Toxicants can cross the placenta and expose the developing fetus to chemical contamination leading to possible adverse health effects, by potentially inducing alterations in immune competence. Our aim was to investigate the impacts of maternal exposure to air pollution before and during pregnancy on newborn's immune system.
Exposure to background particulate matter less than 10 μm in diameter (PM10) and nitrogen dioxide (NO2) was assessed in 370 women three months before and during pregnancy using monitoring stations. Personal exposure to four volatile organic compounds (VOCs) was measured in a subsample of 56 non-smoking women with a diffusive air sampler during the second trimester of pregnancy. Cord blood was analyzed at birth by multi-parameter flow cytometry to determine lymphocyte subsets.
Among other immunophenotypic changes in cord blood, decreases in the CD4+CD25+ T-cell percentage of 0.82% (p = 0.01), 0.71% (p = 0.04), 0.88% (p = 0.02), and 0.59% (p = 0.04) for a 10 μg/m3 increase in PM10 levels three months before and during the first, second and third trimester of pregnancy, respectively, were observed after adjusting for confounders. A similar decrease in CD4+CD25+ T-cell percentage was observed in association with personal exposure to benzene. A similar trend was observed between NO2 exposure and CD4+CD25+ T-cell percentage; however the association was stronger between NO2 exposure and an increased percentage of CD8+ T-cells.
These data suggest that maternal exposure to air pollution before and during pregnancy may alter the immune competence in offspring thus increasing the child's risk of developing health conditions later in life, including asthma and allergies.
The use of structural equation modeling and latent variables remains uncommon in epidemiology despite its potential usefulness. The latter was illustrated by studying cross-sectional and longitudinal relationships between eating behavior and adiposity, using four different indicators of fat mass.
Using data from a longitudinal community-based study, we fitted structural equation models including two latent variables (respectively baseline adiposity and adiposity change after 2 years of follow-up), each being defined, by the four following anthropometric measurement (respectively by their changes): body mass index, waist circumference, skinfold thickness and percent body fat. Latent adiposity variables were hypothesized to depend on a cognitive restraint score, calculated from answers to an eating-behavior questionnaire (TFEQ-18), either cross-sectionally or longitudinally.
We found that high baseline adiposity was associated with a 2-year increase of the cognitive restraint score and no convincing relationship between baseline cognitive restraint and 2-year adiposity change could be established.
The latent variable modeling approach enabled presentation of synthetic results rather than separate regression models and detailed analysis of the causal effects of interest. In the general population, restrained eating appears to be an adaptive response of subjects prone to gaining weight more than as a risk factor for fat-mass increase.
To study the relationship between pre-pregnancy body mass index (BMI) and weight gain during pregnancy with pregnancy and birth outcomes, with a focus on gestational diabetes and hypertension and their role in the association with fetal growth.
We studied 1884 mothers and offspring from the Eden mother-child cohort. Weight before pregnancy (W1) and weight after delivery (W2) were collected and we calculated BMI and net gestational weight gain (netGWG=(W2−W1)/(weeks of gestation)). Gestational diabetes, hypertension gestational age and birth weight were collected. We used multivariate linear or logistic models to study the association between BMI, netGWG and pregnancy and birth outcomes, adjusting for center, maternal age and height, parity and average number of cigarettes smoked per day during pregnancy.
High BMI was more strongly related to the risk of giving birth to a large-for-gestational-age (LGA) baby than high netGWG (odds ratio OR [95% CI] of 3.23 [1.86–5.60] and 1.61 [0.91–2.85] respectively). However, after excluding mothers with gestational diabetes or hypertension the ORs for LGA respectively weakened (OR 2.57 [1.29–5.13]) for obese women and strengthened for high netGWG (OR 2.08 [1.14–3.80]). Low in comparison to normal netGWG had an OR of 2.18 [1.20–3.99] for pre-term birth, which became stronger after accounting for blood pressure and glucose disorders (OR 2.70 [1.37–5.34]).
Higher net gestational weight gain was significantly associated with an increased risk of LGA only after accounting for blood pressure and glucose disorders. High gestational weight gain should not be neglected in regard to risk of LGA in women without apparent risk factors.
Adult; Birth Weight; physiology; Body Mass Index; Diabetes, Gestational; epidemiology; Female; Fetal Macrosomia; etiology; Gestational Age; Humans; Hypertension, Pregnancy-Induced; epidemiology; Infant; Maternal Age; Obesity; complications; Pregnancy; Pregnancy Outcome; Risk Factors; Weight Gain; physiology; obesity; pregnancy; gestational diabetes; hypertension; birth weight
Etude Longitudinale Française depuis l'Enfance (ELFE) will be a national French cohort of 20,000 children followed from birth to adulthood. Biological samples will be taken at birth to evaluate the fetal exposition to several substances. A pilot study was carried out in October 2007 to test the preanalytical factors that affected sample quality. A variety of fractions were collected by the midwife after delivery from different blood collection tubes. Options in the collection process were 2 daily transports of samples, centralized and standardized processing methodology, and storage of multiple aliquots in liquid nitrogen or at −80°C. We analyzed preanalytical factors that could have affected coagulation and then soluble CD40 Ligand (sCD40L) as a quality control tool for serum quality. Cord blood and urine were collected from 82% and 84% of women, respectively, who agreed to be followed up in the ELFE project. The use of syringe was the main factor correlated with coagulation (relative risk: 2.79 [1.47; 5.31], P<0.01). Maternity unit status was also associated with coagulation (RR: 1.48 [1.03; 2.13] in a private maternity unit vs. a public maternity) as well as time between collection and centrifugation (RR 1.03 [1; 1.07] when time between collection and centrifugation increases from 1 h). There were no extremely low sCD40L values indicating extreme exposures to room temperatures. This first evaluation study allowed us to stress the importance of carefully recording all potentially critical preanalytical variables that might be used at a large-scale level.
