Biomedical subjects

S Hercberg

Publications and source records attributed to S Hercberg.

At least 55 records · Page 3Linked to original sources

PubMed2001

Use of 'light' foods and drinks in French adults: biological, anthropometric and nutritional correlates.

BACKGROUND: A population of over 12,000 mature subjects participated in a longitudinal study (8 years) of nutrition and health (the Su.Vi.Max Study). In this context, a specific cross-sectional study was carried out in a randomly selected subpopulation. AIM: To identify anthropometric, nutritional and biochemical correlates of spontaneous use of 'light' foods and drinks in a free-living population. DESIGN: Men (n = 2299) and women (n = 1979), 45-60 years, reported their food intakes over six non-consecutive days. Consumers of low-fat and low-sugar foods and drinks, and artificial sweeteners, were compared with non-consumers. RESULTS: Users of low-sugar products were heavier than non-users; female consumers of low-fat products, but not males, had higher body weight and BMI than non-consumers. Users of low-sugar products had higher triacylglycerols and glycaemia than non-users while biochemical parameters were not different in users and non-users of low-fat products. Use of low-sugar products led to increased diet density of a few micronutrients, including cholesterol. Low-fat product selection was associated with increased intake of most micronutrients, both in absolute value and in density. CONCLUSIONS: In mature adults, selection of fat-reduced products was associated with improved quality of the diet, while anthropometric and biological parameters appeared less favourable in consumers of low-sugar products vs. non-consumers. The longitudinal follow-up of the cohort in future years will help determine cause-and-effect relationships among these parameters.

Adult↗

PubMed2001

Iron deficiency in Europe.

In Europe, iron deficiency is considered to be one of the main nutritional deficiency disorders affecting large fractions of the population, particularly such physiological groups as children, menstruating women and pregnant women. Some factors such as type of contraception in women, blood donation or minor pathological blood loss (haemorrhoids, gynaecological bleeding...) considerably increase the difficulty of covering iron needs. Moreover, women, especially adolescents consuming low-energy diets, vegetarians and vegans are at high risk of iron deficiency. Although there is no evidence that an absence of iron stores has any adverse consequences, it does indicate that iron nutrition is borderline, since any further reduction in body iron is associated with a decrease in the level of functional compounds such as haemoglobin. The prevalence of iron-deficient anaemia has slightly decreased in infants and menstruating women. Some positive factors may have contributed to reducing the prevalence of iron-deficiency anaemia in some groups of population: the use of iron-fortified formulas and iron-fortified cereals; the use of oral contraceptives and increased enrichment of iron in several countries; and the use of iron supplements during pregnancy in some European countries. It is possible to prevent and control iron deficiency by counseling individuals and families about sound iron nutrition during infancy and beyond, and about iron supplementation during pregnancy, by screening persons on the basis of their risk for iron deficiency, and by treating and following up persons with presumptive iron deficiency. This may help to reduce manifestations of iron deficiency and thus improve public health. Evidence linking iron status with risk of cardiovascular disease or cancer is unconvincing and does not justify changes in food fortification or medical practice, particularly because the benefits of assuring adequate iron intake during growth and development are well established. But stronger evidence is needed before rejecting the hypothesis that greater iron stores increase the incidence of CVD or cancer. At present, currently available data do not support radical changes in dietary recommendations. They include all means for increasing the content of dietary factors enhancing iron absorption or reducing the content of factors inhibiting iron absorption. Increased knowledge and increased information about factors may be important tools in the prevention of iron deficiency in Europe.

Adolescent↗

PubMed2001

Interventional studies concerning the role of antioxidant vitamins in cardiovascular diseases: a review.

