Maternal and early-life area-level characteristics and childhood adiposity: A systematic review

Associations between paediatric obesity, chemical mixtures and environmental factors, in a national cross-sectional study of Canadian children

BACKGROUND

Whilst single chemical exposures are suspected to be obesogenic, the combined role of chemical mixtures in paediatric obesity is not well understood.

OBJECTIVES

We aimed to evaluate the potential associations between chemical mixtures and obesity in a population-based sample of Canadian children.

METHODS

We ascertained biomonitoring and health data for children aged 3-11 from the cross-sectional Canadian Health Measures Survey from 2007 to 2019. Several chemicals of interest were measured in blood or urine and paediatric obesity was defined based on measured anthropometrics. Using quantile-based G computational analysis, we quantified the effects of three chemical mixtures selected a priori. Models were adjusted for sociodemographic and environmental factors identified through a directed acyclic graph. Results are presented through adjusted relative risks (RR) with 95% confidence intervals (95% CI).

RESULTS

We included 9147 children. Of these, 24.1% were overweight or obese. Exposure to the mixture of bisphenol A, acrylamide, glycidamide, metals, parabens and arsenic increased the risk of childhood overweight or obesity by 45% (95% CI 1.09, 1.93), obesity by 109% (95% CI 1.27, 3.42) and central obesity by 82% (95% CI 1.30, 2.56).

CONCLUSIONS

Our findings support the role of early childhood chemical exposures in paediatric obesity and the potential combined effects of chemicals.

Acceptability of the FIGO Nutrition Checklist in Preconception and Early Pregnancy to Assess Nutritional Status and Prevent Excess Gestational Weight Gain: A Study of Women and Healthcare Practitioners in the UK

Optimum nutrition and weight before and during pregnancy are associated with a lower risk of conditions such as pre-eclampsia and gestational diabetes. There is a lack of user-friendly tools in most clinical settings to support healthcare practitioners (HCPs) in implementing them. This study aimed to evaluate the acceptability of (1) using a nutrition checklist designed by the International Federation of Gynecology and Obstetrics (FIGO) for nutritional screening of women in the preconception and early pregnancy period and (2) routine discussion of nutrition and weight in clinical care. An online cross-sectional survey was conducted with women (aged 18-45) and HCPs (e.g., general practitioners, obstetricians, and midwives). Quantitative statistical analysis and qualitative content analysis were performed. The concept and content of the checklist were acceptable to women (n = 251) and HCPs (n = 47) (over 80% in both groups). Several barriers exist to implementation such as lack of time, training for HCPs, and the need for sensitive and non-stigmatizing communication. Routine discussion of nutrition was considered important by both groups; however, results suggest that nutrition is not regularly discussed in perinatal visits in the UK. The FIGO nutrition checklist presents a valuable resource for use in clinical practice, offering long-term and intergenerational benefits for both mother and baby.

Traffic noise and adiposity: a systematic review and meta-analysis of epidemiological studies

Traffic noise has attracted much attention as a significant and intractable public health threat. This study was designed as a systematical review to explore the association of traffic noise with different indicators of obesity, thus providing updated quantitative estimates for the pooled effect estimates of the existing literature. We conducted an extensive search for epidemiological studies that investigated the association of traffic noise with obesity in three electronic databases till February 23, 2021. We used random-effects meta-analysis to calculate the summary effect estimates for each 10-dB(A) increase in noise and compared the highest with the lowest category of noise in relation to seven obesity indicators. Meanwhile, we assessed the risk of bias and the overall quality of the evidence of each study as well as the level of evidence for each exposure-outcome pair. The initial search identified 30 studies, 13 of which were ultimately included. The meta-analysis for the highest versus the lowest category of noise exposure was generally associated with higher waist circumfluence (WC) ranging from 0.326 cm (95% confidence interval (CI) = 0.078, 0.574) to 0.705 cm (95% CI = 0.071, 1.340) and higher odds of central obesity ranging from 1.055 (95% CI = 1.000, 1.109) to 1.167 (95% CI = 1.037, 1.298). When the continuous exposure (each 10 dB(A) increase in noise) was introduced, similar results were found. This study indicated positive associations of traffic noise with WC and central obesity. However, in consideration of some limitations, there is an urgent need for future studies to increase the sample size, discriminate the etiological differences in different noise and obesity indicators, and thoroughly consider socioeconomic status.