To understand the relationships between maternal glycemia during pregnancy and prenatal and early postnatal growth by evaluating cord C-peptide and IGF-I as mediating biomarkers in boys and girls separately.
RESEARCH DESIGN AND METHODS
We evaluated 342 neonates within the EDEN mother-child cohort study born to mothers without diabetes diagnosis before pregnancy. We measured maternal glycemia at 24–28 weeks of gestation and neonates’ cord blood C-peptide (used as a proxy for fetal insulin) and IGF-I at birth. Reported maternal prepregnancy BMI and all measured infant weights and lengths in the 1st year were recorded. Growth modeling was used to obtain an individual growth curve for each infant in the 1st year. Path models, a type of structural equation modeling, were used for statistical analysis. Path analysis is a multivariate method associated with a graphical display that allows evaluation of mediating factors and distinguishes direct, indirect, and total effects.
Cord C-peptide at birth was positively correlated with maternal prepregnancy BMI and maternal glycemia and was higher in girls. In a path model that represented prenatal growth, there was no significant direct effect of maternal glycemia on birth weight, but the effect of maternal glycemia on birth weight was mediated by fetal insulin and IGF-I in both girls and boys. However, in girls only, higher concentrations of cord C-peptide (but not cord IGF-I or maternal glucose) were associated with slower weight growth in the first 3 months of life.
Our study underlines the role of the fetal insulin–IGF-I axis in the relationship between maternal glycemia during pregnancy and birth weight. We also show for the first time that high insulin concentration in female fetuses is associated with slower early postnatal growth. This slow, early growth pattern may be programmed by fetal hyperinsulinemia, and girls may be more susceptible than boys to its consequences.
A rapid increase in the prevalence of obesity has been reported in France since 1990. We investigated the impact of birth cohort on the changes in obesity prevalence after taking into account age and survey period.
We analyzed data from four national surveys in 1997, 2000, 2003 and 2006. For each survey, self-reported data on weight and height were recorded on mailed questionnaires sent to a sample of 20 000 households, representative of the French population. Obesity was defined according to WHO criteria, BMI ≥ 30 kg/m2. We modeled the prevalence of obesity using logistic regression with age, cohort and period as explanatory variables. As these variables are linearly dependent, only nonlinear effects can be estimated uniquely and interpreted, after including specific chosen constraints in the models.
There was a progressive increase in the prevalence of obesity between 1997 and 2006, attributable either to a period or to a cohort effect. There was a substantial departure from a linear trend for the cohort effect only, which appeared to be stronger in women: there was an acceleration in the prevalence of obesity with birth cohort for individuals born after the mid-1960s, in both sexes.
Our results are consistent with previous studies in other countries. Compared with older generations, men and women born in the late 1960s may have been subject to early exposures that increased their lifelong susceptibility to obesity.
Adolescent; Adult; Aged; Aged, 80 and over; Cohort Studies; Female; France; epidemiology; Health Surveys; Humans; Male; Middle Aged; Obesity; epidemiology; Young Adult
To evaluate the reproducibility of the measurement of % body fat by bipedal biometrical impedance analysis (BIA) compared with anthropometric measurements of adiposity in children and the correlations between these methods in children and adults.
cross-sectional study in a total of 1080 adults and children enrolled in 1999 in the Fleurbaix-Laventie Ville Santé II (FLVS II) population-based study in northern France. The reproducibility of anthropometrical and BIA methods was determined by a nested analysis of variance of repeated measurements by 2 investigators and a bipedal BIA device (Tanita® TBF 310) in 64 pupils of two 5th grade classes. The correlation of BIA and anthropometric adiposity measurements with the unknown relative fat mass or volume of the body estimated by a latent adiposity variable (LAV) was established by the triads’ method in 1080 subjects of the FLVS II cohort.
The reproducibility was similar for the sum of skinfolds, waist circumference and BIA % fat measurements (intraclass correlation coefficients: 0.979–0.992). Correlation coefficient between BIA body fat % and the LAV was higher than 0.86 in all sex and Tanner stage related groups, and similar in children and adults, except in pubertal boys (0.76).
With a high level of reproducibility, foot-to-foot BIA analysis provides a valuable measurement of total % fat for epidemiologic studies in children. However further studies are needed before extrapolating these results to overweight children.