Cardiovascular diseases continue to constitute a major public health problem in all industrialized countries, where they are the main causes of premature mortality. There is a large body of evidence suggesting that free radical production directly or indirectly plays a major role in cellular processes implicated in atherosclerosis. Here we present mechanistic data and results of epidemiologic studies on the relationship between antioxidant vitamin intake or biochemical status and the risk of cardiovascular diseases. Most epidemiologic data obtained on this topic have been based on observational approaches, i.e. ecological studies, case-control or prospective studies. All these studies indicate that a high dietary intake or high blood concentrations of antioxidant vitamins are associated with a reduced risk of cardiovascular diseases. Although the results of these studies are convergent, they merely suggest a relationship at the population and individual level, but do not affirm a causality link. Only intervention studies (randomized trials), by specifically changing antioxidant vitamin intake, can provide conclusive answers. The apparent discrepancies between the results of recently published trials may be explained by the type of population (general or high-risk subjects), the differing doses of supplementation (nutritional levels or higher), the number of antioxidants tested (one, two or more) and the type of administration (alone or in balanced association). It thus appears that low risk of pathologies may be related to multiple nutrients consumed, at nutritional doses, and in combination. Optimal effects may be expected with a combination of nutrients at levels similar to those found in a healthy diet. A single antioxidant vitamin given at high doses in subjects with high risk of pathologies may not have substantial benefits and could even have negative consequences.

Antioxidants↗

PubMed2001

Effect of two years' supplementation with natural antioxidants on vitamin and trace element status biomarkers: preliminary data of the SU.VI.MAX study.

The "SUpplementation en VItamines et Minéraux AntioXidants" (SU.VI.MAX) study is a randomized double-blind, placebo controlled, primary-prevention trial designed to test the efficacy of a daily supplementation with antioxidant vitamins (vitamin C, 120 mg; vitamin E, 30 mg; and beta-carotene, 6 mg) and minerals (selenium, 100 microg; and zinc, 20 mg) at nutritional doses (one to three times the daily recommended dietary allowances), in reducing the frequency of cancers and cardiovascular diseases. The study involves 12,735 eligible subjects (women aged 35-60 years, men aged 45-60 years) included in 1994 in France. They will be followed up for 8 years. The targeted population is the general population. The aim of this specific analysis is to assess the effect of 2 years of supplementation on biochemical indicators of vitamin and trace element on a subsample of 1000 subjects. The mean (+/- standard deviation) concentrations of plasma beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc among participants who were randomly assigned to receive a daily supplementation with beta-carotene, vitamin E, vitamin C, selenium and zinc for 2 years were significantly higher than those who were assigned to receive placebo. Specifically, the mean concentrations among men in the intervention group were 0.86 +/- 0.70 micromol/L for beta-carotene, 35.3 +/- 9.3 micromol/L for alpha-tocopherol, 11.5 +/- 4.7 microg/ mL for vitamin C, 1.65 +/- 0.33 micromol/L for selenium, and 16.2 +/- 3.9 micromol/L for zinc. The mean concentrations among women in the intervention were 1.25 +/- 0.90 micromol/L for beta-carotene, 34.9 +/- 8.4 micromol/L for alpha-tocopherol, 12.6 +/- 4.0 microg/mL for vitamin C, 1.68 +/- 0.37 micromol/L for selenium, and 15.3 +/- 3.9 micromol/L for zinc. The values observed for beta-carotene and vitamin E in the supplementation group after 2 years of intervention are those that have been associated with the lowest risk of cancer in observational studies. They are definitely lower than concentrations reported in intervention studies showing an apparent negative effect of high levels of beta-carotene supplementation on the lung cancer incidence rate in high-risk subjects (initial level multiplied by 12-18). Data from the follow-up will ascertain if any plausible reduction in the incidence rate of cancers may be associated with such amounts of antioxidant agents.

Adult↗

PubMed2001

[Ultrasonic assessment of thyroid nodules, and iodine status of French adults participating in the SU.VI.MAX study].

