'effet bénéfique d'une supplémentation en sélénium dans la prévention et le traitement des maladies cardiovasculaires reste encore insuffisamment démontré.765 - The Effects Of Exercise On Iron Status And Aerobic Capacity In Moderately Exercising Adult Women.
The purpose of this study was to examine the effects of a 10-week moderate exercise on iron status and aerobic capacity of adult women. Seventeen women, 56- to 67-years, served either as controls (no exercise, n = 9) or participated in a supervised exercise program (n = 8). Women in the exercise group cycled on an ergometer three days per week, for 40 minutes at 70 to 75% maximal heart rate for 10 weeks. Pre- and post- (weeks 0 and 11) submaximal treadmill stress tests were obtained. Aerobic capacity was evaluated by heart rate per grade, maximum oxygen capacity, and time to reach 70% maximum heart rate. The results indicated that average heart rate per grade decreased and time to reach 70% max heart rate increased in the exercise group (p < .05) after 10 weeks of moderate exercise training. Iron status as determined by serum ferritin, transferrin saturation, serum iron, total iron binding capacity, hemoglobin and hematocrit was normal and comparable between both groups. Hemoglobin increased (p < .05) after 10 weeks of supervised moderate exercise. The results suggest that 10 weeks of moderate exercise enhances aerobic capacity of older women but does not compromise iron status.
Ce travail a eu pour but de mettre en évidence l'absence d'impact péjoratif sur le bilan ferrique de l'organisme chez des femmes âgées (56-67 ans) soumises à un protocole d'entraînement de 10 semaines, qui a amélioré significativement leurs aptitudes aérobie.766 - Magnesium Status And Risk Of Coronary Artery Disease In Rural And Urban Populations With Variable Magnesium Consumption.
This survey was conducted to determine the association between amount of magnesium intake and prevalence of coronary artery disease (CAD) and coronary risk factors in north India. There were 3575 subjects aged 25-64 years including 1769 rural (894 men, 875 women) and 1806 urban (904 men, 902 women) subjects. The survey methods were questionnaires for 7-day food intake record, physical examination and electrocardiography using World Health Organization criteria. The overall prevalence of CAD was three-fold greater in urban compared to rural subjects (9.0 vs 3.3 per cent, p < 0.001). The prevalence of CAD was significantly higher among subjects consuming lower dietary magnesium. Lower magnesium status was inversely associated with risk of CAD in both rural and urban subjects in both sexes. Among subjects with low magnesium status, there was a higher prevalence of hypertension, hypercholesterolemia and diabetes mellitus showing a significant increasing trend with decrease in magnesium status. Multivariate logistic regression analysis after pooling of data from rural and urban subjects and after adjustment of age showed that magnesium intake had an inverse association with prevalence of CAD. Serum magnesium (odds ratio: men 1.14, women 1.05), dietary magnesium (men 1.21, women 1.12), serum cholesterol (men 1.15, women 1.15), blood pressure (1.26 men, women 1.21), diabetes mellitus (men 1.20, women 1.18) in both sexes and smoking in men (1.05) were significant risk factors of CAD. Lower consumption of dietary magnesium and low serum Mg level in north India have a higher prevalence of CAD and of the coronary risk factors hypertension, hypercholesterolemia and diabetes mellitus. It is possible that increased intake of magnesium to about 500 mg/day may be of benefit in the prevention of CAD.
Un faible apport de Mg dans l'alimentation et une hypomagnésémie en Inde du Nord sont corrélés avec une plus forte prévalence de coronaropathies et de facteurs de risques coronaires : hypertension, hypercholestérolémie et diabète sucré. Il est possible qu'un apport accru de Mg aux environs de 500 mg/jour puisse être bénéfique dans la prévention des coronaropathies.767 - The Effect Of Water Fluoridation On The Bone Mineral Density Of Young Women.
INTRODUCTION:
Osteogenic effects of therapeutic fluoride have been reported/ however, the impact of exposure to low level water fluoridation on bone density is not clear. We investigated the effect of long-term exposure to fluoridated water from growth to young adulthood on bone mineral density (BMD).
METHOD:
BMD was measured in 24 healthy women from Regina (fluoride 0.1 mg/L) and 33 from Saskatoon (fluoride 1.0 mg/L), with no differences between groups for height, weight, lifestyle or dietary factors.
RESULTS:
Saskatoon women had significantly higher mean BMD at total anterior-posterior lumbar spine (APS) and estimated volumetric 1.3 (VLS), with no difference at total body (TB) or proximal femur (PF).
CONCLUSIONS:
Exposure to water fluoridation during the growing years may have a positive impact on axial spine bone density in young women.
Etude canadienne sur l'effet du fluor sur l'ostéogenèse (densité de l'os minéral) chez les jeunes femmes qui sont exposées à une eau fluorée, mais qui a un impact positif sur la densité osseuse de l'axe vertébral. Ceci est le résultat de l'impact durant la période de croissance de l'apport en fluor de l'eau chez ces jeunes femmes pendant l'enfance.768 - Food Habits Among 13-year-old Norwegian Adolescents.
The aim of this study was to describe dietary habits among 13-year- old Norwegian adolescents. Based on a random sample of public schools, a representative sample of 1705 pupils completed a self- administered quantitative food frequency questionnaire (response rate 86%). Nearly 30% of the total food energy was supplied by fat and 12.5% by sugar. The boys had a higher energy intake from fat than girls. The average daily intake of micro nutrients exceeded the recommendations, with the exception of vitamin D and iron among girls. In general, the nutrient density of the boys'' diet was significantly lower than for the girls''. Girls consumed more healthy foods than boys, furthermore girls reported that they were more conscious about their weight. Compared with 18-year-old Norwegian adolescents the 13-year- old pupils had lower energy intake from fat and alcohol and higher energy intake from sugar. Furthermore, the younger pupils skipped breakfast less often than the older ones, and reported that they were more physically active and smoked less than the older pupils. The results suggests that a large part of the adolescent pupils have a relatively healthy diet. However, subgroups of pupils may be at risk of consuming a diet with marginal amounts of several nutrients (vitamin D and iron among girls), and other subgroups have a diet high in fat and sugar.
Enquête de consommation de divers nutriments par auto-questionnaire de fréquence sur un échantillon représentatif de 1705 enfants de 13 ans en Norvège. On Trouve que, à part pour la vitamine D et le fer chez les filles, la consommation des autres micronutriments est suffisante par rapport aux besoins.769 - Caries Progression In 12- To 16-year-old Schoolchildren In Fluoridated And Fluoride-deficient Areas In Brazil.
Water fluoridation may reduce the rate of caries initiation, but relatively little is known of its effect on rates of caries progression through the enamel and the dentin.
OBJECTIVE:
This longitudinal study was designed to compare rates of caries progression in fluoridated and fluoride-deficient areas.
METHOD:
Approximal caries progression was evaluated on two standardized sets of bitewing radiographs taken at a 12-month interval of 290 12- to 16-year-old Brazilian schoolchildren. Pitts'' scoring system was used to measure caries progression on conventional bitewing images. Caries progression data on the occlusal, free-smooth, and approximal surfaces of the anterior teeth were collected via clinical visual examinations.
RESULTS:
The mean rate of approximal caries progression in school-children living in fluoridated areas (0.54) was found to be 62% lower than that in children from fluoride-deficient areas (1.41). When progression rates were adjusted for the initial number of decayed surfaces per subject, differences were statistically significant for lesions located at the inner half of the enamel at baseline (11% in the fluoridated areas vs. 16.5% in the fluoride- deficient areas). Multivariate logistic regression analysis revealed that residence in a fluoride-deficient area remained a significant risk factor for caries progression after controlling for caries prevalence (D1FS), number of cavitated carious lesions, whether tooth type was molar or premolar, and toothbrushing frequency.
CONCLUSION:
These results suggest that water fluoridation reduces the rates of caries progression through the enamel and dentin, but the effect was more pronounced for lesions in the inner enamel than for those in the dentin.
Le rôle de la fluoration de l'eau est bien connu pour la prévention de la carie. Il est moins bien connu sur la progression de la carie à travers l'émail et vers la dentine. Une étude comparative sur une population de 12 à 16 ans, en zone fluorée et en zone non fluorée, donne un résultat positif : l'apport de fluor réduit le taux de propagation de la carie à l'émail et à la dentine. Cet effet est plus net pour les lésions internes de l'émail que pour celles de la dentine.770 - Lipoprotein Oxidation, Antioxidants And Cardiovascular Risk: Epidemiologic.
This review summarizes the scientific evidence for a possible role of antioxidants in the prevention of coronary heart disease (CHD). Dietary antioxidants include vitamin E, vitamin C and beta-carotene, whereas selenium is an integral part of the antioxidant enzyme glutathione peroxidase. Experimental studies suggest that the oxidation of low-density lipoproteins (LDL) in the vessel wall plays an important role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by antioxidant supplementation, at least in vitro. Epidemiological studies have not demonstrated unequivocally that a high intake of antioxidants leads to a decreased risk of CHD. Studies on dietary intake and serum levels of antioxidants do point in the direction of a preventive effect of antioxidants, whereas the results of intervention studies are less conclusive. Beta-carotene supplementation is not associated with any decrease in CHD/ high doses of vitamin E may be beneficial, but results from large trials are to be awaited. General preventive measures based on antioxidant supplementation are not yet justifiable.
Les auteurs passent en revue les données connues sur le rôle des antioxydants dans la prévention de l'athérome coronarien. Les antioxydants d'origine nutritionnelle comprennent la vitamine E, la vitamine C et le bêta-carotène, et le sélénium qui est part intégrante de la glutathion-peroxydase, enzyme antioxydante. L'oxydation des lipoprotéines de basse densité (LDL) dans le développement des lésions athéromateuses et la résistance à oxydation des LDL est augmentée par les oxydants, du moins in vitro. Toutefois, les études épidémiologiques n'ont pas montré de manière indiscutable qu'une supplémentation en antioxydants réduit le risque d'athérome coronarien. Tandis que les études observationnelles suggèrent un effet protecteur des antioxydants, les résultats des études interventionnelles sont beaucoup moins concluants. Il apparaît donc encore prématuré de proposer des mesures préventives générales fondées sur un supplémentation en antioxydants.771 - Available Iron And Zinc In Major Lean Meat Cuts And Their Contribution To The Recommended Trace Element Supply In Switzerland.
The objective of the present study was to analyze iron and zinc in major lean meat cuts in order to estimate the contribution of the average lean meat consumption in Switzerland (1995) for these trace elements. Iron, heme iron and zinc contents were analyzed in following muscles: pork (longissimus dorsi muscle and shoulder), beef (longissimus dorsi muscle and shoulder), veal (longissimus dorsi muscle) and chicken (breast and thigh). Beef and pork shoulder were the best sources of iron, heme iron and zinc. Pork and veal longissimus dorsi muscle and chicken were relatively poor in these trace elements. With an average daily lean meat consumption of 105 g, iron and zinc intake were about 1.1 mg/d and 3.8 mg/d, respectively. Recommendations for daily iron intake were met to 11% (men) and 7% (women) and for zinc to 25% (men) and 32% (women). Applying a modified Monsen model, the requirements for absorbed iron were met in the range of 10-30% and 7-20% for men and women, respectively. Taking into account a zinc absorption rate from meat of about 20-36%, the daily requirements for absorbed zinc were covered to 32-56%
IN CONCLUSION:
the average amount of lean meat as consumed in Switzerland was high enough to be an important source of available iron and zinc, particularly for people with low iron and zinc status.
Analyse de la teneur en Zn et Fe de morceaux de viandes maigres. Les épaules de bœuf et de porc sont les meilleures sources de Fe et de Zn. Le poulet, la longe de porc et de veau ont des teneurs faibles en ces éléments. En prenant en considération la consommation journalière de viande en Suisse, les auteurs estiment à 11% (hommes) et 7 %(femmes) la contrution du Fe aux apports recommandés et à 25% (hommes) et 32% (femmes)celle du Zn. Si l'on tient compte du taux d'absorption du Zn des viandes (20-36%), les apports en Zn couvriraient 32-56% des besoins. En conclusion, la viande est une source importante de Zn et de Fe pour la population Suisse.772 - Prenatal Fluoride For Growth And Development: Part X.
Examinations of prenatal fluoride supplemented (PNF) teeth in an animal model and in a five-month human fetus find these teeth to be more developed than the non-supplemented controls. The fact that PNF allows teeth to develop to their full potential suggests that PNF could be an essential nutrient for the entire human and this could be demonstrated most easily during rapid fetal growth. A review of the recent literature, including trials by NIH and The World Health Organization, provide evidence that fluoride (F) does allow the fetus to grow and develop to its full potential. The authors conclude that PNF must be supplied in at least a 2 mg/day pulse dose, and then F must be given from shortly after birth in a daily amount appropriate for the weight of the child with some consideration for the amount of F water utilized.
L'intérêt de l'apport de fluor, en période anténatale, sur la denture est déjà démontré, mais il est aussi intéressant sur la croissance du fœtus. Une dose de 2 mg/jour en " pulse ", semble être la plus favorable ainsi qu'un apport après la naissance, compte tenu du poids et des autres sources de fluor dans l'eau utilisée.773 - Selenium administration in patients with sepsis syndrome. A prospective randomized study.
PATIENTS AND METHODS:
In this study the effect of antioxidative therapy with sodium selenite was investigated in patients with systemic inflammatory response syndrome (S. I. R. S.) and multiple organ failure. 40 patients were included in this prospective randomized study. The patients were observed over a period of 28 days. The letality rate within 28 days was excepted as main criteria. The Apache-II and the MOF-Score of Goris were used as clinical parameters. 20 patients were treated with sodium selenite over a period of 28 days.
RESULTS:
This antioxidative therapy reduced the letality rate from 40 to 15%.