Epidemiology; Anthropometric; Reproducibility; Correlations; Bioimpedance; Adipose Tissue; anatomy & histology; Adolescent; Adult; Analysis of Variance; Body Height; Body Mass Index; Body Size; Body Weight; Child; Electric Impedance; Female; France; Humans; Male; Middle Aged; Reproducibility of Results; Skinfold Thickness
Background: Data concerning the effects of prenatal exposures to phthalates and phenols on fetal growth are limited in humans. Previous findings suggest possible effects of some phenols on male birth weight.
Objective: Our aim was to assess the relationships between prenatal exposures to phthalates and phenols and fetal growth among male newborns.
Methods: We conducted a case–control study on male malformations of the genitalia nested in two French mother–child cohorts with recruitment between 2002 and 2006. We measured, in maternal urinary samples collected between 6 and 30 gestational weeks, the concentrations (micrograms per liter) of 9 phenol (n = 191 pregnant women) and 11 phthalate metabolites (n = 287). Weight, length, and head circumference at birth were collected from maternity records. Statistical analyses were corrected for the oversampling of malformation cases.
Results: Adjusted birth weight decreased by 77 g [95% confidence interval (CI): –129, –25] and by 49 g (95% CI: –86, –13) in association with a 1-unit increase in ln-transformed 2,4-dichlorophenol (DCP) and 2,5-DCP urinary concentrations, respectively. Benzophenone-3 (BP3) ln-transformed concentrations were positively associated with weight (26 g; 95% CI: –2, 54) and head circumference at birth (0.1 cm; 95% CI: 0.0, 0.2). Head circumference increased by 0.3 cm (95% CI: 0.0, 0.7) in association with a 1-unit increase in ln-transformed BPA concentration. For phthalate metabolites there was no evidence of monotonic associations with birth weight.
Conclusions: Consistent with findings of a previous study, we observed evidence of an inverse association of 2,5-DCP and a positive association of BP3 with male birth weight.
birth outcomes; fetal growth; phenols; phthalates; pregnancy exposure; urinary biomarkers
Physical activity is a major component of a healthy lifestyle in youth and adults. To identify determinants of this complex behavior is an important research objective in the process of designing interventions to promote physical activity at population level. In addition to individual determinants, there is evidence documenting familial influences on physical activity. However, the few studies that have addressed this issue with objective measures did not provide data on parent-offspring physical activity relationships throughout childhood and adolescence. The purpose of this study was to assess familial correlations in pedometer-assessed physical activity.
We measured ambulatory activity in 286 French nuclear families (283 mothers, 237 fathers, and 631 children aged 8–18 years) by pedometer recordings (Yamax Digiwalker DW 450) over a week. Correlations were computed with their 95% confidence intervals (CI) for spouse pairs, siblings, mother-offspring, and father-offspring. Data were expressed as steps per day and computed both for the full recording period and separately for weekdays and weekends.
The correlations were the highest between siblings (r = 0.28, 95%CI: 0.17–0.38). Parent–offspring correlations were significant in mothers (r = 0.21, 95%CI: 0.12–0.30), especially between mothers and daughters (r = 0.24, 95%CI: 0.12–0.36 vs. r = 0.18, 95%CI: 0.05–0.31 for sons), but were almost nonexistent in fathers. Correlations were generally higher on weekend days compared to weekdays. Mother-offspring correlations did not decrease with increasing age of children (r = 0.17, 95%CI: 0.00–0.34 in 8–11-year-olds, r = 0.20, 95%CI: 0.07–0.33 in 12–15-year-olds, and r = 0.25, 95%CI: 0.07–0.39 in ≥16-year-olds). Finally, between-spouse correlations were significant only during weekend days (r = 0.14, 95%CI: 0.01–0.27).
Ambulatory activity correlated within families, with a possible mother effect. Mother-offspring correlations remained significant through the transition from childhood to adolescence. Further studies are required to better understand the respective influences of shared activities, parental modeling and support as well as genetic factors on the familial aggregation of physical activity.
Maternal seafood intake is of great health interest since it constitutes an important source of n-3 fatty acids, but provides also an important pathway for fetal exposure to mercury (Hg).
To determine associations between Hg contamination and both maternal seafood consumption and fetal growth in French pregnant women.
Pregnant women included in the “EDEN mother-child” cohort study answered food frequency questionnaires on their usual diet in the year before and during the last three months of pregnancy, from which frequencies of seafood intake were evaluated. Total hair-Hg level was determined for the first 691 included women. Associations between Hg level, seafood intake and several neonatal measurements were studied using linear regressions adjusted for confounding variables.
The median Hg level for mothers was 0.52 μg/g. Maternal seafood intake was associated with Hg level (r=0.33, p<0.0001). There was no association between Hg level and fetal growth in the whole sample of women, except for an early negative relation with biparietal diameter. A positive association was found between seafood intake and fetal growth in overweight women only which remained unchanged after adjustment for Hg level (birthweight: +101g for a difference of 1SD in seafood consumption, p=0.008).
Although seafood intake was associated with Hg contamination in French pregnant women, the contamination level was low. There was no consistent association between Hg level and fetal growth. Taking into account Hg level did not modify associations between seafood intake and fetal growth.