Thyroid nodules were assessed by ultrasound in 3 621 presumably healthy free-living French subjects participating in the SU.VI.MAX cohort (2 160 females aged 35-60 years and 1 461 males aged 45-60 years). Urinary iodine was measured in all participants in random morning urine samples. Nodular thyroid structures ranging from 3 mm to 57 mm in diameter were found in 14.5% of the population, without significant differences between regions in the different age and sex groups. Single nodules and multiple lesions were found in, respectively, 9.7% and 3.1% of the subjects. In females, nodules increased from 12.9% to 19.2% between 35-45 years and 45-60 years, respectively (p<0.001). Thyroid nodularity was more frequent among women aged 45-60 years than among men of those ages (19.2% vs. 11.0%, p=0.001). Descriptive data provided by ultrasound differentiated the nodules into solid (43.4%), cystic (38.4%), and mixed solid-cystic (18.2%). Most solid thyroid nodules, 76.1%, were hypoechoic, while 16.6% were iso-, and 7.3% were hyperechoic. The median of iodine concentrations (n=3 276) was 8.0 microgram/100 ml, with 19.4% of the samples being<5 microgram/100 ml. Median iodine concentrations displayed wide regional variations, with values significantly higher in residents of western regions than among those living in the eastern areas (p<0.001), independently of age and sex. No relationship was found between prevalence of nodular thyroid structure and the state of borderline iodine status observed in France.

Adult↗

PubMed2000

[Epidemiology of iron deficiency].

During the last years, a large number of surveys have suggested than some fractions of the French population, as in other industrialized countries, presented dietary iron intake below the recommended dietary allowances. Iron deficiency is widespread in children, menstruating women, and particularly pregnant women. Iron deficiency is enough severe to be responsible of anemia in some groups of population. Aside the classical risk of anemia (with its well-known consequences on health), the effects of iron deficiency by itself, taking into consideration the role of iron in numerous metabolic functions, needs to be more documented to assess the potential deleterious consequences upon health.

Adolescent↗

PubMed2000

Epidemiologic determinants of skin photoaging: baseline data of the SU.VI.MAX. cohort.

BACKGROUND: Although skin disorders associated with long-term sun exposure account for high morbidity, only few data on sun-related preclinical skin changes are available in the general population. OBJECTIVE: In the present study we determined reference values for markers of photoaging in French adults, and we evaluated the relationship between photoaging, phototype, and both behavioral and environmental factors. METHODS: The SU.VI.MAX trial is a multicenter, national intervention trial on 12,735 adults living in France. A transverse analysis was performed on the inclusion data of the sample of volunteers between 45 and 60 years of age who underwent skin evaluation in 1995: 3057 women and 3606 men. Skin was evaluated by means of the Larnier skin photoaging photographic scale and a sun reactive skin type classification derived from those proposed by Fitzpatrick in 1976 and Césarini in 1977. RESULTS: The prevalence of skin photoaging, assessed as a dichotomous variable (from moderate/severe to very severe), was comparable in men and women in same age groups: in women, age group 45-49 years = 22%, 50-54 years = 36%, and 55-60 years = 42%; in men, age group 45-49 years = 17%, 50-54 years = 38%, and 55-60 years = 45%. After adjusting for body mass index, exposure to tobacco, and sunlight exposure, the only variables found to be related to skin photoaging in women were age (55-60 years age group: adjusted odds ratio [AOR] = 6.0, 95% confidence interval [CI] = 4.4-8.2), phototype IIIa, IIIb, and IV (AOR = 0.2, 95% CI = 0.1-0.4; AOR = 0.3, 95% CI = 0.2-0.6; and AOR = 0.4, 95% CI = 0.3-0.8; respectively), menopausal status (AOR = 1.4, 95% CI = 1.1-1.9), and geographic location (Southern France: AOR = 0. 7, 95% CI = 0.6-0.9), with a more pronounced effect in lighter phototypes I-II and a protective impact related to southern locations. No relationship was found between the use of oral contraceptives and skin photoaging. The age effect was also found in men (55-60 years age group: AOR = 10.4, 95% CI = 8.3-13.1) and geographic location (Southern France: AOR = 0.8, 95% CI = 0.6-0.9), with a most pronounced effect in darker phototypes (phototypes > IV: AOR = 2.8, 95% CI = 1.4-5.6). CONCLUSION: Our results suggest that the prevalence of skin photoaging in the adult French population is determined by age, sex, geographic location, and phototype. The continuation of this longitudinal study will allow for the investigation of the relationship between skin photoaging and the risk of the development of skin diseases.