Les auteurs ont étudié les effets d'une thérapie antioxydante au sélénite de sodium chez des patients souffrant du syndrome de réponse inflammatoire systémique (S.I.R.S.) et d'un dysfonctionnement multiple des organes. Parmi 40 patients inclus dans une étude randomisée prospective, et suivis durant 28 jours, 20 ont été traités par du sélénite de sodium. Le taux de mortalité à 28 jours a été le principal critère d'étude. L'Apache-II et le MOF-Score de Goris ont été utilisés comme paramètres cliniques. Les auteurs ont montré que la thérapie antioxydante diminuait le taux de mortalité de 40 à 15%.774 - Free Radicals During Hiv Infection.
In HIV infected patients, the increase of the concentration of free radicals is related to: a depletion of protective system (glutathione peroxidase, superoxide dismutase, vitamin E, selenium...), and an increased production of free radicals (superoxide anion, hydrogen peroxide, hydroxil radical) consecutive to the activation of lymphocytes and phagocyting cells, the chronic inflammation, the increased polyinsatured fatty acids concentration and lipoperoxidation, and direct or indirect effect of several pathologic agents including Mycoplasma sp. This free radical excess could impair cell membranes and generate apoptosis, the main cause of lymphocytes CD4+ depletion. After a brief review of the free radicals synthesis pathway, their potential delete rious effects and the protective systems, the role of free radicals in the pathogenesis of HIV infection are discussed in regard to data reported in the literature.
Les auteurs de cette étude décrivent les principales modifications de l'état rédox chez des patients infectés par le virus HIV. Ces auteurs font état d'une forte diminution des défenses antioxydantes chez ces patients (glutathion peroxydase, superoxyde dismutase, vitamine E, sélénium...) et d'une augmentation de la production de radicaux libres (anion superoxyde, peroxyde d'hydrogène, radical hydroxyle), consécutives à une inflammation chronique et à une activation des lymphocytes et des cellules de phagocytose. Chez ces patients une augmentation de la concentration des acides gras polyinsaturés et de la peroxydation lipidique, sont également décrites. Selon ces auteurs cet excès de radicaux libres pourrait endommagé les membranes et généré un phénomène d'apoptose, principale cause d'une déplétion en lymphocytes CD4+.775 - Plasma Selenium Levels And The Risk Of Colorectal Adenomas.
Previous research has suggested that selenium may protect against the development of colorectal neoplasia. We examined the potential chemopreventive properties of selenium against colorectal adenomas while controlling for a number of dietary and life-style factors. We conducted a cross-sectional study among patients referred for colonoscopy to University of North Carolina Hospitals. Cases had one or more pathologically confirmed adenomas, and noncases had none. Plasma selenium levels were determined using graphite furnace atomic absorption spectrometry with Zeeman background correction and platform technique. Odds ratios were calculated using logistic regression analysis adjusting for potential confounders. The mean plasma selenium concentrations for cases (n = 37) and noncases (n = 36) were 107 and 120 micrograms/l, respectively (p = 0.06). Those in the fourth quartile of plasma selenium level had 0.24 times the risk (95% confidence interval = 0.06-1.04) for colorectal adenomas of those in the first quartile. The adjusted odds ratio for colorectal adenomas was 0.58 (95% confidence interval = 0.31-1.08) for a 30 microgram/l increase in plasma selenium level. Lower plasma selenium levels were associated with multiple adenomas but not with adenoma size or location. These data support a protective effect of selenium against colorectal adenomas after adjustment for possible confounders. Selenium might be a potentially useful chemopreventive agent for colorectal neoplasia.
Les auteurs ont effectué une étude de type cas/témoins parmi les patients adressés pour coloscopie aux hôpitaux de l'université de Caroline du Nord. Ils ont comparé le taux de sélénium plasmatique chez 37 patients atteints d'un ou plusieurs adénomes coliques et chez 36 autres indemnes d'adénomes. La concentration plasmatique du sélénium a été, en moyenne, de 107 micros grammes par titre chez les patients atteints d'adénomes coliques et de 120 micros grammes par titre chez les témoins, différence à la limite de la signification (p = 0.06). Les sujets ayant le taux de sélénium le plus élevé avaient un risque d'adénome colorectal 4 fois inférieur à celui observé chez les sujets ayant le taux le plus faible. Le risque relatif d'adénome colorectal était de 40 % plus faible pour chaque augmentation de 30 micros grammes par titre du sélénium plasmatique. Les taux les plus faibles du sélénium plasmatique étaient associés à des adénomes multiples, mais sans corrélation avec la taille ou la localisation des adénomes. Ces résultats suggèrent un rôle protecteur du sélénium à l'égard du cancer colorectal.776 - Dental Caries And Dental Fluorosis At Varying Water Fluoride Concentrations.
OBJECTIVE:
The purpose of this study was to investigate the relationships between caries experience and dental fluorosis at different fluoride concentrations in drinking water. The impact of other fluoride products also was assessed.
METHOD:
This study used data from the 1986-87 National Survey of US School-children. Fluoride levels of school water were used as an indicator of the children''s water fluoride exposure. The use of fluoride drops, tablets, professional fluoride treatments, and school fluoride rinses were ascertained from caregiver questionnaires. Only children with a single continuous residence (n = 18,755) were included in this analysis.
RESULTS:
The sharpest declines in dfs and DMFS were associated with increases in water fluoride levels between 0 and 0.7 ppm F, with little additional decline between 0.7 and 1.2 ppm F. Fluorosis prevalence was 13.5 percent, 21.7 percent, 29.9 percent, and 41.4 percent for children who consumed < 0.3, 0.3 to < 0.7, 0.7 to 1.2, and >1.2 ppm F water. In addition to fluoridated water, the use of fluoride supplements was associated with both lower caries and increased fluorosis.
CONCLUSION:
A suitable trade-off between caries and fluorosis appears to occur around 0.7 ppm F. Data from this study suggest that a reconsideration of the policies concerning the most appropriate concentrations for water fluoridation might be appropriate for the United States.
Etude effectuée dans les écoles nationales aux Etats-Unis, sur l'impact de la fluorose et des caries, selon les différentes concentrations de fluor dans l'eau. Il résulte des comparaisons avec la prévalence de la fluorose que la meilleure méthode est une fluorisation avec un taux de 0,7 PPM. 777 - New Evidence On Fluoridation (see Comments).
A review of recent scientific literature reveals a consistent pattern of evidence--hip fractures, skeletal fluorosis, the effect of fluoride on bone structure, fluoride levels in bones and osteosarcomas--pointing to the existence of causal mechanisms by which fluoride damages bones. In addition, there is evidence, accepted by some eminent dental researchers and at least one leading United States proponent of fluoridation, that there is negligible benefit from ingesting fluoride, and that any (small) benefit from fluoridation comes from the action of fluoride at the surface of the teeth before fluoridated water is swallowed. Public health authorities in Australia and New Zealand have appeared reluctant to consider openly and frankly the implications of this and earlier scientific evidence unfavourable to the continuation of the fluoridation of drinking water supplies.
Les autorités sanitaires d'Australie et de Nouvelle Zélande, sont réticentes à considérer qu'il y a des modifications récentes, sur le plan scientifique, qui devraient amener à reconsidérer le problème de la fluoration systématique de l'eau.778 - Reduction Of Cancer Risk With An Oral Supplement Of Selenium.
The hypothesis that a dietary supplement of selenium (Se) may reduce cancer risk was tested experimentally in humans. Patients with histories of basal/squamous cell carcinomas of the skin were assigned randomly in double-blind fashion to daily oral supplements of either Se-enriched yeast (200 micrograms Se/day), or a low-Se yeast placebo. A total of 1312 patients recruited in 1983-1990 were followed with regular dermatologic examinations through 1993 for a total of 8269 person-years of observation. Skin cancer diagnoses were confirmed histologically. Plasma Se concentration was determined at 6-12 months intervals. All deaths and patient-reported illnesses were recorded/ reported cancers were confirmed and documented by consultation with the patient medical care providers. The results indicate that Se did not significantly affect the primary endpoints: incidences of recurrent basal/squamous cell carcinomas of the skin. However, Se- treatment was associated with reductions in several secondary endpoints: total mortality, mortality from all cancers combined, as well as the incidence of all cancers combined, lung cancer, colorectal cancer and prostate cancer. The consistencies of these associations over time, between study clinics and for the leading cancer sites strongly suggests benefits of Se-supplementation for this cohort of patients, supporting the hypothesis that supplemental Se can reduce cancer risk. Although Se did not shown protective effects against non-melanoma skin cancers, the suggested reductions in risks to other frequent cancers demand further evaluation in well controlled clinical intervention trials.
Les auteurs ont testé l'hypothèse qu'une supplémentation en sélénium pourrait réduire le risque de cancer cutané. Un total de 1312 patients ayant des antécédents de cancer de la peau (autre que le mélanome) ont reçu, par tirage au sort, un supplément de sélénium de 200 micros grammes par jour ou un placebo. Ils ont été soumis à des examens réguliers pendant une durée moyenne de 7 ans. Les résultats de l'étude ont montré que la supplémentation en sélénium n'avait pas réduit la fréquence des récidives de cancers cutanés, objectif principal de l'étude, mais qu'elle avait influencé favorablement d'autres points, avec une réduction de la mortalité globale, de la mortalité par cancer en général, et de l'incidence des cancers du poumon, du côlon et de la prostate, ces résultats demandant à être confirmés par des études prospectives spécifiques.779 - Selenium And Cardiovascular Diseases--an Update.
Dietary deficiency of selenium has been incriminated in the etiology of cardiovascular diseases. Thus, cardiomyopathy associated with low selenium intake has been described in areas of exceptionally low selenium intake and in patients receiving total parenteral nutrition. Epidemiological studies have provided some evidence for the role of selenium deficiency in the etiology of atherosclerotic disease. An inverse association between the incidence of ischaemic heart disease and selenium intake has been described in population comparisons. The results of longitudinal studies within populations are conflicting. While some investigations have observed a relationship between low serum-selenium levels and the risk of coronary disease, others have not. Final evidence for the role of selenium in preventing atherosclerotic disease can be obtained only from controlled prevention trials.
Un déficit en sélénium a été incriminé à l'origine des maladies cardiovasculaires. Ainsi, une cardiomyopathie a été rapportée dans des régions où l'apport alimentaire en sélénium est particulièrement faible et au cours de la nutrition parentérale totale. Les études épidémiologiques ont apporté des arguments en faveur du rôle d'un déficit en sélénium dans l'athérosclérose. Une relation inverse a été observée entre l'incidence des cardiopathies ischémiques dues à l'athérome des artères coronaires et l'apport en sélénium dans des études de population. Toutefois, les résultats des études de suivi dans les populations sont discordants, certaines études rapportant une relation entre des taux faibles du sélénium dans le sang et le risque de maladie coronarienne, tandis que d'autres études n'ont pas conclu à une telle association. Au total, la preuve du rôle préventif éventuel du sélénium dans la prévention de l'athérome ne pourra être apportée que par des études prospectives contrôlées.780 - Iron, Copper, And Zinc Absorption And Turnover/ The Use Of Stable Isotopes.
This overview demonstrates the increasing use of low natural abundance stable isotopes in the investigation of mineral metabolism. There are many practical problems associated with their use and analysis and their expense has limited their application in some areas such as studies in adults. Undoubtedly we will have to assess our ideas and protocols as the practical problems and their metabolic implications become better appreciated but none the less, the use of such isotopes will certainly refine our understanding of the way the body uses elements such as zinc, copper, iron and selenium and other essential elements and will enable us to determine our dietary requirements for these nutrients and to find ways of detecting more efficiently early deficiency and toxicity states.
L'utilisation d'isotopes stables pour étudier la biodisponibilité des différentes formes d'apports des minéraux et éléments traces apporterait des données d'un grand intérêt pour définir les besoins nutritionnels des populations ainsi que les limites de sécurité. Cependant les résultas d'études sont encore rares. Les auteurs de cette revue de synthèse recensent les difficultés liées à l'utilisation des isotopes stables pour les études de biodisponibilité.781 - Influence on the selenium concentration and selenium intake of infants of ingredients in Spanish homogenised infant beikosts.
Selenium (Se) concentration in 13 homogenised beikosts (any additional food used in infant nutrition different from human milk and formulas) was investigated, as well as the influence of ingredients on Se concentration in three beikost types (meat, vegetables and fish). Levels of Se varied widely, ranging from 20 micrograms/kg d.w. for mixed vegetables to 258 micrograms/kg d.w. for hake with rice. These values increased as high-protein ingredients (meat or fish) were included. Fish-based beikosts showed the highest contribution of Se, covering more than 50% of the RDA in the USA for infants from 6 to 12 months old. The best Se sources were meat and fish, and their contributions to Se concentrations in the final products were 85.3% for chicken with rice and 75% for hake and vegetables.
Mesure de la teneur en Se apporté par les formules alimentaires infantiles pour des enfants âgés de 6-12 mois. La présence de viandes, de poissons et de riz dans cette alimentation contribue pour plus de la moitié des apports recommandés en Se. Intérêt des protéines animales dans la nutrition de l'enfant pour assurer la couverture des apports recommandés dans cette population.782 - Randomized Clinical Trial Of The Effect Of Prenatal Fluoride Supplements In Preventing Dental Caries.
This randomized, double-blind study tested the caries-preventive efficacy of prenatal fluoride supplementation in 798 children followed until age 5. Initially, 1,400 women in the first trimester of pregnancy residing in communities served by fluoride-deficient drinking water were randomly assigned to one of two groups. During the last 6 months of pregnancy the treatment group received 1 mg fluoride daily in the form of a tablet and the control group received a placebo. Both treatment and control subjects were encouraged to use postnatal dietary fluoride supplements. Caries was measured in children at age 3 and 5 while fluorosis was assessed at age 5. Caries activity was very low in both study groups: 92% of children remained caries-free in the treatment group and 91% remained caries-free in the placebo group. Fluorosis was observed in 26 subjects, all classified as very mild. Overall, there were no statistically significant differences in the study groups with respect to caries and fluorosis in deciduous teeth. The study had sufficient power to detect an absolute risk reduction of 5.1% while only a 1.5% reduction was observed. These findings do not support the hypothesis that prenatal fluoride has a strong caries-preventive effect.