Adult; Cohort Studies; Female; Fetal Growth Retardation; chemically induced; Food Contamination; Hair; chemistry; Humans; Infant, Newborn; Male; Mercury; analysis; toxicity; Pregnancy; Prenatal Exposure Delayed Effects; Seafood; Water Pollutants, Chemical; toxicity; Mercury; seafood consumption; prenatal exposure; fetal growth
Obesity and increases in body weight in adults are considered to be among the most important risk factors for type 2 diabetes. Low birth weight is also associated with a higher diabetes incidence. We aimed to examine to what extent the evolution of body shape, from childhood to adulthood, is related to incident diabetes in late adulthood.
RESEARCH DESIGN AND METHODS
Etude Epidemiologique de Femmes de la Mutuelle Générale de l'Education Nationale (E3N) is a cohort study of French women born in 1925–1950 and followed by questionnaire every 2 years. At baseline, in 1990, women were asked to report their current weight, height, and body silhouette at various ages. Birth weight was recorded in 2002. Cases of diabetes were self-reported or obtained by drug reimbursement record linkage and further validated.
Of the 91,453 women who were nondiabetic at baseline, 2,534 developed diabetes over the 15 years of follow-up. Birth weight and body silhouette at 8 years, at menarche, and in young adulthood (20–25 years) were inversely associated with the risk of diabetes, independently of adult BMI during follow-up (all Ptrend < 0.001). In mid-adulthood (35–40 years), the association was reversed, with an increase in risk related to a larger body silhouette. An increase in body silhouette from childhood to mid-adulthood amplified the risk of diabetes.
Low birth weight and thinness until young adulthood may increase the risk of diabetes, independently of adult BMI during follow-up. Young women who were lean children should be especially warned against weight gain.
Studies of the effects of air pollutants on birth weight often assess exposure with networks of permanent air quality monitoring stations (AQMSs), which have a poor spatial resolution.
We aimed to compare the exposure model based on the nearest AQMS and a temporally adjusted geostatistical (TAG) model with a finer spatial resolution, for use in pregnancy studies.
The AQMS and TAG exposure models were implemented in two areas surrounding medium-size cities in which 776 pregnant women were followed as part of the EDEN mother–child cohort. The exposure models were compared in terms of estimated nitrogen dioxide (NO2) levels and of their association with birth weight.
The correlations between the two estimates of exposure during the first trimester of pregnancy were r = 0.67, 0.70, and 0.83 for women living within 5, 2, and 1 km of an AQMS, respectively. Exposure patterns displayed greater spatial than temporal variations. Exposure during the first trimester of pregnancy was most strongly associated with birth weight for women living < 2 km away from an AQMS: a 10-μg/m3 increase in NO2 exposure was associated with an adjusted difference in birth weight of −37 g [95% confidence interval (CI), −75 to 1 g] for the nearest-AQMS model and of −51 g (95% CI, −128 to 26 g) for the TAG model. The association was less strong (higher p-value) for women living within 5 or 1 km of an AQMS.
The two exposure models tended to give consistent results in terms of association with birth weight, despite the moderate concordance between exposure estimates.
atmospheric pollution; birth weight; cohort; exposure modeling; geostatistical; measurement error; monitoring station; nitrogen dioxide; spatial variation; temporal variation
Recent studies suggest a benefit of seafood and n-3 Fatty Acids (FA) intake on fetal growth and infant development.
To study the association between FA intake and fetal growth in French pregnant women.
Pregnant women included in the EDEN mother-child cohort study answered food frequency questionnaires on their usual diet 1) in the year prior to pregnancy and 2) during the last three months of pregnancy (n=1439). Conversion into nutrient intakes was performed using data on portion size and a French food composition table. Associations between maternal FA intakes and several neonatal anthropometric measurements were studied using linear regressions adjusted for center, mother’s age, smoking habits, height, parity, gestational age and newborn’s sex. Due to significant interaction, analyses were stratified according to maternal pre-pregnancy overweight status.
Neither total lipid nor saturated, monounsaturated or polyunsaturated (PUFA) fat intake were significantly associated with newborn size. In overweight women only (n=366), a high pre-pregnancy n-3FA intake (% n-3FA/PUFA) was positively associated with newborn’s birthweight (p=0.01), head, arm and wrist circumferences and sum of skinfolds (p<0.04). A substitution of one percent of n-3FA per day before pregnancy by other PUFA was related to an average decrease in birthweight of 60 g (p=0.01). Relationships with n-3FA intake at the end of pregnancy were weaker and not significant.
A high pre-pregnancy ratio n-3FA/PUFA may sustain fetal growth in overweight women. Follow-up of the children may help determine whether this has beneficial consequences for the child’s health and development.