Female↗

PubMed2000

Factors determining the use of hormone replacement therapy in recent naturally postmenopausal women participating in the French SU.VI.MAX cohort.

The determinants of hormone replacement therapy (HRT) were studied in a cohort of recently postmenopausal women participating, in France, in a nutritional study (SU.VI.MAX Study). Analysis was performed-analysis on 592 women aged 45 years or more, who had undergone natural menopause which appeared in the 2 previous years. No differences were observed in education level, socio-professional categories, marital status, geographic residence, smoking habits, physical activity, or past contraceptive practice. Past regular gynecologic follow-up appeared to be the strongest determinant of HRT use (odds ratio [OR]: 3.18). Women who reported having had at least one of the studied pathologies (past history of breast cancer, phlebitis, anger, uterine fibroma, hypertension, diabetes or hypercholesterolemia), past abundant menstrual blood losses, and with body mass index (BMI) > or = 25 were less likely to be taking HRT than women free of pathology, with no history of past abundant menstrual blood losses and with low BMI (OR respectively of 0.40, 0.64, 0.62). Women over 51.3 years of age were less likely to use HRT than younger women (OR: 0.92). Finally, in our population, while socio-economic level was not a major determinant of HRT use, the regularity of gynecological follow-up before menopause, overweight, and the existence of a definite or possible contra-indication were strong determinants of HRT use.

Age Factors↗

PubMed2000

Effect of daily iron supplementation on iron status, cell-mediated immunity, and incidence of infections in 6-36 month old Togolese children.

OBJECTIVE: To assess the impact of a daily oral iron supplementation on hematological status, cell-mediated immunity and susceptibility to infections in children living in an environment where iron deficiency, malaria and other infections are frequent. DESIGN: Randomized, double-blind iron supplementation including a placebo group. SETTING: A village in Togo, West Africa. SUBJECTS: Of the 229 6-36-month-old children of both sexes recruited, 197 with hemoglobin concentration >/=80 g/l were included and 163 completed the study. INTERVENTION: Children received daily a placebo (n=79) or a dose of 2-3 mg of elemental iron per kg of body weight (n=84) for 3 months. Hematological, nutritional and immune status were assessed at the beginning and at the end of the supplementation period, and 6 months later. Morbidity was recorded throughout the study. RESULTS: Iron supplementation had a significant and positive effect on iron status of children and no impact on the incidence of infections, especially malaria. Its probable effect on immune status was masked by interference of infections and their treatment, which contributed to improve hematological and immune status in both groups. CONCLUSION: According to the negative consequences of anemia and iron deficiency on global child development, control of iron deficiency by oral iron supplementation in young children has to be conducted, associated with prophylaxis and treatment of malaria and repeated deworming. SPONSORSHIP: Program supported by IRD. European Journal of Clinical Nutrition (2000) 54, 29-35

Analysis of Variance↗

PubMed2000

Dietary patterns in six european populations: results from EURALIM, a collaborative European data harmonization and information campaign.

OBJECTIVE: To determine and describe the extent to which European dietary data collected in disparate surveys can be meaningfully compared. DESIGN: Seven independent population-based surveys from six European countries were initially included. Differences in study designs and methodological approaches were examined. Risk factor data for 31,289 adults aged 40-59 y were harmonized and pooled in a common, centralized database. RESULTS: Direct comparisons of dietary measures across studies were not deemed appropriate due to methodological heterogeneity. Nonetheless, comparisons of intra-population contrasts by gender across sites were considered valid. Women consumed fruit and vegetables more often than men. Age-standardized gender differences in the prevalence of low fruit and vegetable consumption ranged from 7 to 18% and 5 to 15%, respectively. Data on energy intake showed good agreement across study populations. The proportion of total energy from macronutrients was similar for women and men. Gender differences for relative intakes of saturated fatty acids (percentage energy) were small and only in France were they significant. Dietary fibre density was significantly higher in women than in men. Overall, the participating Southern European populations from Italy and Spain exhibited more healthful food composition patterns. CONCLUSIONS: Contrasts in dietary patterns by gender across populations may provide the basis for health promotion campaigns. The most favourable patterns observed may serve as attainable goals for other populations. An international risk factor surveillance programme based upon locally run, good quality studies has the potential to provide the needed data. SPONSORSHIP: European Community (DG V), project 96CVVF3-446-0; Swiss Federal Office for Education and Science, OFES 96.0089.