Etude sur l'efficacité préventive pour la carie d'une supplémentation en fluor : porte sur 798 enfants supplémentés et suivis jusqu'à l'âge de 5 ans et sur 1 400 femmes enceintes, repérées durant le 1er trimestre de la grossesse et divisées en 2 groupes, selon qu'elles ont été traitées au 3ème trimestre ou non, par 1 mg de fluor/jour. Les résultats concernent le pouvoir de réduction de la carie chez les enfants, les modalités de l'étude, ont un pouvoir discriminant suffisant pour détecter un risque de réduction de 5,1 %. Mais en fait, on a observé seulement 1,5 %, ce qui ne permet pas de conclure d'une façon significative que l'absorption prénatale de fluoride par la mère a une capacité préventive sérieuse sur la carie.783 - Nutritional Influences On Bone Mineral Density: A Cross-sectional Study In Premenopausal Women.
The association between current and past dietary intake and bone mineral density (BMD) was investigated in 994 healthy premenopausal women aged 45-49 y. BMD was measured with dual-energy X-ray absorptiometry (DXA). Dietary intake was assessed with a food- frequency questionnaire (FFQ). Energy-adjusted nutrient intakes were grouped into quartiles and mean BMD at the lumbar spine (LS), femoral neck (FN), femoral trochanter (FT), and femoral Wards (FW) were calculated. With higher intakes of zinc, magnesium, potassium, and fiber, LS BMD was significantly higher (p < 0.05-0.006), and a significant difference in LS BMD was also found between the lowest and highest quartiles for these nutrients and vitamin C intake (p < 0.05-0.01). These results remained significant after adjustment for important confounding factors. LS BMD and FT BMD were lower in women reporting a low intake of milk and fruit in early adulthood than in women with a medium or high intake (p < 0.01). High, long-term intake of these nutrients may be important to bone health, possibly because of their beneficial effect on acid-base balance.
Etude transversale montrant chez des femmes jeunes une relation entre les apports en zinc, magnésium et potassium et densité osseuse. Ces nutriments pourraient influencer la masse osseuse en influençant l'équilibre acide-base. Je ne peux pas juger s'il existe des facteurs "confondants" dans ces résultats un peu surprenant.784 - The Start Of Caries Decline And Related Fluoride Use In Norway.
The objective was to determine the start of caries decline and to estimate the use of fluorides about this time. The material consisted of service reports from the Norwegian municipal School Dental Services (SDS) and the country-based Public Dental Service (PDS), literature reports, private sales and marketing statistics, and a national health survey. The national data for the permanent dentition demonstrated a distinct decline in the average number of filled tooth surfaces from around 1970. Counties were grouped as early, &le/ 1970, and late, >or = 1971. The 5 early countries showed the decline to be evident in 1968. Several local districts reported caries reductions since 1963, following the implementation of fluoride programs. Altogether, there was a steady increase in the % of schoolchildren taking part in organized brushing or rinsing programs from 1960. In 1970, 60% of the schoolchildren regularly took part in the supervised fluoride programs. From September 1971, 0.1% fluoride dentifrices became generally available over the counter in retail stores. In 1972, 32-54% of all toothpaste delivered or sold was fluoridated. The distinct time interval between the caries decline and the availability of fluoridated toothpaste rules out the possibility of an interaction before 1971. The extensive activities with fluoride-based preventive programs in the SDS and PDS have probably been the major factors behind the decline in the late 60s/early 70s.
En Norvège, le programme de la fluorisation a été initié en 1963. A partir de 1970, on a introduit l'usage des dentifrices fluorés. Depuis, on constate une nette diminution du taux de carie. L'un des facteurs le plus évident du déclin des anomalies dentaires est le rôle joué par les programmes de prévention à l'école ou dans les services publics.785 - Zinc Supplementation And Plasma Lipid Peroxides In An Elderly Population.
OBJECTIVE:
To determine the effect of vitamin A, zinc or both on plasma lipid peroxides in a healthy elderly population.
DESIGN:
Double-blind randomized controlled trial supplementation of vitamin A and zinc.
SETTINGS:
Public home for elderly people, in Rome, Italy.
SUBJECTS:
A total of 178 residents of a Public home for elderly people were evaluated regarding health and nutritional status. 136 gave a written consensus to participate in the trial and were randomized in four groups of treatment. 118 elderly completed the trial.
INTERVENTION:
Three months supplementation of the following treatments: (1) vitamin A (800 micrograms retinol palmitate)/ (2) zinc (25 mg zinc as sulphate)/ (3) vitamin A and zinc (800 micrograms retinol palmitate and 25 mg zinc as sulphate)/ (4) placebo (starch containing capsules).
MAIN OUTCOME MEASURES:
Plasma lipid peroxides (TBA-RS) were measured before and after supplementation.
RESULTS:
Zinc supplementation was associated with a decrease in plasma lipid peroxides (beta = -0.19/ 95% confidence levels: -0.37, -0.002/ p- value = 0.05) after adjusting for sex, smoking habits, baseline plasma lipid peroxides and vitamin A plasma levels.
CONCLUSION:
Zinc supplementation decreased plasma lipid peroxides while vitamin A had no effect in this elderly population. Adequate zinc intake or supplementation could play an important role in the prevention and/ or modulation of diseases in the elderly people.
Rôle du zinc dans la prévention des maladies chez les sujets âgés.786 - Determination Of Selenium Levels In Dairy Products And Drinks By Hydride Generation atomic absorption spectrometry.
The selenium concentrations in different dairy products and drinks in the Mediterranean coastal area of southeastern Spain have been determined by hydride generation atomic absorption spectrometry. Mineralization was carried out with an HNO3-HClO4 mixture (4:1) in a thermostatted sand bath. Selenium determination was carried out by the standard addition method. Mean concentrations obtained in diary products varied from 6.87 ng/g (rice pudding) to 178.90 ng/g (caramel custard), and those in drinks from 0.256 micrograms/l (wine) to 2.879 micrograms/l (pineapple juice). Repeatability, expressed as relative standard deviation, ranged from 5.06% to 13.25%. The results obtained from the recovery studies were proximate to 100%. Considering the mean daily individual consumption of these foods in Andalusia (southern Spain), the daily dietary intake of selenium supplied by this source is 5.869 micrograms per person per day.
Les auteurs de cette étude ont analysés les teneurs en Se de divers produits alimentaires (laitiers et boissons) consommés dans le sud de l'Espagne. Les concentrations moyennes des produits analysés variaient de 6,87ng/g (gâteau de riz) à 178,90ng/g (crème caramel) pour les produits laitiers et de 0,256µg/L (vin) à 2,879µg/g (jus d'ananas). Selon les auteurs de ce travail, la consommation de ces produits contribuerait à un apport moyen de 5,87 µg/j par personne. Les apports recommandés en Se sont de 100 à 200µg/j.787 - A Pilot Study Of Antioxidant Intake In Patients With Cholesterol Gallstones.
Whereas macronutrient intake has been extensively investigated in an attempt to unravel the pathogenesis of human cholesterol gallstones, theoretical considerations and animal models suggest that deficits in micronutrient antioxidants may be more relevant. We report a pilot study of this aspect. The plan was to obtain 7-d weighed food inventories over a 6mo period from equal numbers of patients who had not consciously changed their diets, patients who were on low-fat diets and age- and gender-matched controls. Food tables would be used to derive daily intakes of 16 known antioxidants, essential amino acids, and essential fatty acids. Under- reporting of food intake, a recognized drawback of this dietary method, would be sought retrospectively by reference to a key publication giving minimum cut- off limits for ratios of energy intakes to basal metabolic rates. There were 18 pairs for study
ANALYSIS:
of data for the 9 pairs involving patients on their normal diets showed no differences in the intakes of energy, macronutrients, and cholesterol, but the patients ingested lower amounts of 10 among 16 antioxidants (p < 0.05 for methionine, alpha-tocopherol, manganese, and vitamin D/ 0.05 < p < 0. 10 for cysteine, beta-carotene, vitamin C, selenium, zinc, and phosphorus). Both subsets of patients ingested lower amounts of linoleic acid (diet unchanged P kappa 0.009, changed p = 0.026) and several essential amino acids than did matched controls. Institution of a low-fat diet caused the expected fall in intakes of energy and saturated fatty acids such that the deficit in alpha-tocopherol was amplified, but substitution of fruit and vegetables by the patients resulted in a fortuitous increase in vitamin C, beta-carotene, and manganese intake. Retrospective analysis confirmed under-reporting of food intake by all four subsets of subjects but there was no significant difference in the mean ratio of energy intake to estimated basal metabolic rate in the subset of patients who had not consciously altered their diets and the subset of matched controls. Furthermore, the lower daily intake of alpha-tocopherol and linoleic acid by these patients persisted when results were expressed relative to total fat consumption. The results support the hypothesis that insufficiency of dietary antioxidants, particularly alpha-tocopherol, may be germane to human gallstone disease/ they also suggest that low intakes of linoleic acid and essential amino acids may he relevant. Because of the small sample sizes, however, these deductions should be regarded as tentative, pending confirmation by biochemical analysis of blood and especially of hepatic bile.
De nombreux travaux ont été consacrés à l'effet des macro nutriments sur la survenue des calculs vésiculaires de cholestérol, mais un déficit en micro nutriments antioxydants mérite également d'être pris en considération. Les auteurs ont effectué une enquête alimentaire détaillée, pendant une durée de 6 mois, chez 18 patients atteints de lithiase vésiculaire, dont 9 suivaient leur régime usuel et 9 suivaient un régime pauvre en graisses, par comparaison avec 18 sujets témoins appariés pour l'âge et le sexe. Les résultats de cette enquête nutritionnelle montrent que les patients atteints de lithiase vésiculaire avaient un apport plus faible que les témoins en anti-oxydants d'origine alimentaire, notamment en alpha-tocophérol, ainsi qu'en acide linoléique et en certains acides aminés essentiels. L'influence de ces différences d'apport sur la formation des calculs biliaires cholestéroliques ne pourra être démontrée que si elle correspond à des différences de teneur de ces composants dans la bile.788 - Fluoride Bioavailability - Nutritional And Clinical Aspects.
Dietary fluoride obtained from food and water is efficiently absorbed from both the stomach and small intestine without regulation. A variety of dietary factors have been identified that either decrease or increase fluoride absorption and utilization. About half of absorbed fluoride is quickly taken-up by developing bone and teeth, and the remainder is excreted in the urine. The amount of fluoride excreted in the urine increases as bone growth slows. Nearly all of total body fluoride, which is second among the trace elements only to iron, is found in the skeleton. Although fluoride''s unique role in mineralization provides the basis for its recognition as a beneficial trace element for dental health of humans, a more subtle role of fluoride in the mineralization of bone is also likely to exist. As with other essential trace elements, fluoride''s action is biphasic in nature in that toxicity (fluorosis) can occur. Therapeutic effects of fluoride in the treatment of osteoporosis continue to be studied, and recent developments in this area point to a mitogenic role of fluoride in osteoblast cell proliferation. Recognition of fluoride essentiality for human health, rather than just being classified as beneficial, is likely to be forthcoming especially if reduction of a chronic disease is added to the criteria that establish a recommended dietary allowance.
L'absorption de fluor par le tube digestif n'est pas régulée par la muqueuse intestinale, à l'inverse du fer par exemple, mais des facteurs externes l'augmentent ou la diminuent. La moitié de la quantité de fluor absorbée est rapidement captée par l'os et la dent, le reste est éliminé par l'urine. Les actions métaboliques du fluor sont plus subtiles, elles peuvent être bi-phasiques, à certains moments toxiques, à d'autres bénéfiques. L'action thérapeutique a été bien étudiée et récemment, son rôle mitogène sur les ostéoblastes rend compte de son importance dans la dentinogenèse, l'ostéogenèse et leurs modifications. Sur le plan de la santé, en général, on commence seulement à bien connaître le bénéfice du fluor sur la réduction de certaines maladies chroniques.789 - Fluorosis In Children And Sources Of Fluoride Around Lake Elementaita Region Of Kenya.
During a project to determine the fluoride levels of milk in Lake Elementaita region, the authors were astonished by the high levels of fluorosis in children living in the area. With special reference to children, a study was designed to establish and describe the levels of dental fluorosis and also to determine other sources of fluoride to the community. The levels of dental fluorosis were recorded using Thylstrup and Fejerskov classification method (TF) for children aged between 2-14 years. Biodata information, feeding habits and details of fluoride history were collected using a questionnaire form filled out with the help of teachers and/or parents
RESULTS:
pertain to both continuous and non-continuous residents for both primary and permanent dentition. The high fluorosis level of 95.8% was associated with the fluoride concentration in the community water supply and food. Food samples analysed for fluoride include cows milk (the major source of nutrients for the children in the area), vegetables and water. Fluoride levels in drinking water from different boreholes were high, varying from 2.0-20.9 mug/mL-1. Milk fluoride levels in samples from seven localities ranged from 0.05-0.22 mug/mL-1 (mean) and an individual animal range of 0.02-0.34 mug//g. Vegetables had fluoride levels between 7.9-59.3 mug//g with an exception of one with 296.6 mug//g. The soils in which the vegetables are grown had over 1000 ppm. This being a landscape formed by the process of faulting and volcanic activity, the dust from Lake Elementaita also had high fluoride concentration of 2300 mug//g.
En Finlande, il y a un taux très élevé de fluorose dans la région du lac Elementaita. Il y a des taux élevés de fluor dans l'eau, dans les aliments, le lait et les légumes. Cela varie de 2 à 20 mg/l. C'est une région volcanique, il est probable que l'apport de fluor vient des poussières retombées du volcan sur les terres avoisinantes. 790 - Relations Between Environment And Endemic Fluorosis In Hohhot Region, Inner Mongolia.
Results are reported of a comprehensive investigation into fluoride levels in drinking water and other environmental characteristics, and their relation to endemic fluorosis, in Hohhot Region, Inner Mongolia.
