Socioeconomic inequalities in weight, height and body mass index from birth to 5 years.

BACKGROUND/OBJECTIVES: Studies in high-income countries show that despite the positive association of weight with socioeconomic position at birth, an inverse socioeconomic gradient in overweight (OW) appears later in childhood. The objectives were to understand the natural history of socioeconomic inequalities in weight, height and body mass index (BMI), by investigating their associations with maternal educational level between birth and 5 years, separately in boys and girls. SUBJECTS/METHODS: A published work of growth modelling between birth and 5 years allowed us to calculate predicted weight, height and BMI at 1 month, 6 months, 1, 3 and 5 years for 1735 children from the French EDEN mother-child cohort. Associations between maternal education and predicted measures of body size were analysed with marginal linear and logistic models, stratified by sex. RESULTS: In girls, despite a positive association between maternal education and birthweight, an inverse socioeconomic gradient was observed as early as 1 month for BMI. Girls whose mothers had low education levels were shorter on the whole than their counterparts with better-educated mothers, despite their similar weights. In boys, no socioeconomic gradient in BMI was observed at any age, including birth, but positive associations were found as early as 1 month for both weight and height. CONCLUSIONS: The emergence of an inverse socioeconomic gradient in BMI and OW apparently results from a complex pattern of socioeconomic inequalities in weight and height from 1 month onwards. The very start of life thus appears to be an important window of opportunity for addressing socioeconomic inequalities in growth.

Prospective associations between energy balance-related behaviors at 2 years of age and subsequent adiposity: the EDEN mother-child cohort.

BACKGROUND/OBJECTIVES: Sedentary behavior, physical activity and dietary behavior are formed early during childhood and tend to remain relatively stable into later life. No longitudinal studies have assessed the independent influence of these three energy balance-related behaviors during toddlerhood on later adiposity. We aimed to analyze the associations between TV/DVD watching time, outdoor play time and dietary patterns at the age of 2 years and child adiposity at the age of 5 years, in boys and girls separately. SUBJECTS/METHODS: This study included 883 children from the French EDEN mother-child cohort. TV/DVD watching time, outdoor play time and dietary intakes were reported by parents in questionnaires when the child was aged 2 years. Two dietary patterns, labeled 'Guidelines' and 'Processed, fast foods', were identified in a previous study. The percentage of body fat (%BF) based on bioelectrical impedance analysis and body mass index were measured at the age of 5 years. RESULTS: In boys, TV/DVD watching time at the age of 2 years was positively associated with %BF at the age of 5 years (ß=0.50 (95% confidence interval: 0.001, 1.00) for those boys with ⩾60 min per day of TV/DVD watching time vs those with ⩽15 min per day, P-value for trend 0.05). In girls, outdoor play was inversely associated with %BF (ß=-0.96 (95% confidence interval: -1.60, -0.32) for those in the highest tertile of outdoor play time vs those in the lowest tertile, P=0.001). Overall, at the age of 2 years, dietary patterns were associated with both TV/DVD watching time and outdoor play time, but no significant and independent association was observed between dietary patterns and later adiposity. CONCLUSION: This study shows longitudinal and gender-differentiated relations between both TV/DVD watching time and outdoor play time in toddlerhood and later adiposity, whereas evidence for a relation between dietary patterns and subsequent fat development was less conclusive. Early childhood-by the age of 2 years-should be targeted as a critical time for promoting healthy energy balance-related behaviors.

Dietary acrylamide intake during pregnancy and anthropometry at birth in the French EDEN mother-child cohort study.

BACKGROUND AND AIM: Acrylamide is a contaminant formed in a wide variety of carbohydrate-containing foods during frying or baking at high temperatures. Recent studies have suggested reduced foetal growth after exposure to high levels of acrylamide during pregnancy. OBJECTIVE: To study the relationship between maternal dietary acrylamide intake during pregnancy and their offspring's anthropometry at birth. DESIGN: In our population of 1471 mother-child pairs from two French cities, Nancy and Poitiers, dietary acrylamide intake during pregnancy was assessed by combining maternal food frequency questionnaires with data on food contamination at the national level, provided by the second "French Total Diet Study". Newborns weighing less than the 10th percentile, according to a customised definition, were defined as small for gestational age (SGA). Linear and logistic regression models were used to study continuous and binary outcomes respectively, adjusting for the study centre, maternal age at delivery, height, education, parity, smoking during pregnancy, the newborn's gestational age at birth and sex. RESULTS: The median and interquartile range of dietary acrylamide intake were 19.2µg/day (IQR, 11.8;30.3). Each 10µg/day increase in acrylamide intake was associated with an odds-ratio for SGA of 1.11 (95% Confidence Interval: 1.03,1.21), birth length change of -0.05cm (95% CI: -0.11,0.00) and birth weight change of -9.8g (95% CI: -21.3,1.7). CONCLUSIONS: Our results, consistent with both experimental and epidemiological studies, add to the evidence of an effect of acrylamide exposure on the risk of SGA and suggest an effect on foetal growth, for both weight and length.