Adult↗

PubMed2000

The Pro115Gln and Pro12Ala PPAR gamma gene mutations in obesity and type 2 diabetes.

OBJECTIVE: Peroxisome-proliferator-activated receptors gamma (PPAR gamma), is a key regulator of adipocyte differentiation and energy balance. Two naturally occurring mutations in the PPAR gamma gene, Pro115Gln and Pro12Ala, have recently been shown to impair the function of the PPAR gamma2 isoform of the receptor and to be associated with obesity or diabetes-related phenotypes in different populations. SUBJECTS: We studied the occurrence and possible associations of the Pro115Gln and Pro12Ala in the PPAR gamma2 gene with several clinical and metabolic phenotypes in three independent large populations of non-obese non-diabetic, type 2 diabetic, and morbidly obese French Caucasians. RESULTS: The Pro115Gln mutation was not found in any of the 1069 subjects screened including 626 obese patients. The frequency of the Pro12Ala mutation was similar in all groups (0.08, 0.11, 0.09) and was not associated with BMI or any of the clinical parameters tested. CONCLUSIONS: We conclude that the Pro115Gln mutation is not a frequent cause of morbid obesity in Caucasians and that the Pro12Ala mutation is not associated with clinically significant changes in these populations.

Adult↗

PubMed2000

Determinants of thyroid volume in healthy French adults participating in the SU.VI.MAX cohort.

OBJECTIVE: To study the relative importance of determinants of thyroid volume. DESIGN: Cross-sectional study on a sample of subjects issued from the SU.VI.MAX cohort. SUBJECTS: 2987 French subjects (1713 women aged 35-60 years and 1274 men aged 45-60 years). None of them had previous or present thyroid disease. MEASUREMENTS: Thyroid volume was determined by ultrasound. Serum TSH and free thyroxine (fT4) were measured in duplicate. Urinary iodine and urinary thiocyanate were assayed in random morning urine samples. RESULTS: For both sexes, thyroid volume (ml) was positively correlated with weight, height, body mass index and body surface area (P = 0.0001) and negatively with age for females (P = 0.0009). When the urinary iodine concentration was adjusted for urinary thiocyanate concentration and their interaction, the thyroid volume was negatively correlated with urinary iodine (males P = 0.02, females P = 0.006) and positively correlated with urinary thiocyanate (males P = 0.0001, females P = 0.004). Mean thyroid volume was greater among active smokers than non-smokers (males P < 0.0001, females P = 0.0004) and was greater among former smokers than among non-smokers (males P = 0.0001, females = 0.004). Free T4 and thyroid volume were positively correlated for both sexes (P = 0. 0001). TSH was negatively correlated with thyroid volume for both groups (P = 0.0001). Female users of oral contraception (aged 35-45 years) had a smaller thyroid volume than non-users (P = 0.0009). CONCLUSIONS: The state of borderline iodine deficiency observed in France, in association with a slightly goitrogenic environment, may result in sustained stimulation of the thyroid, independently of TSH level, and is of paramount importance in the formation of goitre. Smoking may affect the thyroid, inducing marked long-lasting thyroid enlargement.

Adult↗

PubMed2000

Self-administered questionnaire compared with interview to assess past-year physical activity.