L'abstract est un peu court pour que l'on puisse se faire une opinion sur l'importance de l'article, qui concerne les investigations sur l'absorption de fluor par l'eau dans une région de la Mongolie intérieure. Il concerne une région de la Mongolie intérieure de la république populaire de Chine. Région de plaine diluviale et alluviale avec une très forte prévalence de la fluorose. Plus de 30 000 personnes ont été étudiées dont 79 % ont une fluorose dentaire et 13,3 % une fluorose du squelette. Les études comparatives de la concentration en fluor de l'air, du sol et de l'eau démontrent que c'est la consommation par l'eau qui est responsable, dans 65 % des cas, des lésions de fluorose.791 - Endemic Fluorosis In Mexico.
The significant mining of fluorspar in Mexico is evidence of the presence of fluoride in the Mexican subsoil. Therefore, the appearance of endemic fluorosis in some areas of our country may be a consequence of the contamination of aquifers by fluorspar deposits. In endemic areas, fluoride levels in drinking water are higher than the Mexican guideline of 1.5 mg/L in both urban and rural locations. Furthermore, health risk effects related to fluoride exposure have been identified in at least two states. Nevertheless, endemic fluorosis is still an essentially unrecognized environmental health problem in Mexico, although it is affecting around five million people. Some improvements have been obtained by the introduction of educational programs and by the emerging of research programs in some universities. However, more work is needed in order to reduce the prevalent risks.
Il y a un risque de fluorose dans, au minimum, 2 états du Mexique, en raison de la haute teneur en fluor des sols et des nappes phréatiques. Ces zones concernent 5 millions d'habitants. Il faut donc éduquer ces populations et faire rechercher, par les études universitaires, dans quelles mesures il faut réduire l'apport de fluor, dans les programmes politiques.792 - Magnesium Kinetics In Adolescent Girls Determined Using Stable Isotopes: Effects Of High And Low Calcium Intake.
Magnesium kinetics were measured in five adolescent girls who were participating in a calcium balance study. Two calcium levels were fed in a randomized crossover design. After an acclimation period, 26Mg was consumed orally and 25Mg was given intravenously, and then blood, urine, and feces were collected for 14 days. Total magnesium and percent enrichment were determined, and data were fitted to a eight-compartment model. There was no significant difference between high and low calcium intakes for any of the parameters examined. Mean values for control (800 mg/day) and high (1,800 mg/day) calcium intake were as follows: Mg intake, 305 +/- 30 and 286 +/- 9 mg/day/ absorption (percent), 44 +/- 7 and 39 +/- 9/ absorption (mg/day), 134 +/- 35 and 110 +/- 28/ urinary excretion, 96 +/- 22 and 101 +/- 31 mg /day/ fecal excretion, 175 +/- 32 and 200 +/- 11 mg/day/ and magnesium balance, 13 +/- 35 and -34 +/- 48 mg/day, respectively
IN CONCLUSION:
high calcium intake did not alter magnesium kinetics or balance in adolescent girls.
Chez des adolescentes, une étude utilisant le double marquage isotopique (26Mg et 25Mg) montre qu'une supplémentation en Ca (1800 mg/jour vs 800 mg/jour) ne modifie pas la biodisponibilité du Mg. La possibilité d'une inhibition de l'absorption du Mg lors d'une augmentation des apports calciques a été souvent évoquée. Ce résultat est important compte tenu des recommandations actuelles visant à augmenter l'apport calcique pendant la croissance pour la constitution d'un capital osseux optimum. La notion selon laquelle il existerait une compétition entre Ca et Mg pour l'absorption digestive est donc erronée.793 - The Nutritional Situation In Switzerland - Implications For Disease Prevent.
Diet is of importance in the prevention of most chronic diseases. Dietary habits are measured regularly in most countries. In Switzerland data on groups and individuals are available, but a comprehensive dietary survey is still lacking. Since World War II an overall decrease in foods rich in complex carbohydrates and an increase in foods rich in fat available per capita of the population has been observed. Data on individuals show that 30%, i.e. 39% of men and 22% of women, in Switzerland are overweight (BMI &le/25). The percentages of energy intake as fat and sugar are higher, and the percentage of energy intake as complex carbohydrates lower than recommended. 7% of women and 6% of men consume hazardous amounts of alcohol (men &le/60 g/day, women &le/20 g/day). Marginal vitamin deficiencies are observed in various population groups for the vitamins B1, B2, B6, folic acid and vitamin C. Due to the fortification of salt and the widespread use of American wheat rich in selenium, iodine and selenium intake can be considered adequate. An insufficient intake of calcium is demonstrated in the elderly and an insufficient intake of calcium and iron in women. As a consequence of this nutritional situation, the first national nutritional guidelines have recently been published in Switzerland.
En l'absence d'enquête complète sur les consommations alimentaires en Suisse, cette revue de synthèse tente d'assembler diverses enquêtes partielles pour dresser un bilan de la situation. Parmi les micronutriments, des insuffisances d'apport sont relevées pour les vitamines B1, B2, B6, l'acide folique et la vitamine C, ainsi que pour le calcium et le fer chez les femmes et le calcium chez les personnes âgées.794 - Nutrition Survey In Dental Fluorosis-afflicted Areas.
The fluoride (F) intake, diet, and health status of children in two dental fluorosis-afflicted areas in the Province of Jiangxi, China were studied in an attempt to correlate nutritional status with dental fluorosis. The relationship between milk consumption and the incidence of dental fluorosis among the children was stressed in this study. Average body weight of the children approximated that of the national standard. Protein intake was above the national standard of 0.75 g/kg body weight/day, but the protein was derived mainly from plant sources. Calcium intake was found to be insufficient. Based on the diet and fluoride intake of the studied groups, the areas with a better nutritional status were found to have a lower incidence of dental fluorosis. The incidence among milk-consuming children was lower than that of non-milk-consuming children.
Etude effectuée en Chine, dans la province de Jiangxi, basée sur les apports de fluor dans les aliments des groupes étudiés et démontre que dans les zones où il y a un statut nutritionnel meilleur, la fluorose dentaire est beaucoup plus basse. Elle démontre aussi que, chez les enfants, ceux qui boivent du lait ont une meilleure santé dentaire que ceux qui n'en boivent pas.795 - Blood And Urine Acid-base Status Of Premenopausal Omnivorous And Vegetarian Women.
The effect of long-term differences in diet composition on whole-body acid-base status was examined in thirty-three young healthy females. The volunteers were recruited from two separate groups matched approximately for age, height and weight/ one group regularly ate meat (omnivores/ n 20) and one group did not (vegetarians/ n 13). All subjects completed a 7 d weighed intake of food, and from their dietary records, total energy, carbohydrate (CHO), fat and protein content were estimated using computer-based food composition tables. During this week they reported to the laboratory on two occasions, following an overnight fast and separated by at least 48 h. Arterialized venous blood samples were obtained on each visit and these were analysed for blood acid-base status. Haemoglobin and packed cell volume, serum total cholesterol and HDL-cholesterol, serum albumin and total protein were also determined. Two 24 h urine collections were completed/ the volume was recorded and samples were analysed for pH, titratable acid and Mg and Ca concentration. Total energy intake of the omnivores was greater (p = 0.0003) than that of the vegetarian group. Dietary intake of CHO (p = 0.024), fat (p = 0.0054) and protein (p = 0.0002) were higher in the omnivorous group than in the vegetarians. There were no differences between the two groups with respect to blood CO2 partial pressure, plasma HCO3- and blood base excess, but blood pH was slightly higher in the omnivores (p = 0.064). Measures of urine acid-base status suggested a lower pH in the omnivore group, but this difference was not statistically significant/ a greater titratable acid output was observed with the omnivorous group compared with the vegetarians (48.9 (SE 20.3) v. 35.3 (SE 23.3) mEq/24h/ p = 0.018). Although the dietary intake of Ca was not different between the two groups, urinary Ca excretion of the omnivores was significantly higher (3.87 (SD 1.34) v. 3.22 (SD 1.20) mmol/24 h) than that of the vegetarians (p = 0.014). It is suggested that the higher protein intake of the omnivores resulted in an increase in urinary total acid excretion, which may explain the higher rate of Ca excretion.
Cet article compare le statut acide-base de végétariens et d'omnivores. Il faut noter que les omnivores ont des apports en énergie, protéines et gras plus importants que les végétariens. L'acidité titrable urinaire est augmentée chez les omnivores mais il n'existe pas de différence du pH sanguin. Cette augmentation de l'acidité titrable s'accompagne d'une augmentation de l'excrétion urinaire du calcium. Ces résultats ne montrent cependant en aucun cas un effet néfaste d'un régime omnivore sur le tissu osseux.796 - Chemoprevention For Colorectal Carcinoma.
The literature on chemoprevention for colorectal carcinoma can be summarized as follows: (1) Aspirin and NSAIDs usage can decrease polyp formation and promote polyp regression and have a strong epidemiologic link to colorectal cancer prevention. (2) Fiber intake is strongly associated with a decreased incidence of colorectal carcinoma. Whether supplemental fiber can prevent colorectal neoplasia is not yet clear. (3) Calcium and vitamin D intake is inversely proportional to the risk of developing colorectal carcinoma. Prospective trials make the role of supplemental calcium as a chemoprotective agent unclear: (4) Chemoprevention is an exciting area of research. More work needs to be done to establish the precise steps necessary for neoplastic transformation of cells so that pharmaceuticals can be developed to target carcinogenesis at several levels.
Les auteurs ont effectué une revue générale approfondie des travaux concernant les possibilités de chimioprévention du cancer colorectal. L'aspirine et les anti-inflammatoires non stéroïdiens inhibent la formation des polypes et favorisent leur régression, et exercent un effet préventif démontré à l'égard du cancer colorectal. Cet effet passe probablement par l'inhibition de l'activité de la cyclooxygénase (COX) et la prévention de la formation de radicaux libres dotés d'une action carcinogène. Un apport alimentaire élevé en fibres est nettement associé à une faible incidence du cancer colorectal, mais l'effet préventif d'une supplémentation en fibres n'est pas concluant. L'apport en calcium et en vitamine D apparaît inversement proportionnel au risque de développer un cancer colorectal, mais l'efficacité préventive d'un supplémentation en calcium n'est pas clairement démontrée. Au total, la chimioprévention apparaît comme un champ de recherches prometteur. Cependant, une connaissance plus précise des étapes de la transformation néoplasique des cellules intestinales reste nécessaire pour cibler les interventions pharmacologiques destinées à les inhiber et à prévenir ainsi le développement et la progression du cancer colorectal.797 - Calcium Supplementation And The Risk Of Preeclampsia In Ecuadorian Pregnant Teenagers.
OBJECTIVE:
To determine whether increased calcium intake (2 g/day) in pregnancy is effective in reducing the risk of preeclampsia in pregnant teenagers.
METHOD:
The present study was a prospective, randomized, double-blind, controlled clinical trial. Two hundred sixty teenaged pregnant girls attending the Hospital Gineco-Obstetrico Isidro Ayora in Quito, Ecuador, were included
SELECTION CRITERIA:
were age less than 17.5 years, nulliparity, first prenatal visit before 20 weeks'' gestation, and residency in Quito (2800-m altitude). We used a table of random numbers to assign 125 girls to receive 2000 mg of elemental calcium daily, beginning at 20 weeks of gestation and continuing until delivery/ 135 women in the control group received a placebo. Blood pressure (BP) was measured twice every 4 weeks until delivery and at 48 hours after delivery. The diagnosis of preeclampsia was defined as BP greater than 140/90 mmHg on at least two occasions more than 6 hours apart and proteinuria greater than 30 mg/dL (over one cross by dipstick on two occasions 4-24 hours apart).
RESULTS:
The average daily calcium intake in this population was approximately 51% of the Recommended Dietary Allowance. Calcium supplementation was associated with a significantly decreased risk of preeclampsia (risk reduction 12.35%/ p < .001), with 3.2% (n = 4) developing preeclampsia in the treatment group versus 15.5% (n = 21) in the placebo group. Moreover, calcium supplementation led to a reduction in systolic BP of 9.1 mmHg and in diastolic BP of 6.0 mmHg.
CONCLUSIONS:
These results suggest that calcium supplementation during pregnancy in populations with low calcium intake is a safe, effective, and inexpensive preventive measure that significantly reduces the risk of preeclampsia.
Etude contrôle, randomisée. Grand intérêt pour la prévention de la pré-éclampsie dans une population aux apports de calcium insuffisants pendant la grossesse. 798 - A Randomized Controlled Trial Of The Effect Of Third-trimester Calcium Supplementation On Maternal Hemodynamic Function.
OBJECTIVE:
To determine the effect of third-trimester calcium supplementation on maternal hemodynamic function.
METHOD:
Pregnant women were randomized to receive either 1.5 g of elemental calcium or placebo for 6 weeks during the third trimester. Using Doppler technique, maternal hemodynamic characteristics were measured at baseline, at 2 hours after the first dose of study drug, and at the completion of 6 weeks. Serum, dietary, and urinary calcium levels were also assessed. Power calculation indicated the need to study ten subjects in each group to detect a 1.2 L (20%) difference in cardiac output between groups, assuming a mean of 6.2 +/- 1.0 L/minute. Data were analyzed by analysis of variance for repeated measures, Student t test, Mann-Whitney U test, and Fisher exact test.
RESULTS:
Twenty- three women enrolled, and 18 completed the study. There were no statistically significant differences in demographic characteristics or in serum, dietary, or urinary calcium levels between the two groups. There were also no statistically significant differences in hemodynamic function over time within the calcium supplementation or placebo group (p >.05/ analysis of variance for repeated measures). After 6 weeks, there were no significant differences between the calcium- and placebo-treated subjects in any hemodynamic measurement. Specifically, there was not a statistically significant difference in cardiac output (7.3 +/- 1.2 L/minute versus 8.0 +/- 0.9 L/minute/ p = .09) between the calcium- and placebo-treated groups.
CONCLUSIONS:
These findings suggest that third-trimester calcium supplementation does not significantly alter cardiac output. The mechanism by which calcium supplementation lowers blood pressure remains to be elucidated.
Intéressant dans la discussion sur la supplémentation en calcium au cours de la grossesse pour prévenir l'hypertension artérielle.799 - The Effect Of Calcium Supplementation On Bone Density During Lactation And After Weaning (see Comments).
BACKGROUND:
Women may lose bone during lactation because of calcium lost in breast milk. We studied whether calcium supplementation prevents bone loss during lactation or augments bone gain after weaning.