Adolescent; Adult; Birth Weight; Body Height; Diet; Fatty Acids; administration & dosage; Fatty Acids, Omega-3; administration & dosage; Fatty Acids, Unsaturated; administration & dosage; Female; Fetal Development; physiology; France; Humans; Infant, Newborn; Maternal Nutritional Physiological Phenomena; Middle Aged; Overweight; metabolism; Pregnancy; Pregnancy Complications; metabolism; Prenatal Exposure Delayed Effects; Prospective Studies; Regression Analysis; Seafood; Social Class; Epidemiology; Pregnancy; n-3 Fatty Acids; Birthweight; Overweight
Studies, in countries with high seafood consumption, suggested its benefit on fetal growth and child development. The objective of our study was to determine the association between seafood consumption in French pregnant women and fetal growth. Pregnant women included in the EDEN mother-child cohort study completed two food frequency questionnaires on their usual diet in the year before and during the last three months of pregnancy (n=1805). Fetal circumferences were measured by ultrasound, and anthropometry at birth. Variables were compared across tertiles of the mother’s seafood consumption by multiple linear regressions adjusted for confounding variables. Analyses were stratified according to maternal overweight because of interaction (p<0.01). As results, there was no association between seafood intake and fetal growth in the whole sample of women. For overweight women (n=464), a higher consumption before pregnancy was associated with higher fetal biparietal and abdominal circumferences and anthropometric measures. From the lowest to the highest tertiles, mean birthweight was 167g higher (p=0.002). No significant association was found with consumption at the end of pregnancy. In conclusion, high seafood consumption before pregnancy is positively associated with fetal growth in overweight women. Follow-up of the infants may help determine potential beneficial consequences for the child’s health and development.
Adipose Tissue; metabolism; Adolescent; Adult; Anthropometry; Child Development; physiology; Diet; Fatty Acids, Omega-3; metabolism; Female; Fetal Development; Fish Products; France; Gestational Age; Humans; Infant, Newborn; Maternal Nutritional Physiological Phenomena; Mothers; Overweight; Pregnancy; Questionnaires; Seafood; statistics & numerical data; Shellfish; Young Adult; Epidemiology; pregnancy; seafood; birthweight; fetal growth; overweight
Prior studies revealed associations of environmental lead exposure with risks of hypertension and elevated blood pressure.
We examined the effect of blood lead levels on blood pressure and the incidence of pregnancy-induced hypertension (PIH) in the second and third trimesters of pregnancy.
One thousand seventeen pregnant women were enrolled in two French municipalities between 2003 and 2005 for the EDEN (Etude des Déterminants pré et post natals du développement et de la santé de l′ Enfant) cohort study. Blood lead concentrations were measured by atomic absorption spectrometry in mothers between 24 and 28 weeks of gestation.
PIH was diagnosed in 106 subjects (10.9%). Age, parity, weight gain, alcohol, smoking habits, and calcium supplementation were comparable between hypertensive and nonhypertensive women. Lead levels were significantly higher in PIH cases (mean ± SD, 2.2 ± 1.4 μg/dL) than in normotensive patients (1.9 ± 1.2 μg/dL; p = 0.02). Adjustment for potential confounder effects slightly attenuated but did not eliminate the significant association between blood lead levels and the risk of PIH (adjusted odds ratio of PIH = 3.3; 95% confidence interval, 1.1–9.7). We also observed geographic differences in lead exposure and in the incidence of PIH and found significant correlations between blood lead levels and unadjusted as well as adjusted systolic and diastolic blood pressures after 24 weeks of gestation.
These findings confirm the relationship between blood lead levels at mid-pregnancy and blood pressure and suggest that environmental lead exposure may play an etiologic role in PIH.
cadmium; environmental health; epidemiology; gestation; hypertension; lead; manganese
Studies relying on outdoor pollutants measures have reported associations between air pollutants and birth weight.
Our aim was to assess the relation between maternal personal exposure to airborne benzene during pregnancy and fetal growth.
We recruited pregnant women in two French maternity hospitals in 2005–2006 as part of the EDEN mother–child cohort. A subsample of 271 nonsmoking women carried a diffusive air sampler for a week during the 27th gestational week, allowing assessment of benzene exposure. We estimated head circumference of the offspring by ultrasound measurements during the second and third trimesters of pregnancy and at birth.
Median benzene exposure was 1.8 μg/m3 (5th, 95th percentiles, 0.5, 7.5 μg/m3). Log-transformed benzene exposure was associated with a gestational age–adjusted decrease of 68 g in mean birth weight [95% confidence interval (CI), −135 to −1 g] and of 1.9 mm in mean head circumference at birth (95% CI, −3.8 to 0.0 mm). It was associated with an adjusted decrease of 1.9 mm in head circumference assessed during the third trimester (95% CI, −4.0 to 0.3 mm) and of 1.5 mm in head circumference assessed at the end of the second trimester of pregnancy (95% CI, −3.1 to 0 mm).
Our prospective study among pregnant women is one of the first to rely on personal monitoring of exposure; a limitation is that exposure was assessed during 1 week only. Maternal benzene exposure was associated with decreases in birth weight and head circumference during pregnancy and at birth. This association could be attributable to benzene and a mixture of associated traffic-related air pollutants.
atmospheric pollution; benzene; birth weight; cohort; fetal growth; head circumference; personal monitoring; sensitivity analysis; ultrasonography
The objective of the study is to describe the prevalences of obesity in French adults over a 9 year period. Mailed questionnaire surveys, in 1997, 2000, 2003 and 2006, sampled 20,000 representative French households by the method of quotas Weight, height and waist circumference were reported by all members of the selected households 18 years and older. Obesity was defined according to WHO criteria, BMI < 25 kg/m2.