PURPOSE: The Modifiable Activity Questionnaire (MAQ) is a physical activity questionnaire shown to be both valid and reliable and was initially designed to be interviewer-administered. After translation and adaptation into French, the objective of the study was to compare past-year physical activity data obtained by self-administration of this questionnaire and by interviewer-administration. METHODS: 84 subjects (22 men, 62 women, age 36-63 yr) enrolled in an ongoing prospective study in France (the SUpplementation en VItamines et Minéraux AntioXydants or SU.VI.MAX study) completed both versions of the questionnaire in a randomized order with a mean (SD) delay of 7.9 (5.8) d between the two modes. Past-year leisure and occupational physical activity were expressed as both h x wk(-1) and MET-h x wk(-1) of activity, and television watching was expressed as h x d(-1). Analysis of variance on ranks was used to compare activity variables obtained by self-administration and interview. Agreement was assessed by nonparametric intraclass correlation coefficients. RESULTS: A significant effect of the mode of administration was found only for past-year leisure physical activity with lower values reported in self-administered conditions compared with interview. However, a high level of concordance between the two modes of administration was observed for all variables as shown by the intraclass correlation coefficients: 0.90 for leisure physical activity (h x wk(-1)), 0.82 for occupational activity (h x wk(-1)), 0.83 for total (leisure and occupational combined) physical activity (h x wk(-1)), and 0.97 for television viewing (h x d(-1)). CONCLUSIONS: The agreement between the two modes of administration of the questionnaire suggests that the self-administered version of the MAQ is a valuable tool to assess past-year physical activity and inactivity in self-administered conditions. This instrument could be used in large-scale population studies investigating the relationships between physical activity and health outcomes.

Adult↗

PubMed2000

Obesity and other health determinants across Europe: the EURALIM project.

STUDY OBJECTIVE: EURALIM (EURope ALIMentation), a European collaborative study, aimed to determine and describe the extent to which European data on risk factor distributions from different populations could be pooled and harmonised in a common database for international comparisons. SETTING: Seven independent population-based surveys from six European countries (France, Italy, Northern Ireland/United Kingdom, Spain, Switzerland, the Netherlands). METHODS: Data for 18 381 women and 12 908 men aged 40-59 were pooled in a common database. Central statistical analyses on major cardiovascular risk factors were conducted with careful consideration of methodological issues, including differences in study designs, data assessment tools, and analytic techniques used. MAIN RESULTS: Because of the detected variability among methods used, direct comparisons of risk factor distributions and prevalences between studies were problematic. None the less, comparisons of within population contrasts by sex, age group, and other health determinants were considered to be meaningful and apt, as illustrated here for obesity. Results were targeted and disseminated to both the general public and public health professionals and framed in the context of a European information campaign. CONCLUSIONS: International and national comparisons between existing locally run studies are feasible and useful, but harmonisation methods need improvement. Development of an international risk factor surveillance programme based on decentralised data collection is warranted. In the meantime, risk factor contrasts across populations can be used as a basis for targeting needed public health intervention programmes.

Adult↗

PubMed2000

Contribution of ready-to-eat cereals to nutrition intakes in French adults and relations with corpulence.

AIMS: The nutrient impact of ready-to-eat (RTE) cereal consumption was assessed in adults (men 45-60 years; women 35-60 years old) who regularly consumed RTE cereals anytime during the day, compared to those who did not or who were occasional eaters. METHODS: Data were obtained for 2,188 men and 2,851 women living in France and participating in the SU.VI.MAX cohort, who reported twelve 24-hour dietary records during 2 years of follow-up (60,468 records). RESULTS: In the heavy consumers group, RTE cereals provided 193 kcal/day for men and 168 kcal/day for women and contributed 8-10% of total daily energy intake; 15-17% of total daily carbohydrates intake; 4% of total daily lipids intake; 5-6% of total protein intake; and 19-23% of total fiber intake. Moreover, RTE cereals contributed 20-30% of total daily intake for vitamins B1, B2, B6 and folic acid, and 7% for vitamin B12. For minerals, they provided, respectively, for men and women, 22 and 25% of total daily intake for iron, 12 and 14% for magnesium, and 4% for calcium. In both genders, heavy consumers of RTE cereals derived a greater proportion of daily energy from carbohydrates and a lesser proportion of energy from fats. Total daily fiber intake is higher for RTE cereal consumers than for nonconsumers and increases with the frequency of consumption. Frequent consumers of RTE cereals have higher dietary intakes of calcium, magnesium, iron, vitamins B1, B2, B6, and folic acid than do nonconsumers. BMI and waist/hip ratio were significantly lower in heavy consumers of RTE cereals than in nonconsumers. CONCLUSIONS: The present data suggest that the consumption of RTE cereals contributes to a balanced diet. The strong association between cereal consumption and vitamin and mineral intakes confirm previous studies suggesting that RTE cereals make a major contribution to micronutrient intakes. The consumption of RTE cereals also appears to be associated with lower corpulence.