METHOD:
We conducted two randomized, placebo-controlled trials of calcium supplementation (1 g per day) in postpartum women. In one trial (the study of lactation), 97 lactating and 99 nonlactating women were enrolled a mean (+/-SD) of 16+/-2 days postpartum. In the second trial (the study of weaning), 95 lactating women who weaned their infants in the 2 months after enrollment and 92 nonlactating women were enrolled 5.6+/-0.8 months postpartum. The bone density of the total body, lumbar spine, and forearm was measured at enrollment and after three and six months.
RESULTS:
The bone density of the lumbar spine decreased by 4.2 percent in the lactating women receiving calcium and by 4.9 percent in those receiving placebo and increased by 2.2 and 0.4 percent, respectively, in the nonlactating women (p <0.001 for the effect of lactation/ p = 0.01 for the effect of calcium). After weaning, the bone density of the lumbar spine increased by 5.9 percent in the lactating women receiving calcium and by 4.4 percent in those receiving placebo/ it increased by 2.5 and 1.6 percent, respectively, in the nonlactating women (p <0.001 for the effects of lactation and calcium). There was no effect of either lactation or calcium supplementation on bone density in the forearm, and there was no effect of calcium supplementation on the calcium concentration in breast milk.
CONCLUSION:
Calcium supplementation does not prevent bone loss during lactation and only slightly enhances the gain in bone density after weaning.
Référence essentielle, même si elle détruit le concept de l'intérêt d'une supplémentation calcique de la femme allaitante. 800 - Acute Changes In Serum Calcium And Parathyroid Hormone Circulating Levels Induced By The Oral Intake Of Five Currently Available Calcium Salts In Healthy Male Volunteers.
Several calcium supplements are currently available and many of them are marketed without proper comparison of the bioavailability of the actual preparations. The aim of the present trial was to evaluate and compare the acute changes in serum calcium (Ca) and parathyroid hormone (PTH) levels following the oral administration of a vehicle and of five calcium salts currently prescribed in Western Europe. No significant changes in serum Ca or PTH levels were observed after administration of the vehicle. All calcium salts induced significant increases in serum Ca and decreases in serum PTH compared to baseline values. Comparison of the six response curves revealed a significantly greater increase in serum Ca and a greater decrease in serum PTH after each of the calcium salts than observed after the vehicle. However, no statistically significant differences were observed between the different calcium salts for serum Ca increments. The decrease in serum PTH observed after administration of an ossein- hydroxyapatite complex was significantly less important than after the four other calcium salts, even if statistically different than after vehicle. When assessing the area under the curve (AUC) of PTH values, we observed that calcium carbonate and citrate induce a significantly greater decrease in serum PTH than the other calcium salts which are, however, statistically more active than the vehicle. Serum PTH is decreased under the lower limit of the normal range (10 pg/ml), between t60 and t120 for calcium carbonate and citrate and between t60 and t90 for calcium gluconolactate while the mean PTH values remain within the normal range throughout the study with calcium pidolate, the ossein-hydroxyapatite complex and the vehicle
IN CONCLUSION:
all calcium preparations significantly increase serum calcium and decrease serum parathormone, compared to what is observed after oral intake of a vehicle. However, significant differences in suppression of parathormone are observed between the different calcium preparations and might be of importance for their clinical use.
Variations de la PTH et de la calcémie après une charge orale aiguë en différents sels de calcium. Tous les sels de calcium induisent une augmentation de la calcémie et une baisse de la PTH. Celle-ci serait plus importante avec le citrate et le carbonate de calcium. Il reste à savoir si l'effet à long terme serait identique.801 - Calcium And Phosphorus Supplementation Of Iron-fortified Infant Formula: No.
One objective of this clinical trial was to determine whether calcium and phosphorus supplementation of infant formula affects the iron status of healthy full-term infants. One hundred three infants were randomly assigned to receive iron-fortified, cow milk-based infant formula (465 mg Ca and 317 mg P/L) or the same formula with added calcium glycerophosphate (1800 mg Ca and 1390 mg P/L) for 9 mo. Reported calcium intake for supplemented infants was about four times that of control infants, ranging from a mean of 1741 mg/d at baseline to 1563 mg/d at 9 mo. There was no difference by treatment group in mean or median change from baseline of serum ferritin, total-iron- binding capacity, erythrocyte protoporphyrin, or hematocrit at 4 and 9 mo after enrollment. Incidence of iron deficiency was similar for both groups and no infant developed iron deficiency anemia during the trial. This study indicates that the well-documented inhibitory effect of calcium and phosphorus on iron absorption is not clinically important in infants fed iron-fortified infant formula.
L'étude montre que l'effet inhibiteur du Ca et du Phosphore sur l'absorption du fer n'est pas cliniquement important, il n'y a pas de différence significative dans ce travail entre la prise isolée de fer et la prise de fer et de Ca.802 - Sports Drinks Hazard To Teeth.
OBJECTIVE:
To determine the dental hazards associated with sports supplement drinks by investigating the chemicophysical properties of eight brands of sports drinks.
METHOD:
The pH and titratable acidity against 0.1 M NaOH was measured. Calcium, phosphate, and fluoride concentrations and viscosities of Carbolode, Gatorade, High Five, Isostar, Lucozade Sport Lemon, Lucozade Sport Orange, Maxim, and PSP22 were determined.
RESULTS:
The pH values of the drinks ranged from 4.46 (Maxim) to 2.38 (Isostar) and therefore were below the critical pH value (5.5) for enamel demineralization. Both Lucozade varieties had high titratable acidities (16.30 ml 0.1 M NaOH to neutrality) with Gatorade, High Five, and Isostar displaying intermediate titratable acidity, although Isostar had 74.5 ppm calcium and 63.6 ppm phosphate. The fluoride concentration of all drinks was low, and none of the drinks was particularly viscous (range 3.1-1.4 mPa.s).
CONCLUSION:
The chemicophysical analyses indicate that all the sports drinks in this study have erosive potential. However, drinks with higher pH, lower titratable acidity, and higher concentrations of calcium, phosphate, and fluoride will reduce this erosive potential.
Le rôle des boissons des sportifs sur la santé en général. 8 boissons ont été étudiées au Royaume-Uni. Toutes ont un potentiel érosif certain en raison de leur pH, de l'acidité titrable élevée, des sucres, etc. Leur concentration en fluor est basse et aucune de ces boissons n'est particulièrement visqueuse. En conclusion, les analyses physico-chimiques indiquent que toutes ces boissons pour sportifs ont un potentiel érosif sur l'émail. Cependant, celles qui ont le pH le plus haut, l'acidité titrable la plus basse et la plus haute concentration en calcium, en phosphate et en fluor, réduisent ce potentiel érosif.803 - Evidence For The Nutritional Essentiality Of Boron.
Since 1981, circumstantial evidence has been accumulating which suggests that boron is an essential nutrient for higher animals including humans/ that is, a dietary deprivation of boron consistently results in changed biological functions that could be construed as detrimental and are preventable or reversible by an intake of physiological amounts of boron. Nonetheless, boron is not generally recognized as essential or nutritionally important for humans, probably because a specific biochemical function for boron has not been elucidated, or as demonstrated for plants, it has not been shown necessary to complete the life cycle. However, findings from human and animal experiments show that boron is a dynamic trace element that can affect the metabolism or utilization of numerous substances involved in life processes including calcium, copper, magnesium, nitrogen, glucose, triglyceride, reactive oxygen, and estrogen. Through these effects, boron can affect the function or composition of several body systems including blood, brain, and skeleton. Two hypotheses have appeared to account for these multiple effects. One hypothesis is that boron is a negative regulator that influences a number of metabolic pathways by competitively inhibiting some key enzyme reactions. The other hypothesis is that boron has a function involved in cell membrane function, stability, or structure such that it influences the response to hormone action, transmembrane signalling, or transmembrane movement of regulatory cations or anions. Regardless of the fact that the function of boron remains undefined, the findings from human and animal studies indicate that boron should be recognized as being of nutritional importance.
Article général sur le bore. Le bore est un élément essentiel des plantes et des animaux, son essentialité chez l'homme est à l'étude. Ses rôles biologiques sont multiples et affectent de nombreux métabolismes parmi lesquels le Ca, le Cu, le Mg, les glucides, les lipides, l'insuline les dérivés de l'oxygène et les oestrogènes. Le bore, en agissant sur les membranes cellulaires, pourrait moduler les réponses hormonales des mécanismes auxquels il participe / le bore agit également en inhibant l'activité enzymatique de nombreuses enzymes des métabolisme généraux (glucides).804 - Calcium Insufficiency And Fracture Risk.
No abstract available.
Bonne revue des relations entre l'insuffisance calcique et le risque de fracture.805 - Reversal Of Fluorosis In Children.
Large populations consume fluoride-contaminated water, especially in developing countries. The toxic effects of fluorosis take three forms: clinical, skeletal and dental. Research thus far indicates that the manifestations of fluorosis are irreversible. However, it has been observed that the ingestion of calcium, vitamin C or vitamin D, individually, is effective in protection from fluoride toxicity to a certain extent. Therefore, a double blind control trial was conducted to examine the effect of a combination of calcium, vitamin D3 and ascorbic acid supplementation in fluorosis-affected children. In the present study, 25 children were selected from an area consuming water containing 4.5 p.p.m. of fluoride, All the children were in the age group 6-12 years and weighed 18-30 kg. They were graded for clinical, radiological and dental fluorosis and relevant biochemical parameters. Grade I skeletal fluorosis and all grades of the manifestation of dental and clinical fluorosis were observed. The children were given ascorbic acid, calcium and vitamin D3 well below the toxic dosages in a double blind manner using lactose as a placebo. Follow up revealed a significant improvement in dental, clinical and skeletal fluorosis and relevant biochemical parameters in these children. Thus, the study indicated that fluorosis can be reversed, at least in children, by a therapeutic regimen that is fairly cheap, simple and easily available and without any side effects.
Il s'agit d'une étude japonaise démontrant que la fluorose, jusqu'ici réputée trouble irréversible, peut cependant chez l'enfant être capable d'évoluer en rétrocession lorsque les apports de calcium, de vitamine C et de vitamine D, sont bien adaptés.806 - Calcium Supplements.
No abstract available.
Revue807 - Calcium Homeostasis During Pregnancy And Lactation In Primiparous And Multiparous Women With Sub-adequate Calcium Intakes.
Low calcium intake and parity may be factors affecting calcium homeostasis during pregnancy and lactation. In this study, changes of urinary indices related to bone and renal adjustments of calcium homeostasis were measured in each trimester of pregnancy and in the lactation period, in primiparous (n=35) and multiparous (n=25) women with habitual calcium intakes about half the RDA for this nutrient, in comparison to never-pregnant (control) women (n=23) with similar calcium intakes. Calcium and phosphorous urinary excretion did not change during pregnancy but decreased in the lactation period, similarly in primiparas and mutiparas (p<0.01). Calcium urinary excretion was not different between pregnant and control women, indicating that renal conservation may contribute to calcium homeostasis during pregnancy with sub-adequate as opposed to adequate calcium intakes. In lactation, urinary calcium excretion was 32% lower than in the controls, indicating renal calcium conservation also in this period. Hydroxyproline urinary excretion increased during pregnancy and decreased in the lactation period, both in primiparas (p<0.001) and multiparas (p<0.05). Excretion was, on average, 152% and 80% higher than excretion in the control women, in the third trimester of pregnancy and in lactation, respectively, consistent with increased bone mobilization in these periods. Considering all pregnant women, hydroxyproline excretion in the third trimester correlated weakly but significantly with pregnancy weight gain (r=0.275, p=0.04). Multiparity did not affect the renal handling of calcium and phosphorous during pregnancy and lactation, neither hydroxyproline excretion in lactation. However, hydroxyproline excretion in the third trimester of pregnancy was 58% higher in primiparas compared to multiparas, in spite of similar weight gains during pregnancy. This could be due to differences between primiparas and multiparas in the composition of tissue gained during pregnancy or to an adaptive mechanism in multiparas to protect maternal bone from excessive calcium loss during pregnancy.
A conserver, compte tenu du relatif intérêt pour décrire le métabolisme du calcium au cours de la grossesse et dans le post-partum chez les femmes allaitantes.808 - Validation Of A Short Food Frequency Questionnaire For Assessment Of Dietary Calcium Intake In Women.
OBJECTIVE:
To assess the ability of a short food frequency questionnaire to measure dietary calcium intake in women.
DESIGN:
Estimates of calcium intake from the food frequency questionnaire were compared with those from seven-day estimated records in 58 Caucasian women aged 25-49 years in Dunedin, New Zealand.
SUBJECTS:
Subjects were recruited through poster and newspaper advertising around the central business district of Dunedin, New Zealand. Of 69 subjects initially recruited, nine failed to complete diet records and two were excluded on the basis that their diet record was unlikely to represent habitual intake.
RESULTS:
Mean dietary calcium intakes were 808.1mg/day from the estimated record and 776.9mg/day from the questionnaire. The mean difference in intake by the two methods (31.1mg, SD = 234.0, 95% CI = -30.4-92.7, p = 0.3) did not differ significantly from zero. The questionnaire classified women consuming less than 800mg calcium per day with 78% specificity. 81% of subjects when classified by the records fell into the same or adjacent quartiles when classified by the questionnaire. Only two subjects were grossly misclassified.
CONCLUSION:
The short food frequency questionnaire could be used to assess mean dietary calcium intake in young to middle aged women. The specificity of the questionnaire is high in identifying women who consume < 800mg calcium/day, therefore it could be used to target interventions for those with intakes below this level.
Bonne validation d'un questionnaire évaluant la ration calcique des femmes.809 - Calcium And Colorectal Epithelial Cell Proliferation In Ulcerative Colitis.