The prevalence of adult obesity increased progressively from 8.6 % (95% confidence interval: 8.2–8.8) in 1997 to 13.1 % (12.7–13.5) in 2006. The increase affected all ages, socio economic strata and regions. While the prevalence of obesity increased in parallel in men and women from 1997 to 2003, the rate of increase was lower in men between 2003 and 2006.
These surveys showed a sharp increase in the prevalence of obesity in France in recent years contrasting with a stable prevalence in the 1980s. The results of the first Obepi surveys prompted the French government to implement a Nutrition and Health National Plan in 2001. Regular monitoring of obesity prevalence in France and neighboring countries is needed to compare future trends.
Adolescent; Adult; Aged; Aged, 80 and over; Body Height; Body Mass Index; Body Weight; Disease Outbreaks; Female; France; epidemiology; Humans; Male; Middle Aged; Obesity; epidemiology; Overweight; epidemiology; Prevalence; Socioeconomic Factors; Waist Circumference; Young Adult; adults; epidemiology; prevalence; socioeconomics; obesity
Our aim was to evaluate the reproducibility of a food frequency questionnaire (FFQ) developed in a French population, and its validity against four 24-hour dietary recalls (24-HR).
57 adults (aged 18 to 63), 17 adolescents (aged 14 to 18), and 20 children (aged 10 to 14) completed four 24-HRs (one per season) and two FFQs over a 1-year interval. Reproducibility of the FFQ was estimated by intraclass correlation coefficients (ICCs). The validity of FFQ was assessed by comparison with the four 24-HRs.
For most nutrients, the first FFQ measurements gave higher mean values than the second FFQ. The ICCs for nutrients ranged from 0.39 for total protein to 0.83 for alcohol. The ICCs were higher for food items consumed daily such as milk (0.80) or sugars and confectionnery (0.65), and lower for rarely eaten food such as inner organs (0.11). Nutrient intakes as assessed by FFQs were higher than those from the 24-HRs, except for alcohol. The de-attenuated Pearson’s correlation coefficient for nutrients varied from 0.25 (dietary fiber) to 0.90 (alcohol), but the adjustment for energy did not improve these coefficients. When nutrient intakes were categorized into quintiles, FFQ and 24-HRs produced agreement rates (same or adjacent quintile) between 55% (for PUFA) and 95% (for alcohol), while misclassification to an extreme quintile was rare (<5%).
The FFQ developed for the FLVS II Study can be used to classify adults or adolescents according to their nutrients and food intakes over a one-year period.
validation; food frequency questionnaire; adult; adolescent
To compare the sensitivities of BMI, waist circumference and waist hip ratio (WHR) in identifying subjects who should be screened for diabetes and/or for obesity-associated dyslipidaemia.
More than 3000 men and women, aged 40 to 64 years, from the French study: Data from an Epidemiological Study on the Insulin Resistance syndrome (D.E.S.I.R.).
Main outcome measures
Sensitivity and specificity for screened diabetes (fasting plasma glucose ≥ 7.0 mmol/l) and screened dyslipidaemia (triglycerides ≥ 2.3 mmol/l and/or HDL-cholesterol < 0.9/1.1 mmol/l (men/women)) according to BMI, waist circumference and WHR..
Sensitivities increased as more corpulent subjects were screened, but they increased slowly after screening the top 30%: BMI ≥ 27/26 kg/m2 (men/women) or waist ≥ 96/83 cm or WHR ≥ 0.96/0.83, These values were chosen as thresholds. In men, BMI had a non-significantly higher sensitivity than waist or WHR for both diabetes and dyslipidaemia (77% vs 74% and 66% P < 0.3, 0.09; 56% vs 54% and 49% P < 0.5, 0.16). For women, waist had a slightly higher sensitivity than BMI or WHR (82% vs 77% and 77% P < 0.8, 0.7) for diabetes; for dyslipidaemia, waist and WHR had similar sensitivities, higher than for BMI (65% and 67% vs 54% P < 0.16, 0.13).
We propose that for screening in a French population 40 to 64 years of age, the more obese 30% of the population, identified either by BMI, waist or WHR be screened for diabetes and obesity-associated dyslipidaemia.
Adult; Analysis of Variance; Body Composition; physiology; Body Mass Index; Cross-Sectional Studies; Diabetes Mellitus, Type 2; blood; diagnosis; epidemiology; Dyslipidemias; blood; diagnosis; epidemiology; Female; France; epidemiology; Humans; Insulin Resistance; Male; Mass Screening; methods; Middle Aged; Obesity; blood; complications; diagnosis; epidemiology; Risk Factors; Sensitivity and Specificity; Sex Factors; Waist-Hip Ratio
To investigate the hypothesis that plasma leptin may predict adiposity changes.
A population-based cohort study.
Fleurbaix and Laventie, in the north of France.
1175 subjects participated, of whom 946 completed measurements at baseline (1999) and follow-up (2001). After excluding 64 subjects obese at baseline, 882 subjects (478 adults, 404 children 8y and over) were included in the analysis.