Adult↗

PubMed2000

Melanocortin-4 receptor mutations are a frequent and heterogeneous cause of morbid obesity.

By integrating an agonist satiety signal, provided by alpha-melanocyte-stimulating hormone (alpha-MSH), and an antagonist signal, provided by agouti-related protein (AGRP), the melanocortin-4 receptor (MC4-R) is a key element in the hypothalamic control of food intake. Inactivation of the gene encoding this G protein-coupled receptor causes obesity in mice. In humans, frameshift mutations in MC4-R cause an early-onset dominant form of obesity in two families. In this study we find a high frequency (4%) of rare heterozygous MC4-R mutations in a large population of morbidly obese patients. No such mutations were found in controls. By analyzing the phenotypes of the probands carrying these mutations, we demonstrate that these patients display a common, nonsyndromic form of obesity. Interestingly, functional analysis of the mutant receptors indicates that obesity-associated defects in MC4-R range from loss of function to constitutive activation. Transmission of these mutations in the families of the carriers indicates a variable expressivity that is not related to the functional severity of the mutations. This variable expressivity of MC4-R-associated obesity is not due to variations in genes for alpha-MSH or AGRP. Taken together, these results demonstrate that MC4-R mutations are a frequent but heterogeneous genetic cause of morbid obesity.

Adolescent↗

PubMed2000

Relationship between vitamin D status and skin phototype in general adult population.

A link between bone mineral density and skin color has been reported recently, and pigmentation has been shown to affect cutaneous vitamin D production. In the present study, we investigated the relationship between phototype, global self-assessed sun exposure, geographical location and vitamin D serum levels in 1191 French adults. When the factors were analyzed separately, individuals with lower phototypes as well as those with lower sun exposure showed significantly lower levels of vitamin D than those with darker phototypes or those with higher sun exposure. However, when factors were analyzed as a whole, the vitamin D status was no longer linked with the phototype, but with sun exposure and geographical location. Since phototypes and global self-assessments of sun exposure were positively linked, our data suggest that lower vitamin D levels in fair-skinned individuals are due to their sun exposure behavior.

Adult↗

PubMed2000

[Nitrogen dioxide and ozone exposures in a population sample from Ile-de-France].

BACKGROUND: Individual exposure to NO(2)and O(3) has been estimated in an urban population sample in southern France and the determinants identified. The present study was conducted to evaluated individual exposure to NO(2) and O(3) and to identify the environmental determinants of exposure in a larger population living in different environmental conditions. METHODS: Two hundred ninety-four volunteers were recruited from the SUVIMAX sample in Ile-de-France. The study covered 2 periods of 5 consecutive days, one in winter and the other in the fall of 1998. Passive monitors were used to estimate individual exposure and indoor concentration at the participant's dwelling. Background atmosphere concentrations were obtained for the AIRPARIF surveillance network. Single and multiple ANOVA were used for statistical analysis. RESULTS: Individual exposures were low, especially for O(3) in the considered periods of time. Mean NO(2) and O(3)concentrations were 41 microg/m(3)/h and 16 microg/m(3)/h, respectively. The NO(2) individual exposure increased with the time spent in traffic and indoor concentration. The correlation coefficient between indoor and individual levels was r=0.73, and indoor concentration explained 50% of the variance in individual exposure. The site of the dwelling with regard to high traffic street, and most strongly, the presence of a gas stove influenced indoor concentration. However, mechanical air extraction decreased the mean indoor NO(2) level of the dwellings. CONCLUSION: This study allowed identification of the environmental determinants of NO(2) exposure in an urban sample. These data, together with those obtained previously, well be used to establish an exposure matrix for NO(2).

Air Pollutants↗