In persons at higher risk for colon cancer (e.g., those with sporadic adenoma or ulcerative colitis), compared to those at lower risk, colonic epithelial cell proliferation kinetics are altered. We have shown previously that calcium supplementation appears to normalize the distribution of proliferating cells without affecting the proliferation rate in the colorectal mucosa of sporadic adenoma patients. In a pilot randomized, double-blind, placebo-controlled, clinical trial conducted concurrently with our previously published sporadic adenoma trial, we tested whether calcium supplementation can also modulate cell proliferation kinetics in patients with ulcerative colitis. Ulcerative colitis patients (n = 31) were randomized to placebo or 2.0 g of supplemental calcium daily. Colorectal epithelial cell proliferation was determined by immunohistochemical detection of proliferating cell nuclear antigen labeling of cells in nonprep rectal biopsies taken at randomization and after 2 months treatment. All biopsies were scored by one reviewer. Differences in mean follow- up minus baseline labeling index (LI/ the proportion of colon crypt epithelial cells that were labeled) and in the phi(h) (proportion of labeled cells that were in the upper 40% of the crypts) were compared with analysis of covariance. Pill-taking adherence was 97%. Biopsy- scoring reliability was high (r = 0.89). The pooled baseline LI and phi(h) were 6.3% and 5.6%, respectively. The LI in the calcium group decreased by 0.5% (proportionately, 3%) more than in the placebo group (p = 0.91). Similarly, the phi(h) in the calcium group decreased by 0.3% (proportionately, 10%) more than in the placebo group (p = 0.85). This pilot study does not suggest that 2.0 g of calcium as calcium carbonate daily can substantially normalize either the rate or distribution of proliferating cells over a 2-month period in the colon crypts of patients with ulcerative colitis/ a more definitive answer to the question of whether calcium may be effective would require a study with a larger sample size and/or other study design modifications.
Etude clinique randomisée en double aveugle contre placebo sur l'influence d'un large supplément de calcium (2 g par jour) sur la prolifération cellulaire de la muqueuse colorectale chez 31 patients souffrant de colite ulcérante. Ce travail ne permet pas de conclure à l'efficacité de 2 g de Ca (en carbonate) par jour sur la normalisation en 2 mois de la distribution et du taux de prolifération cellulaire dans les cryptes du côlon.810 - Dietary magnesium intake in a French adult population.
Magnesium intake was assessed using six 24-h dietary records during a 1-year period in 5,448 subjects (3,111 women 35-60 yrs old and 2,337 men 45-60 yrs old) in the SU.VI.MAX cohort, selected at a national level in France. The overall mean dietary intake was estimated at 369 +/- 106 mg/day in men and 280 +/- 84 mg/day in women. 77 per cent of women and 72 per cent of men had dietary magnesium intakes lower than recommended dietary allowances/ 23 per cent of women and 18 per cent of men consumed less than 2/3 of these RDA. A strong positive correlation existed between energy and magnesium intake (r = 0.79/ p < 10(-4)). Slight variations were observed according to socio-professional and educational levels and place of residence. Cereal products represented the main contribution in both men (21 per cent) and women (19.8 per cent). In men, the second source was represented by alcoholic beverages (11.7 per cent), which were a lower source of magnesium in women (5.5 per cent). Dairy products, vegetables, meat and poultry were the other main sources of dietary magnesium intake.
Les apports en Mg ont été évalués chez les sujets participant à la cohorte SUVIMAX en France. Plus de 70 % des sujets ont des apports inférieurs aux ANC (6 mg de Mg/kg de poids corporel/jour). 18 % des hommes et 23 % des femmes de cette cohorte ont des apports inférieurs aux 2/3 des ANC. Ces résultats confirment que l'évolution de l'alimentation moderne a retenti de façon importante sur les apports en Mg, d'où la fréquence du déficit marginal.811 - Cancer Of The Prostate: A Nutritional Disease?
In summary, epidemiologic and laboratory evidence increasingly demonstrate that nutritional factors, especially reduced fat intake, soy proteins, vitamin E derivatives, and selenium, may have a protective effect against prostate cancer. The experimental observation that low-fat diets and soy protein extracts may influence the progression of established tumors, rather than inhibiting etiologic factors, is particularly intriguing because it may serve to help explain the paradox whereby the incidence of clinical prostate cancer shows wide geographic variation, yet the evidence persists that the incidence of microfocal tumors is essentially the same worldwide. These observations, plus the likelihood that nutrition trials are likely to have little in the way of toxicity that would preclude their completion, argue that such trials should be performed. It is estimated that 30% to 50% of human malignancies may be related to dietary factors, and although the feasibility of trials involving low-fat diets has been proved in ongoing trials for colon and breast cancer, no similar study exists for prostate malignancy. Critics of epidemiologic research argue that data derived from case- control studies are subject to recall bias and are thus artifactual. Indeed, many researchers now believe that the breast cancer-dietary fat hypothesis has been discredited. The major difference between the prostate cancer and breast cancer literature is the remarkable consistency of the cohort studies. In these studies, exposure is determined prospectively and is therefore free from recall bias. In this sense they more closely resemble a clinical trial. The majority of cohort studies involving dietary fat and breast cancer have been negative. We believe that these data justify large-scale trials in the area of prevention of prostate cancer. One such proposed study already submitted for National Institutes of Health funding from a consortium of centers is the Prostate Interventional Nutrition Study (PINS), modeled after the Women''s Interventional Nutrition Study, which investigates the effect of low-fat diets in women receiving therapy for node-positive breast cancer. The PINS study will be limited to men who have detectable serum PSA levels but no other clinical evidence of disease after radical prostatectomy. All subjects will receive nutritional guidance, with randomization between a control arm receiving the currently recommended 30% fat diet and an interventional arm in which a 15% fat diet is supplemented with soy protein, vitamin E, and selenium. The end points for evaluation will be compared with progression based on changes in PSA and the time of onset of clinical, as opposed to biochemical, disease. Single-institution trials involving groups thought to be at high risk of developing clinical cancer--including men with persistently elevated PSA levels, two negative prostate biopsies, high-grade prostatic intraepithelial neoplasia on biopsy, and a strong family history of prostate cancer--are being initiated at MSKCC and other institutions.
CONCLUSION:
We have reviewed the evidence that nutritional factors play a role in the progression rate of prostate cancer and may help to explain the geographic variation in the incidence observed. However, without well-controlled prospective trials, the attractive hypothesis that nutrition plays a role in tumor progression remains simply an attractive hypothesis. To date, no definite proof of a preventive effect has been shown in a study that will withstand rigid scientific scrutiny. The opportunity exists, however, for the urologic community, working together with experts in the area of nutrition, not only to advance our understanding of prostate tumorigenesis, but to rebut those critics of modern medical technology who claim that we have ignored the total or holistic approach to healing.
Les auteurs rappellent les données épidémiologiques qui tendent à montrer une influence protectrice, vis à vis du cancer prostatique, de certains facteurs nutritionnels, notamment un régime pauvre en graisses, les protéines du soja, la vitamine E et le sélénium. Les données disponibles montrent que ces facteurs agiraient plus en retardant la progression des tumeurs déclarées, qu'en inhibant leur formation. En se basant sur ces données, une enquête prospective multicentrique à large échelle a été conçue pour tester l'effet d''un régime pauvre en graisses supplémenté en protéines du soja, en vitamine E et en sélénium chez des hommes atteints de cancer de la prostate, traités par prostatectomie totale, en suivant l'évolution des PSA (antigènes prostatiques spécifiques) par prélèvements sanguins répétés. Cette étude dénommée PINS (acronyme de Prostate Interventional Nutrition Study, ou étude d'intervention nutritionnelle dans le cancer prostatique) devrait permettre d'établir si ce type de régime, par comparaison avec le régime usuel comportant 30% de graisses, est susceptible de ralentir l'évolution du cancer prostatique, alors que les études cas-témoin rétrospectives n'ont, jusqu'ici, pas pu en apporter la preuve indiscutable.812 - Nutrition And Cardiovascular Disease.
The association between nutrition and coronary heart disease is mainly due to the effect of nutrients on serum lipids and lipoproteins. Cholesterol intake does not play a very important role for plasma cholesterol although there is a strong interindividual difference in response. The intake of saturated fatty acids strongly negatively affects plasma low-density lipoprotein cholesterol concentration while mono- and polyunsaturated fatty acids are generally regarded as beneficial. Omega-3 fatty acids mainly decrease triglyceride concentration while omega-6 polyunsaturated fatty acids mainly affect low-density lipoprotein cholesterol. Other nutrients which affect risk for coronary heart disease are dietary fiber, calcium, magnesium, iron, antioxidants as well as vitamins. Dietary fiber decrease intake of calories and fat, while iron and antioxidants play a role in oxidative modification of low-density lipoproteins. A low intake would lead to an accelerated uptake of low-density lipoprotein into the macrophage. Yet, intervention studies have not shown conclusively the benefit of a high-dose supplementation of the antioxidants vitamin E or beta-carotene on coronary heart disease. Homocysteine plasma concentration is influenced by folate as well as vitamin B6 and B12. Whether a high- dose supplementation with these substances does not only decrease plasma concentrations of homocysteine but also positively influence the course of coronary heart disease remains to be established.
Les auteurs passent en revue les facteurs nutritionnels connus pour intervenir dans la survenue de l'athérome coronarien, et les stratégies préventives qui peuvent s'en déduire. Les acides gras saturés augmentent le taux plasmatique du cholestérol [des lipoprotéines de basse densité (LDL-cholesterol)] ou " mauvais " cholestérol), tandis que les acides gras mono-insaturés et poly insaturés ont un effet bénéfique .Parmi les autres nutriments susceptibles de réduire le risque d'athérome figurent les fibres, le calcium, le magnésium, le fer, les antioxydants et certaines vitamines. Toutefois, aucune étude interventionnelle n'a, jusqu'ici, démontré l'effet protecteur d'une supplémentation par de fortes doses de vitamine E ou de bêta-carotène à l'égard de l'athérome coronarien. En ce qui concerne l'homo cystéine, autre facteur athérogène, son taux plasmatique peut être réduit grâce à une supplémentation en acide folique et en vitamines B6 et B12, mais il reste à déterminer si cette réduction exerce un effet favorable sur le cours de la maladie coronarienne.813 - Acute Oral Calcium-sodium Citrate Load In Healthy Males. Effects On Acid-base And Mineral Metabolism, Oxalate And Other Risk Factors Of Stone Formation In Urine.
The currently preferred calcium preparations for supplementation of food vary widely with respect to calcium availability, effects on systemic mineral metabolism, acid-base status, and the calciuria- induced risk of urinary tract stone formation. In eight healthy males we studied the response to an acute load with alkali (sodium)- containing soluble calcium citrate (CSC) (molar ratio calcium/sodium /citrate approx. = 1/1/1), when taken in three different doses (10, 20, 30 mmol calcium) together with a continental breakfast. Intestinal calcium absorption, serum calcium, calcitonin, parathyroid hormone (PTH) other markers of bone metabolism, net acid excretion and calcium oxalate crystallization in urine were evaluated. CSC evoked a dose-dependent increase in calcium absorption, calcium in serum and urine, but no overt hypercalcemia, and calciuria was low relative to the excess calcium ingested/ PTH fell and calcitonin rose (p <0.05 vs. breakfast alone), but the diet- independent markers of bone resorption declined only insignificantly, while the markers of bone formation and turnover remained unchanged. There was a significant ''once-daily'' effect (= cumulative 24 h postload response) of CSC: a decrease in urinary cyclic AMP, phosphorus, and ammonium, and an increase in urinary bicarbonate. Soon after CSC intake, urinary calcium oxalate and hydroxyapatite supersaturation increased dose-dependently, the calcium oxalate crystal diameter was increased, but crystal aggregation time, which is crucial for stone formation, remained statistically unchanged. Thus, CSC provides calcium in a bioavailable form, creates mild systemic alkalinisation and inhibition of bone resorption, but leaves the risk of developing urinary stones unchanged. Comparative long-term studies on bone growth and the maintenance of bone health, using alkali-containing versus alkali-free calcium citrate, appear worthwhile.
Cette étude étudie l'effet aigu d'une supplémentation de 400 à 1200 mg de citrate de calcium. Rien d'inattendu dans les résultats. Une étude sur les caractéristiques de l'agrégation cristalline suggérant une absence d'effet lithogène de la supplémentation en citrate de calcium.814 - Preterm Labour During Oral Magnesium Supplementation In Uncomplicated Pregnancies.
The null hypothesis of this study was that oral magnesium supplementation would not affect the incidence of preterm contractions, preterm labour and associated neonatal complications. 530 women with low-risk pregnancies were recruited until the 18th week of gestation and assigned to receive 15 mmol magnesium citrate once daily PO (n=265) or no supplementation (n=265). 240 patients and 250 controls completed the study. The patients receiving magnesium had a significantly lower rate of hospitalization due to threatened preterm labour (6.6% vs. 12.0%, p < 0.05), significantly higher birth weight (3377 ±/ 503 vs. 3287 ±/ 477 g, p < 0,05) and the rates of preterm labour and birth weight < 2500 g were lower in the patients receiving magnesium, but not significantly so (4.6% vs. 8.0% and 2.9% vs. 4.8%, respectively). The rate of admissions to the neonatal care unit was 1.6% in both groups. The results show that a daily oral supplementation of 15 mmol (365 mg) magnesium exercises a positive influence on the rate of hospitalizations due to threatened preterm labour, and also on the birth weight.
D'autres études disent le contraire, l'efficacité dépend peut-être de la population d'origine. Il est probable que le résultat positif sur le poids de naissance soit dû au hasard. L'effet sur l'hospitalisation peut se concevoir par l'effet intéressant du magnésium sur les douleurs abdominales de la femme enceinte. Cette étude n'est pas assez rigoureuse pour conclure.815 - Prevention Of Atherosclerosis: The Potential Role Of Antioxidants.
Evidence is increasing that oxidation of low-density lipoprotein cholesterol may be instrumental in atherogenesis. As a result a number of studies have been undertaken to evaluate the effects of antioxidant vitamins, beta carotene, selenium, and monounsaturated fat on coronary artery disease
RESULTS:
in many instances have been promising, particularly in the case of vitamin E supplements. Studies of pro-oxidants, such as iron and copper, are inconclusive at this time, and a trial to assess the value of probucol in hypercholesterolemic patients is currently under way.