We measured plasma leptin concentrations at baseline and various adiposity parameters at baseline and follow-up. Partial correlation coefficients (rp) between baseline plasma leptin and each adiposity indicator at follow-up were calculated with adjustment for baseline age, pubertal stage, adiposity and familial correlations between siblings.
Changes in body mass index and % body fat were not related to baseline plasma leptin. High baseline plasma leptin predicted an increase (rp (p value)) in the sum of the four skinfolds (0.18 (<0.0001)), the waist circumference (0.16 (0.0003)) and the waist-to-hip ratio (0.29 (<0.0001)) in adults only, and in the hip circumference in adults (0.20 (<0.0001)) and children (0.22 (<0.0001)). After adjustment for a set of 4 adiposity variables at baseline (% body fat, skinfolds, waist and hip circumferences), baseline plasma leptin predicted only changes in the sum of the four skinfolds in adults (0.15 (0.001)), with similar tendency although not significant in children (0.08 (0.13)).
A high leptin relative to baseline fat mass predicts fat mass gain over time, mainly in the subcutaneous location.
Supported by Knoll, Centre d’Etudes et de Documentation du Sucre (CEDUS), Groupe Fournier, Lesieur, Nestlé France, Produits Roche, Le Centre d’Information Scientifique sur la Bière (CISB).
adipocytokins; insulin; adipose tissue; epidemiology
Adult; Body Composition; Body Mass Index; Child; Cohort Studies; Female; Follow-Up Studies; France; Humans; Leptin; blood; Male; Obesity; blood; epidemiology; etiology; Predictive Value of Tests; Skinfold Thickness; Subcutaneous Fat; growth & development; metabolism; Waist-Hip Ratio; Weight Gain
To investigate in adolescents, relationships between habitual physical activity (PA) and changes in several indicators of adiposity.
To investigate in adolescents from a population-based study, relationships between habitual physical activity (PA) and changes in several indicators of adiposity.
Longitudinal population-based study. The Fleurbaix-Laventie Ville Santé II (FLVS II) study in northern France.
A total of 222 boys and 214 girls aged 8–18 y, not obese at inclusion.
PA (Modifiable Activity Questionnaire) and adiposity (BMI, % body fat by bio-impedance analysis, sum of 4 skinfolds, waist circumference) were assessed in 1999 and 2001. Adiposity indicators adjusted for age and pubertal stage were compared between groups of baseline PA and between groups of PA changes, separately by sex.
At baseline, PA was not associated with adiposity indicators in both sexes. In girls only, being in the group with the highest age-relative level of moderate PA at baseline predicted the highest adiposity gain from baseline to follow-up, for all indicators. After adjustment for baseline values, all adiposity indicators were higher at follow-up in girls who had decreased their relative level of moderate PA during follow-up. In boys, changes in adiposity during follow-up were not significantly different across groups of PA changes. However, the sum of skinfolds at follow-up, adjusted for baseline value, tended to be higher in those who decreased their vigorous PA level and lower in those who increased it.
In adolescent girls, a decrease in PA rather than inactivity per se may result in increased adiposity over time.
Adipose Tissue; anatomy & histology; Adolescent; Age Factors; Body Composition; Body Mass Index; Chi-Square Distribution; Child; Exercise; Female; Humans; Longitudinal Studies; Male; Sex Factors; Skinfold Thickness
Among hepatic markers, gamma-glutamyltransferase (GGT) is the main predictor for the development of type 2 diabetes, but there is no data on GGT change and type 2 diabetes incidence.
Data at baseline and at three years from the D.E.S.I.R. cohort were used: 2071 men and 2130 women without baseline diabetes.
Change in GGT level was correlated with changes in markers of insulin-resistance (fasting insulin, HOMA index) as well as with elements of the metabolic syndrome: fasting glucose, central obesity, triglycerides, systolic and diastolic blood pressure. The three-year increase in GGT was associated with incident type 2 diabetes, in both sexes, after adjusting for age and baseline GGT. After further adjustment for baseline confounding factors including alanine-aminotransferase, alcohol intake, overall and central obesity, the odds ratios (95% Cl) for incident type 2 diabetes associated with an increase compared to a decrease in GGT level were 2.54 (1.38–4.68) in men (p<0.003) and 2.78 (1.20–6.42) in women (p<0.02). These associations were slightly attenuated after adjusting for the 3-year change in BMI, alcohol consumption, fasting insulin: 2.49 (1.28–4.86) in men and 2.53 (1.01–6.40) in women. This relationship was not dependent on intra-individual variability.
An increase in GGT level over time, even when GGT is in the normal range, is correlated with increasing insulin resistance and is associated with a risk of incident type 2 diabetes in both sexes, independently of baseline GGT, which is itself a diabetes risk factor.