Evaluation of zeta potential of nanomaterials by electrophoretic light scattering: Fast field reversal versus Slow field reversal modes.

Zeta potential of nanomaterials designed to be used in nanomedicine is an important parameter to evaluate as it influences in vivo behaviour hence biological activity, efficacy and safety. As mentioned by the International Organization for Standardization (ISO), electrophoretic light scattering is a relevant method for evaluating zeta potential. The present work aimed to validate a new protocol based on the application of Fast Field Reversal mode and to explore its scope with nanomaterials investigated as nanomedicines. Its scope was then compared with that of an already validated protocol which uses both Fast Field Reversal and Slow Field Reversal modes. The new protocol was validated within the framework of the application of the Smoluchowski approximation. Its performances complied with the ISO standard. The protocol could be applied to evaluate mean zeta potential of soft nanomaterials including polymer-based nanoparticles and liposomes. However, it appeared unsuitable to evaluate zeta potential of dense nanomaterials including rutile titanium dioxide nanoparticles. Compared with the previously validated protocol which only applied to the determination of zeta potential of polymer nanoparticles, this new validated protocol gives access to the determination of zeta potential to a wider range of nanomedicines under conditions complying with quality control assessments.

Environmental contaminants and child's growth.

Experimental data have suggested that some contaminants in the environment may increase the risk of obesity. Infants can be exposed to chemicals either prenatally, by trans-placental passage of chemicals, or postnatally by their own diet and by other external pathways (air inhalation, dust, hand-to-mouth exposure) after birth. To provide a review of epidemiological evidence on the association between prenatal exposure to chemicals and prenatal and postnatal growth, we present the literature from systematic review articles and international meta-analyses, when available, or recent research articles when summarizing articles were not available. The most studied contaminants in this field were persistent organic pollutants (e.g. organochlorinated pesticides, polychlorinated biphenyls), non-persistent pollutants (e.g. phthalates, bisphenol A), toxic heavy metals (i.e. cadmium, lead and mercury), arsenic, mycotoxins and acrylamide. Mounting evidence suggests that child's growth may be associated with prenatal or postnatal exposures to environmental contaminants. Improving exposure assessment and studying the contaminants as mixtures should allow to gain knowledge about the environmental determinants of growth and obesity.

To which mixtures are French pregnant women mainly exposed? A combination of the second French total diet study with the EDEN and ELFE cohort studies.

Pregnant women and their unborn child are exposed to a large number of substances during pregnancy. Some of these substances may cross the placenta, resulting in exposure of the foetus. There is growing evidence that certain substances could interact to produce a mixture effect. It is therefore essential to identify the main mixtures mothers are exposed to. This study aimed to identify the major mixtures French pregnant women included in EDEN and ELFE cohorts were exposed to, on the basis of the 441 substances analysed in the second French total diet study. Exposure systems and the composition of substances were identified from co-exposures using sparse non-negative matrix under-approximation to generate the main mixtures. Individuals were clustered to define clusters with similar co-exposure profiles. Six clusters associated with eight mixtures were identified. For example in ELFE, cluster 2 comprising 10% of the population was characterised by mixtures "Pest-1" mainly contains pesticides and "TE-F-PAH″ contains trace elements, furans and polycyclic aromatic hydrocarbons. Five other clusters were also described with their associated mixtures. Similar results were observed for EDEN. This study helps to prioritise mixtures for which it is crucial to investigate possible toxicological effects and to recommend epidemiological studies concerning health effects.

Relationship between gamma-glutamyltransferase and fat mass in a general population of 8-17 years old children. The FLVS II study.

AIM: Elevated gamma-glutamyltransferase (GGT) is positively associated with severity of obesity in obese children and with increased BMI and waist circumference in general populations of adults. We aimed to study the relationships between GGT and anthropometric parameters in a general population of children. METHODS: This cross-sectional study was conducted in 219 boys and 214 girls included in the Fleurbaix Laventie Ville Santé II study. Weight, height, four skinfolds and waist circumference were measured. We compared the means of GGT activity according to gender and Tanner stage, and according to overweight status (IOTF definition) and quartiles of anthropometric parameters. We then calculated partial Pearson correlations by gender between GGT and anthropometric parameters taking age and Tanner stage into account. RESULTS: GGT activity was higher in boys than in girls as soon as puberty started (P<0.001). The higher difference was observed for Tanner stage III (GGT=10.2 UI/L, CI95% of mean (9.5, 11.1) vs. 7.8 UI/L (7.2, 8.4)). Anthropometric parameters were significantly associated with GGT, particularly waist circumference (r=0.28 in boys; r=0.24 in girls). After an additional adjustment for sum of skinfolds, this correlation disappeared in boys (r=0.06), and was still significant in girls (r=0.19). CONCLUSION: In a general population of children, overweight and abdominal fat distribution were associated with increased GGT. As some studies have shown that GGT could predict the metabolic syndrome in children and type 2 diabetes in adults, the modest elevation of GGT observed in overweight children may be of pathophysiological importance in the long term.