Revue générale sur le rôle potentiel des antioxydants dans la prévention de l'athérosclérose. Les auteurs soulignent le rôle de mieux en mieux reconnu de l'oxydation des lipoprotéines de basse densité ( LDL) à l'origine de l'athérosclérose. De ce fait, de nombreuses études se sont efforcées d'évaluer les effets de stratégies antioxydantes utilisant des vitamines antioxydantes, le bétacarotène, le sélénium et les graisses mono insaturées dans la prévention de l'athérome coronarien. Les résultats de ces études apparaissent, dans l'ensemble, prometteurs, mais des études prospectives randomisées seront nécessaires pour identifier les mesures préventives efficaces.816 - Salt Overload Does Not Modify Plasma Atrial Natriuretic Peptide Or vasopressin During Pregnancy In Rats.
The present study was carried out to determine whether the increased salt intake induce by increased specific sodium appetite in pregnant rats modifies water-salt homeostasis throughout pregnancy. Two groups of pregnant rats were used, one fed ad libitum with a normal sodium (NS) diet consisting of standard rat chow and distilled water, and the other fed with a high-sodium (HS) diet with free access to chow, distilled water plus saline solution (1.5% NaCl). Virgin rats in dioestrus were also studied as non-pregnant controls. Pregnant animals were studied on days 4, 9, 14, 20 and 21 of gestation at which time body weight, water and saline intake, sodium excretion, plasma atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) concentrations, as well as plasma osmolality were determined. Data showed that water intake was higher in the NS group, but total fluid intake (water plus saline) was higher in the HS group throughout pregnancy. Dietary sodium intake was the same for both groups but total sodium intake (chow plus saline) was 60-98% higher in the HS rats. Pregnant HS rats excreted more fluid (35-50%) and sodium (up to 100%) compared with NS rats, indicating that the animals could change their renal excretion in response to a 2.5-fold higher dietary sodium intake compared with the control level. Salt satiety during pregnancy did not modify plasma ANP concentration. In both groups of pregnant rats ANP levels increased 3-fold on day 14 without significant alteration in sodium excretion, suggesting that the natriuretic action of ANP is attenuated at least after the second week of pregnancy. High sodium intake did not change plasma AVP concentration or osmolality and both groups showed the same gradual decrease in plasma osmolality (approximately 8 mosmol kg-1) at the end of pregnancy that was not accompanied by decreased plasma AVP concentration. The present data show that rats maintain the special homeostatic equilibrium that occurs in normal pregnancy even when they are allowed to increase sodium intake to satisfy their salt appetite during this period of the reproductive cycle.
Les rates gestantes qui disposaient de solution de NaCl à 1,5% en plus de l'eau, consommaient un supplément de solution saline allant jusqu' à doubler leur apport en Na+ et en eau (distillée + saline). L'excrétion de ces surplus a parfaitement compensé les apports et restauré l'homéostasie. Ces régulations n'ont pas impliqué, ni l'ANP ni l'AVP qui étaient identiques chez les 2 groupes de gestantes, avec et sans supplément de NaCl.817 - Salt And Water Absorption In The Human Colon: A Modern Appraisal.
The basic mechanisms underlying salt and water transport in the colon of man in health and disease are reviewed under the headings/ general description of Na+ absorptive processes (electrogenic Na+ absorption, electroneutral NaCl absorption and Na+ and water absorption by colonic crypts)/ salt and water absorption in the diseased colon (colonic resection) and Future research.
Etude à visée cognitive (physiologique). Mécanismes de l'absorption intestinale de l'eau et du sel (NaCl).818 - Beverage Use And Risk For Kidney Stones In Women.
This prospective cohort study with 8 years of follow-up examined the association between the intake of 17 beverages and the risk for kidney stones in women. 81 093 women in the Nurses'' Health Study, USA, who were 40 to 65 years of age in 1986 and had no history of kidney stones were recruited. Beverage use and diet were assessed in 1986 and 1990 with a validated, self-administered food-frequency questionnaire. The main outcome measure was incident symptomatic kidney stones. During 553 081 person-years of follow-up over an 8- year period, 719 cases of kidney stones were documented. After risk factors other than fluid intake were controlled for, the relative risk for stone formation for women in the highest quintile of total fluid intake compared with women in the lowest quintile was 0.62 (95% confidence interval (CI), 0.48-0.80). Inclusion of consumption of specific beverages in the multivariate model added to prediction of risk for kidney stones (p <0.001). In a multivariate model that adjusted simultaneously for the 17 beverages and other possible risk factors, risk for stone formation decreased by the following amount for each 240-ml serving consumed daily: 10% (CI, 5-15%) for caffeinated coffee, 9% (CI, 2-15%) for decaffeinated coffee, 8% (CI, 1-15%) for tea and 59% (CI, 32-75%) for wine. In contrast, a 44% (CI, 9-92%) increase in risk was seen for each 240-ml serving of grape- fruit juice consumed daily. It was concluded that an increase in total fluid intake can reduce risk for kidney stones and the choice of beverage may be meaningful.
Reprise du matériel d'étude épidémiologique des mêmes auteurs sur l'incidence de la lithiase urinaire, portant sur une cohorte de 81 093 femmes âgées initialement de 40 à 55 ans et suivies pendant 8 ans, sous l'angle de l'influence de la quantité et de la nature des boissons sur le risque lithiasique. Les auteurs mettent en évidence une influence favorable d'un volume de boissons supérieur à 2 litres par jour et de la consommation de café (caféiné ou décaféiné) et de thé, mais une influence très défavorable du jus de pamplemousse.819 - Differences In Fertility Associated With Caffeinated Beverage consumption.
The effect of caffeine consumption on fertility was examinedprospectively between 1990 and 1992 in 210 women aged 31.8 plus or minus 4.2 years from Northern California, USA. Women reported on caffeinated beverage consumption and pregnancy status monthly. Odds ratios for becoming pregnant were calculated for high and moderate vs. low consumption. No significant association was found for any of the caffeinated beverages except tea. Drinking one-half cup or more of tea daily approximately doubled the odds of conception per cycle. These data suggest that caffeine may not be the responsible agent for variation in fertility associated with consumption of the beverages examined.
Etude de la relation entre consommation de boissons contenant de la caféine et fertilité dans un groupe de 210 femmes âgées de 31,8 40,2 ans. En conclusion, les différences de fécondité notées entre les différents sous-groupes ne semblent pas imputables à la caféine apportées par les boissons.820 - Restoration Of Water And Electrolyte Balance After Exercise.
No abstract available.
Cet article passe en revue les problèmes liés à la réhydratation après l'exercice et montre que cette dernière n'est efficace que si l'on compense les pertes sudorales en Na+, en plus de la restauration du volume d'eau perdu. Les boissons de réhydratation orale utilisées en clinique médicale possèdent des taux de Na+ voisins de la limite supérieure du Na+ sudoral (80 mosmol/l). Mais cette boisson est trop riche en sel (non palatable) pour être utilisée comme boisson du sport. Les boissons commerciales pour le sport contiennent généralement entre 10 et 30 mosmol/l de Na+, quantité généralement insuffisante. Les " soft drinks " n'en contiennent pas du tout et sont impropres à réaliser une réhydratation efficace. La solution est de boire plus que les pertes sudorales des boissons enrichies modérément en Na+. Le K+ n'apporte rien de plus.821 - Plasma Volume Expansion With Oral Fluids In Hypohydrated Men At Rest And During Exercise.
BACKGROUND:
The purpose for this study was to evaluate various carbohydrate (CHO)-electrolyte fluid formulations for consumption by astronauts to maintain or restore their plasma volume (PV) and total body water (TBW) during and after extravehicular activity (exercise experiment, EE) and for a few hours before reentry and immediately after landing (rest experiment RE). Hypothesis: That fluid formulation electrolyte content would be more important than osmotic (Osm) content for increasing or maintaining PV during the RE and EE.
METHOD:
In the RE, 5 healthy men (23-44 yr), previously dehydrated for 24 h, drank 6 fluid formulations (Water, 19.6 Na, 157 Na, 19.6 Na + glucose, and the prepared drinks Performanceregistered trade mark and Power)- one each at weekly intervals, and then sat for 70 min. In the EE, four healthy 24-h dehydrated men (30-46 yr) exercised for 70 min supine on a cycle ergometer (load = 71 ±/ 1% peak VO2).
RESULTS:
Rest: Subjects who consumed formulations with total Osm concentrations nearer the normal range (157 Na - 270 mOsm ·/ /kg, Performanceregistered trade mark with 19.6 mEq ·/ L-1 Na - 380 mOsm, and to some extent power with 23.5 mEq ·/ L-1 Na - 390 mOsm) had the greater increases in PV/ intake of drink 157 Na, with the largest Na content, induced the greatest hypervolemia of 7.6% (p < 0.05). The various additional ions, in addition to 19.6 Na, probably contributed to the 4.6% (p < 0.05) hypervolemia with Performanceregistered trade mark. Water was not effective. Exercise: Stabilization of PV between 15-70 min was not related to drink total CHO, Na or Osm content. Performanceregistered trade mark and 157 Na were no more effective than 19.6 Na or 19.6 Na + glu for PV stabilization. Water was the least effective. Regulatory mechanisms controlling PV during exercise appear to be independent of oral fluid formulation Osm-electrolyte content.
CONCLUSION:
Drink cation (sodium) content is more important that its total osmotic content for increasing plasma volume at rest. Fluid formulations with greater hypervolemic action in resting subjects may not be as effective during exercise/ therefore different formulations for use during exercise appear to be necessary.
Etude à visée physiopathologique explorant la meilleure composition des boissons, en terme de soluté, pour la restauration ou le maintien du volume plasmatique dans diverses conditions aérospatiales.822 - Analytic Assessment Of The Various Bioimpedance Methods Used To Estimate Body Water.
The merits of a single-frequency (SF) bioimpedance method were evaluated. Mathematical simulation was performed to determine the effect of tissue change on resistance and reactance. Dilution results were reanalyzed, and resistance and parallel reactance were used to predict the intracellular water for 2 groups (8 men after elective coronary artery bypass graft surgery and 48 healthy men aged 26-57 years). The amount of intracellular and extracellular water conduction at any SF can vary with tissue change, and reactance at any SF is affected by all tissue parameters. Impedance modeling provided a good prediction of dilution intracellular and extracellular water, but an SF method did not. Intracellular, extracellular and total body water were equally predicted at all frequencies by SF resistance and parallel reactance. It is concluded that extracellular and intracellular water are best measured through modeling, because only at the zero and infinite frequencies are the results sensitive only to extracellular and intracellular water. At all other frequencies there are other effects.
Cet article montre la supériorité de la modélisation pour l'évaluation de l'eau intra- et extracellulaire sur l'impédance mono-fréquence.823 - Effect Of Maternal Hydration On Fetal Renal Pyelectasis.
OBJECTIVE:
To assess the effect of maternal hydration on fetalpyelectasis.
METHOD:
Thirteen pregnant women with fetal pyelectasis and 13 controls matched for gestational age were recruited during the same period. Ultrasound and Doppler studies and maternal urine specific gravity measurements were carried out before and after maternal oral hydration. The data were analyzed by either a two- or three-factor analysis of variance.
RESULTS:
Renal artery Doppler pulsatility index was significantly greater in the study group than in the controls (2.37 versus 1.83/ p =.009) and this finding was unaffected by maternal hydration status. After hydration, the maternal urinary specific gravity decreased significantly (1.018 versus 1.009/ p < .001), the amniotic fluid index (AFI) increased significantly (14.27 versus 18.24 cm/ p < .001), and the fetal renal pelvis diameter increased significantly (0.29 versus 0.46 cm/ p =.002) in both the study and control groups. Renal pelvis anteroposterior diameter after hydration did not differ significantly whether the fetal bladder was full or empty (0.7 versus 0.6 cm/ p =.1). In this study, each subject served as her own control (ie, from before to after hydration). Three of 13 controls met the diagnostic criteria for pyelectasis after maternal hydration.
CONCLUSIONS:
The AFI increases after maternal hydration in both normal fetuses and those with pyelectasis. The fetal renal pelvis anteroposterior diameter increases with maternal hydration in both normal fetuses and those with pyelectasis and is independent of the state of the fetal bladder. The renal artery Doppler pulsatility index is significantly greater in fetuses with pyelectasis than in controls.
Cet article montre que le mécanisme d'augmentation de la quantité de liquide dans l'hyperhydration maternelle est bien une augmentation de la production urinaire foetale.824 - Volume Repletion After Exercise-induced Volume Depletion In Humans:replacement Of Water And Sodium Losses.
Sodium and water loss during, and replacement after, exercise-inducedvolume depletion was investigated in six volunteers volume depleted by 1.89 +/- 0.17% (SD) of body mass by intermittent exercise in a warm, humid environment. Subjects exercised in a large, open plastic bag, allowing collection of all sweat secreted during exercise. For over 60 min beginning 40 min after the end of exercise, subjects ingested drinks containing 0, 25, 50, or 100 mmol/l sodium (trials 0, 25, 50, and 100) in a volume (ml) equivalent to 150% of the mass lost (g) by volume depletion. Body mass loss and sweat electrolyte (Na+, K+, and Cl-) loss were the same on each trial. The measured sweat sodium concentration was 49.2 +/- 18.5 mmol/l, and the total loss (63.9 +/- 38.7 mmol) was greater than that ingested on trials 0 and 25. Urine production over the 6-h recovery period was inversely related to the amount of sodium ingested. Subjects were in whole body negative sodium balance on trials 0 (-104 +/- 48 mmol) and 25 (-65 + /- 30 mmol) and essentially in balance on trial 50 (-13 +/- 29 mmol) but were in positive sodium balance on trial 100 (75 +/- 40 mmol). Only on trial 100 were subjects in positive fluid balance at the end of the study. There was a large urinary loss of potassium over the recovery period on trial 100, despite a negligible intake during volume repletion. These results confirm the importance of replacement of sodium as well as water for volume repletion after sweat loss. The sodium intake on trial 100 was appropriate for acute fluid balance restoration, but its consequences for potassium levels must be considered to be undesirable in terms of whole body electrolyte homeostasis for anything other than the short term.