Body Mass Index; Cohort Studies; Diabetes Mellitus, Type 2; blood; enzymology; epidemiology; Female; France; epidemiology; Humans; Insulin; blood; Longitudinal Studies; Male; Middle Aged; Odds Ratio; Risk Factors; Sex Characteristics; gamma-Glutamyltransferase; blood
We identified a childhood obesity locus on chromosome 6q16.3-q24.21 that includes 2.4 Mb common to eight genome scans for Type 2 diabetes (T2D) or obesity1-8. Analysis of the ENPP1 (PC-1) gene, a candidate for insulin resistance9,10 in 6,147 subjects revealed association between a three allele risk haplotype (K121Q/IVS20 delT-11/A>G +1044 TGA, QdelTG) and childhood obesity (OR=1.69, p=0.0006), and in adults with morbid or moderate obesity (OR= 1.50, p= 0.006, OR= 1.37, p= 0.02) and also with T2D (OR=1.56, p=0.00002). The Genotype IBD Sharing Test suggested a contribution of this obesity-associated ENPP1 risk haplotype to the observed chromosome 6q linkage with childhood obesity. The haplotype confers a higher risk of glucose intolerance and T2D to obese children and to their parents and associates with increased serum levels of soluble ENPP1 protein in children. Expression of a long ENPP1 mRNA isoform, which includes the obesity-associated A>G +1044 TGA SNP, was found to be specific for pancreatic islet beta-cells, adipocytes and liver. These findings suggest a primary role for several variants of ENPP1 in mediating insulin-resistance, in the development of both obesity and type 2 diabetes, suggesting an underlying molecular mechanism common to both widespread afflictions.
To document for the first time in a general population of French children, the prevalence and levels of cardiovascular risk factors, and to assess, separately in boys and girls, whether these risk factors were associated with fat mass distribution independently of subcutaneous overall adiposity.
Subjects and design
A cross sectional analysis of baseline data from 452 children (235 boys and 217 girls) aged 8–17 years included in 1999 in a population-based epidemiologic study, the Fleurbaix Laventie Ville Santé II (FLVS II) study.
Overweight was defined according to the International Obesity Task Force (IOTF) references and to the 90th percentiles of the French BMI curves. The thresholds of parameters defining cardiovascular and metabolic risk were the 95th percentile of the Task Force Report on High Blood Pressure in Children and Adolescents for blood pressure, and those of the American Academy of Pediatrics for lipids. Anthropometric and biologic parameters were described by gender and according to overweight. Partial correlations between cardiovascular risk factors and anthropometric measures of adiposity (BMI, sum of four skinfold thicknesses, waist circumference, waist-to-height ratio) were calculated. In a second step, these correlations were additionally adjusted for the sum of four skinfold thicknesses.
High plasma triglycerides, high insulin concentration and low plasma HDL cholesterol were associated with all measures of adiposity (|r|≥0.20; p<0.002). When obese children were excluded, overweight children already had high triglycerides and low HDL cholesterol levels respectively 2 and 20 times more frequently than normal weight children. Among overweight children, 7.7% had at least two risk factors among high blood pressure, high plasma triglycerides or glucose, and low HDL concentrations, versus 0.25% among normal weight children (p=0.002). After adjusting for the sum of skinfolds, an independent association between the risk factors and waist circumference was found in girls.
(a) Modest excess weight is associated with increased levels of cardiovascular risk factors. (b) In girls, abdominal fat distribution is associated with cardiovascular risk factors, independently of overall adiposity. (c) International definition of abdominal obesity in children is required to standardize studies and progress in the evaluation of childhood obesity and its consequences.
Abdominal Fat; Adolescent; Anthropometry; Blood Glucose; metabolism; Blood Pressure; physiology; Cardiovascular Diseases; blood; epidemiology; Child; Cholesterol; blood; Cross-Sectional Studies; Female; France; epidemiology; Humans; Insulin; blood; Male; Obesity; blood; epidemiology; Prevalence; Risk Factors; Triglycerides; blood
The Pro12Ala Single Nucleotide Polymorphism (SNP) of the Peroxisome Proliferator-Activated Receptor gamma 2 (PPAR-gamma 2) has been associated with insulin resistance and type 2 diabetes (T2D) and also inconsistently with obesity. The aim of this study was to evaluate the impact of this SNP with regards to T2D and childhood and adult obesity in the French Caucasian population.
We conducted three independent case/control studies encompassing 2126 cases and 1124 controls.
We found a significant association between PPAR-gamma 2 Pro12Ala SNP and T2D (p = 0.04, OR = 1.37), which was stronger when the T2D cohort was stratified according to the obesity status (p = 0.03, OR = 1.81 in obese T2D subjects). In contrast, there was no association between the Pro12Ala SNP and childhood and adulthood obesity. In normal glucose tolerant obese adults (but not in lean subjects), the Pro12 allele was associated with a significant increase in fasting insulin levels (p = 0.01), and in insulin resistance estimated by the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) (p = 0.003), after adjustment for age, gender and BMI. We didn't detect evidence for an interaction effect between the Pro12Ala SNP and the obesity status with respect to the HOMA-IR index in normal glucose tolerant children, but we found a borderline interaction (p = 0.06) in normal glucose tolerant adults.
Our results showed that the Pro12Ala polymorphism is not associated with childhood or adult obesity in the French Caucasian population. In contrast, we confirm a contribution of the PPAR-gamma 2 Pro12 allele in the genetic risk forT2D, especially in obese subjects, where this allele worsens insulin resistanceand increases fasting insulin levels.