Influence of infant feeding patterns over the first year of life on growth from birth to 5 years.

OBJECTIVES: As early-life feeding experiences may influence later health, we aimed to examine relations between feeding patterns over the first year of life and child's growth in the first 5 years of life. METHODS: Our analysis included 1022 children from the EDEN mother-child cohort. Three feeding patterns were previously identified, i.e. 'Later dairy products introduction and use of ready-prepared baby foods' (pattern-1), 'Long breastfeeding, later main meal food introduction and use of home-made foods' (pattern-2) and 'Use of ready-prepared adult foods' (pattern-3). Associations between the feeding patterns and growth [weight, height and body mass index {BMI}] were analysed by multivariable linear regressions. Anthropometric changes were assessed by the final value adjusted for the initial value. RESULTS: Even though infant feeding patterns were not related to anthropometric measurements at 1, 3 and 5 years, high scores on pattern-1 were associated with higher 1-3 years weight and height changes. High scores on pattern-2 were related to lower 0-1 year weight and height changes, higher 1-5 years weight and height changes but not to BMI changes, after controlling for a wide range of potential confounding variables including parental BMI. Scores on pattern-3 were not significantly related to growth. Additional adjustment for breastfeeding duration reduced the strength of the associations between pattern-2 and growth but not those between pattern-1 and height growth. CONCLUSION: Our findings emphasize the relevance of considering infant feeding patterns including breastfeeding duration, age of complementary foods introduction as well as type of foods used when examining effects of early infant feeding practices on later health. © 2017 World Obesity Federation.

Towards quality assessed characterization of nanomaterial: Transfer of validated protocols for size measurement by dynamic light scattering and evaluation of zeta potential by electrophoretic light scattering.

Quality control analysis of nanomaterials has been identified as a major issue to pursue their development in different industrial fields including nanomedicine. One difficulty is the lack of standardized and validated protocols suitable to achieve their characterization. In a previous work, we have developed standardized protocols for the evaluation of the size and zeta potential of nanomaterials based on methods described in the ISO standard and have performed validation of each one. The present work was aimed to transfer these protocols in three independent receiving laboratories. No official guideline was described in the literature to achieve such a transfer. A comparative study for receiving laboratories equipped with the same instrument as the sending laboratory was designed based on the Code of Federal Regulation edited by the Food and Drug Administration. For the receiving laboratory equipped with an instrument working at a different wavelength, a new validation was designed and applied. Corresponding statistical methods were used for the analysis of the results. A successful transfer of the protocols in all receiving laboratories was achieved. All laboratories recorded consistent results applying in blind the protocol of size measurements on two samples of nanomaterials from which included one reference.

Size of monodispersed nanomaterials evaluated by dynamic light scattering: Protocol validated for measurements of 60 and 203nm diameter nanomaterials is now extended to 100 and 400nm.

In vivo fate of nanomaterials is influenced by the particle size among other parameters. Thus, Health Agencies have identified the size of nanomaterial as an essential physicochemical property to characterize. This parameter can be explored by dynamic light scattering (DLS) that is described in the ISO standard 22412:2008(E) and is one of the methods recognized by Health Agencies. However, no protocol of DLS size measurement has been validated over a large range of size so far. In this work, we propose an extension of validation of a protocol of size measurement by DLS previously validated with certified reference materials (CRM) at 60 and 203nm. The present work reports robustness, precision and trueness of this protocol that were investigated using CRM at 100 and 400nm. The protocol was robust, accurate and consistent with the ISO standard over the whole range of size that were considered. Expanded uncertainties were 4.4 and 3.6% for CRM at 100 and 400nm respectively indicating the reliability of the protocol. The range of application of the protocol previously applied to the size measurement of liposomes and polymer nanoparticles was extended to inorganic nanomaterial including silica nanoparticles.

Contamination of Pantopaque by glass.

Investigation has shown that when ampules containing Pantopaque are opened, a variable amount of fragments of glass may fall into the Pantopaque. When the Pantopaque is injected into the spinal canal these fragments may also be injected. As yet the results of injecting fragments of glass into the spinal subarachnoid space are unknown. The glass can be removed by passing the Pantopaque through a 0.22 micron Millex Filter.

Persistent organic pollutants and diabetes: a review of the epidemiological evidence.

The prevalence of diabetes and obesity has increased rapidly over the last few decades in both developed and developing countries. While it is intuitively appealing to suggest that lifestyle risk factors such as decreased physical activity and adoption of poor diets can explain much of the increase, the evidence to support this is poor. Given this, there has been an impetus to look more widely than traditional lifestyle and biomedical risk factors, especially those risk factors, which arise from the environment. Since the industrial revolution, there has been an introduction of many chemicals into our environment, which have now become environmental pollutants. There has been growing interest in one key class of environmental pollutants known as persistent organic pollutants (POPs) and their potential role in the development of diabetes. This review will summarise and appraise the current epidemiological evidence relating POPs to diabetes and highlight gaps and flaws in this evidence.