A la suite d'un exercice en ambiance chaude et humide ayant entraîné une déshydratation modérée (2% PC) avec une perte en Na+ d'environ 65 mmol, la réhydratation a été réalisée sur une période de 6 heures avec un volume hydrique 150% plus élevé que les pertes. Les apports sodés inférieurs à la perte (entre 0 et 50 mmol) conduisent à des balances sodées négatives / l'apport de 100 mmol conduit à une balance sodée positive. L'importance de l'apport de Na+ est donc démontré, par contre, il est nécessaire d'expertiser les conséquences des pertes en K+ qui sont importantes dans les urines en période de récupération malgré la quasi absence d'ingestion de cet ion.825 - Monday To Wednesday Tiredness And Thirst.
No abstract available.
Nouvelle incrimination de l'insuffisance du boire dans la fatigue chronique. Mais l'étude n'est pas suffisamment étagée.826 - Fluid Balance In Bacterial Meningitis In Children.
As part of a nationwide study in children with bacterial meningitiswe analyzed fluid balance in 25 patients treated in our hospital during a three years period in 1984-1986. Thirteen (48%) children had hypo-osmolal and eight (32%) had iso-osmolal dehydration on admission. One child (4%) had SIADH (Syndrome of inappropriate antidiuretic hormone secretion), and the disorder recovered quickly. Thus, only four (16%) children had normal fluid balance. The fluids needed to correct dehydration were estimated individually in each child/ after its correction, maintenance fluids were restricted in all patients to 2/3 of normal, however, containing NaCl more than usually, 5 mEq/100 ml. We found important to re-evaluate fluid therapy every 4 to 6 hours during the first two days. In four children (16%) with findings suggestive for developing SIADH, the given fluids were further restricted, and SIADH was avoided. Urine Na + concentrations remained low for the first 24 hours in all the 12 children with hypo-osmolal dehydration, despite of its immediate correction by Ringer-type solutions. Our findings support the importance of an effective correction of initial hypovolemia, subsequent prophylactic maintenance fluid restriction, and sufficient NaCl supplementation for children with bacterial meningitis.
Etude rétrospective de l'équilibre hydroélectrolytique chez 25 enfants hospitalisés entre 1984 et 1986 pour méningite bactérienne. 16% seulement avaient un équilibre hydroélectrolytique normal, un enfant avait un syndrome de sécrétion mal soignée d'hormone anti-diurétique, les autres étaient déshydratés (hypo ou normo natrémiques). Nécessité de corriger et de surveiller l'équilibre hydroélectrolytique dans les méningites bactériennes.827 - Bioimpedance Spectrometry In The Determination Of Body Water compartments: Accuracy And Clinical Significance.
Bioelectrical impedance analysis (BIA) offers the potential for asimple, portable and relatively inexpensive technique for the in vivo measurement of total body water (TBW). The potential of BIA as a technique of body composition analysis is even greater when one considers that body water can be used as a surrogate measure of lean body mass. However, BIA has not found universal acceptance even with the introduction of multi-frequency BIA (MFBIA) which, potentially, may improve the predictive accuracy of the measurement. There are a number of reasons for this lack of acceptance, although perhaps the major reason is that no single algorithm has been developed which can be applied to all subject groups. This may be due, in part, to the commonly used wrist-to-ankle protocol which is not indicated by the basic theory of bioimpedance, where the body is considered as five interconnecting cylinders. Several workers have suggested the use of segmental BIA measurements to provide a protocol more in keeping with basic theory. However, there are other difficulties associated with the application of BIA, such as effects of hydration and ion status, posture and fluid distribution. A further putative advantage of MFBIA is the independent assessment not only of TBW but also of the extracellular fluid volume (ECW), hence heralding the possibility of being able to assess the fluid distribution between these compartments
RESULTS:
of studies in this area have been, to date, mixed. Whereas strong relationships of impedance values at low frequencies with ECW, and at high frequencies with TBW, have been reported, changes in impedance are not always well correlated with changes in the size of the fluid compartments (assessed by alternative and more direct means) in pathological conditions. Furthermore, the theoretical advantages of Cole-Cole modelling over selected frequency prediction have not always been apparent. This review will consider the principles, methodology and applications of BIA. The principles and methodology will be considered in relation to the basic theory of BIA and difficulties experienced in its application. The relative merits of single and multiple frequency BIA will be addressed, with particular attention to the latter''s role in the assessment of compartmental fluid volumes.
Cet article correspond à une revue supplémentaire sur le principe, la méthodologie et les applications de la mesure des comportements hydriques corporels par impédancemétrie bioélectrique.828 - Changes In Renal Function With Aging.
Despite losing 20%-25% of their original kidney volume, olderindividuals maintain body fluid hemostasis under most circumstances/ however, their ability to withstand environmental, disease-related, or iatrogenic stresses becomes progressively narrowed. Glomerular filtration rates fall with each decade, accompanied by limitations on sodium conservation, potassium ion secretion, and acid excretion. Medications used by older patients are a common cause of hyperkalemia through a number of pathophysiologic mechanisms. In addition, water homeostasis frequently fails due to defects in thirst, urinary concentrating ability, and free water excretion, resulting in hypernatremia or hyponatremia in many sick older patients.
Bonne revue sur le vieillissement.829 - Impact Of Ingested Liquids On 24-hour Ambulatory Ph Tests.
A prospective investigation of the impact of ingested liquids on 24-hr pH test scores was conducted. Eighty-two patients contributed 142 samples. The liquids used were coffee/tea (N = 35), water (N = 32), fruit juice (N = 29), cola (N = 34), and beer (N = 12). The pH of cola, juice, and beer are approximately 3.0. The parameters studied included: total test time, total drink time, total minutes of pH < 4.0 during drink, minutes of < pH 4.0 10 min before drink, and minutes of pH < 4.0 10 min following drink
ANALYSIS:
was performed using one-way ANOVA and repeated measures. Age of patients, total test time, and total time pH < 4.0 were not significantly different (p > 0.05). The total time to consume the drink was significantly greater (p < 0.05) for beer than all other liquids. The total time (7.7 +/- 6.0 min) pH < 4.0 for cola was significantly different (p < 0.023) than beer (3.3 +/- 3.7 min), tea/coffee (1.4 +/- 6.5 min), and water (1.1 +/- 2.5 min). The percentage of total time pH < 4.0 was not significantly different (p > 0.05) among any of the liquids. The percentage of time pH < 4.0 during the drink was the highest for cola (63 +/- 47%) and juice (51 +/- 57%)/ water, coffee/tea, and beer were not significantly different (p > 0.05). Although the impact of cola and juice were the greatest, none of these had an impact that exceeded 0.5%. The lack of impact of beer appears to be due to the increased period of time it takes to consume. We conclude that the impact of ingested fluids is minimal and can probably be disregarded in most patient groups.
Etude de l'impact de la consommation de différent type de boisson sur le pH gastrooesophagien. Les résultats indiquent très peu de différence (non significative) selon la nature de la boisson. La nature des boissons courantes a peu ou pas d'impact sur le pH digestif.830 - Hyperthermia and dehydration-related deaths associated with intentional rapid weight loss in three collegiate wrestlers--North Carolina, Wisconsin, and Michigan, November-December 1997.
During November 7-December 9, 1997, three previously healthy collegiate wrestlers in different states died while each was engaged in a program of rapid weight loss to qualify for competition. In the hours preceding the official weigh-in, all three wrestlers engaged in a similar rapid weight-loss regimen that promoted dehydration through perspiration and resulted in hyperthermia. The wrestlers restricted food and fluid intake and attempted to maximize sweat losses by wearing vapor-impermeable suits under cotton warm-up suits and exercising vigorously in hot environments. This report summarizes the investigation of these three cases.
Cet article est là pour rappeler que l'on peut aujourd'hui encore décéder d'hyperthermie associée à la déshydratation en cas de restriction volontaire d'apport hydrique lors de régimes hypocaloriques avec privation d'eau.831 - New Patterns Of Drinking-water Consumption: Results Of A Pilot Study.
A pilot study on water consumption was carried out in the Quebec City region in April and May 1996 with 125 people using a 24-h recall plus a 2-day diary. Consumption of drinking water via liquid and food was assessed as well as the type of water consumed (tap, bottle or filtered water) and place of consumption (home or away from home). Most of the people (56%) were drinking some bottled water or filtered tap water and 25% of water intake was away from home. Food consumption was found to be a non-significant source of drinking- water intake. The average water consumption was nearly similar in exclusively tap-water consumers and bottled- or filtered-water consumers (1.5 vs. 1.7 l/day, p = 0.29) but two-thirds of the consumption in this last group is natural water, while it is mixed water in the bottled/filtered-water group. No significant difference in amounts consumed were found according to age, but older people drank hot beverages and soup more often. The present pilot-study was weakened by a low participation rate (14%). Incentive might be necessary to improve participation rate and data collection methods must also be simplified. A 24-h recall plus a 1-day diary seem sufficient and data on consumption could be limited to liquids, soups and cereals.
Etude épidémiologique/ Consommation d'eau / Humain / Age. Etude à visée épidémiologique pour connaître par enquête de consommation le comportement dipsique de sujets (n=125) en milieu urbain (nature, quantité, lieu de consommation).832 - Response To Dehydration In Elderly Patients In Long-term Care.
Elderly patients in long-term care have a high plasma osmolality (pOSM) and associated increased mortality. In these patients, we examined pOSM, thirst (visual analogue scale, VAS) and arginine vasopressin (AVP) response to 16-hour dehydration and 2-hour rehydration. Twelve patients were randomly divided into two groups (A & B). Group A had their fluid balance monitored for two weeks, group B did not. Single measurements of VAS, pOSM and AVP were conducted on days 0, 7 and 13. Dehydration tests were conducted in both groups at the start of the study (DAY 1), and at the end of the two-week period (DAY 14). There were no significant differences between group A and B, so the results are presented for the two groups combined. There was a significant increase in both pOSM and VAS during dehydration, and a significant fall in both variables during rehydration (F (9,99) = 18.69, p < 0.001, and F(9,99) = 11.25, p < 0.001, respectively). Plasma AVP did not change significantly during either dehydration or rehydration (F (9,99) = 0.59, p = 0.8). There were no significant differences in response for any of the three variables between DAY 1 and DAY 14. We conclude that elderly patients in long-term care exhibit changes in thirst and osmolality during dehydration and rehydration, and that these responses are reproducible. The lack of a significant AVP response requires further investigation.
Modification de la soif chez les personnes âgées vivant en long séjour.833 - Water Supplementation Enhances The Effect Of High-fiber Diet On Stool Frequency And Laxative Consumption In Adult Patients With Functional Constipation.
BACKGROUND/AIMS:
The purpose of this study was to determine the effects of a high-fiber diet and fluid supplementation in patients with functional chronic constipation
METHODOLOGY:
One hundred and seventeen patients with chronic functional constipation (aged 18-50 years) were randomly divided into two treatment groups. For two months both groups consumed a standard diet providing approximately 25 g fiber per day. Group 1 (58 patients) was allowed ad libitum fluid intake, while Group 2 was instructed to drink 2 liters of mineral water per day Compliance was monitored throughout the study and results were assessed in terms of bowel-movement frequency and laxative use.
RESULTS:
Fiber intake was similar in the two groups, while total daily fluid intake in Group 2 (mean 2.1 liters) was significantly greater than that of Group 1 (1.1 liters) (p < 0.001). In both groups, there were statistically significant increases in stool frequency and decreases in laxative use during the two-month trial, but both changes were greater in Group 2 (stool frequency: p < 0.001 vs. Group 1/ laxative use: p < 0.001 vs Group 1).
CONCLUSION:
A daily fiber intake of 25 g can increase stool frequency in patients with chronic functional constipation, and this effect can be significantly enhanced by increasing fluid intake to 1.5-2.0 liters /day.
Effet favorable pour lutter contre la constipation d'associer à une supplémentation en fibres, un apport liquidien augmenté. 834 - Prevention Of Early Childhood Caries.
This paper reviews the methods used for the prevention of earlychildhood caries (ECC). The education of mothers or caregivers to promote healthy dietary habits in infants has been the main strategy used for the prevention of ECC. This review found that education has a modest impact on the development of ECC. While education should be promoted especially in high risk communities and population groups (low-income families and native populations), it should not be the only preventive strategy of ECC. Early screening for signs of caries development, starting from the first year of life, could identify infants and toddlers who are at risk of developing ECC and assist in providing information to parents about how to promote oral health and prevent the development of tooth decay. High risk children include those with early signs of ECC, poor oral hygiene, limited exposure to fluorides, and frequent exposure to sugary snacks and drinks. These children should be targeted with a professional preventive program that includes fluoride varnish application, fluoridated dentifrices, fluoride supplements, sealants, diet counseling, and chlorhexidine. Prevention of ECC also requires addressing the social and economic factors that face many families where ECC is endemic.
Pour la prévention précoce de la carie, les méthodes doivent d'abord aborder la recherche des signes les plus précoces. Les programmes de prévention font appel aux applications de vernis fluorés, de dentifrices, de la supplémentation de fluor dans l'eau, dans le sel, des conseils diététiques et de la Chlorexidine. Le rôle des facteurs sociaux et économiques dans les zones d'endémie, doit être souligné. Bonne revue sur les méthodes de prévention.835 - Genetics, Calcium Intake And Osteoporosis.
Genetic factors explain a high proportion of the age-specificdifferences in bone density, size and turnover. The potential for interaction between hormonal, diet and lifestyle factors is likely to be important. Common allelic variation in the VDR is an example of normal gene variants altering Ca homoeostasis, with effects on body and bone size as well as bone density. The VDR findings suggesting interactions between genetic and nutritional factors are an important target for future research. These studies are complicated by the potential for effects of gene-gene interactions and of undefined environmental factors. These problems notwithstanding, considerations of environmental and nutritional contributions, such as Ca intake and vitamin D status, will be critical in interpreting these genetic pathways and in ''personalizing'' nutritional recommendations.
Etude des interactions entre les facteurs génétiques et les facteurs nutritionnels. Peu d'incidence pratique à ce jour.