Fecal microbiota relationships with childhood obesity: A scoping comprehensive review

Childhood obesity is a costly burden in most regions with relevant and adverse long-term health consequences in adult life. Several studies have associated excessive body weight with a specific profile of gut microbiota. Different factors related to fecal microorganism abundance seem to contribute to childhood obesity, such as gestational weight gain, perinatal diet, antibiotic administration to the mother and/or child, birth delivery, and feeding patterns, among others. This review reports and discusses diverse factors that affect the infant intestinal microbiota with putative or possible implications on the increase of the obesity childhood rates as well as microbiota shifts associated with excessive body weight in children.

Change in modifiable maternal characteristics and behaviours between consecutive pregnancies and offspring adiposity: A systematic review

Causal evidence links modifiable maternal exposures during the periconceptional period with offspring obesity. The interconception period may be an important time to intervene. We systematically identified studies examining change in modifiable maternal exposures between pregnancies and offspring adiposity. We searched for longitudinal studies published between 1990 and 2019, which included measurements taken on at least two occasions in the period from 1 year prior to the conception of the first birth to the time of the second birth, and which included a measure of adiposity in second, or higher order, siblings. Age, ethnicity and genetics were not considered modifiable; all other factors including length of the interpregnancy interval were. Eleven studies satisfied the inclusion criteria. Higher interpregnancy weight gain or loss, maternal smoking inception, mothers smoking in their first pregnancy and quitting, increasing the number of cigarettes smoked and longer interpregnancy intervals were positively associated with adiposity in second or higher order children. Vaginal birth after caesarean delivery was protective. Further research is needed to ascertain whether the risk of adiposity is fixed based on first pregnancy exposures or if interpregnancy change alters the risk for a subsequent child. This can inform the type and effectiveness of interventions for mothers prior to a subsequent pregnancy.

Early-Life Environmental Exposures and Childhood Obesity: An Exposome-Wide Approach

BACKGROUND

Chemical and nonchemical environmental exposures are increasingly suspected to influence the development of obesity, especially during early life, but studies mostly consider single exposure groups.

OBJECTIVES

Our study aimed to systematically assess the association between a wide array of early-life environmental exposures and childhood obesity, using an exposome-wide approach.

METHODS

The HELIX (Human Early Life Exposome) study measured child body mass index (BMI), waist circumference, skinfold thickness, and body fat mass in 1,301 children from six European birth cohorts age 6-11 y. We estimated 77 prenatal exposures and 96 childhood exposures (cross-sectionally), including indoor and outdoor air pollutants, built environment, green spaces, tobacco smoking, and biomarkers of chemical pollutants (persistent organic pollutants, metals, phthalates, phenols, and pesticides). We used an exposure-wide association study (ExWAS) to screen all exposure-outcome associations independently and used the deletion-substitution-addition (DSA) variable selection algorithm to build a final multiexposure model.

RESULTS

The prevalence of overweight and obesity combined was 28.8%. Maternal smoking was the only prenatal exposure variable associated with higher child BMI (z-score increase of 0.28, 95% confidence interval: 0.09, 0.48, for active vs. no smoking). For childhood exposures, the multiexposure model identified particulate and nitrogen dioxide air pollution inside the home, urine cotinine levels indicative of secondhand smoke exposure, and residence in more densely populated areas and in areas with fewer facilities to be associated with increased child BMI. Child blood levels of copper and cesium were associated with higher BMI, and levels of organochlorine pollutants, cobalt, and molybdenum were associated with lower BMI. Similar results were found for the other adiposity outcomes.

DISCUSSION

This first comprehensive and systematic analysis of many suspected environmental obesogens strengthens evidence for an association of smoking, air pollution exposure, and characteristics of the built environment with childhood obesity risk. Cross-sectional biomarker results may suffer from reverse causality bias, whereby obesity status influenced the biomarker concentration. https://doi.org/10.1289/EHP5975.

Are environmental area characteristics at birth associated with overweight and obesity in school-aged children? Findings from the SLOPE (Studying Lifecourse Obesity PrEdictors) population-based cohort in the south of England

BACKGROUND

Geographical inequalities in overweight and obesity prevalence among children are well established in cross-sectional research. We aimed to examine how environmental area characteristics at birth are related to these outcomes in childhood.

METHODS

Anonymised antenatal and birth data recorded by University Hospital Southampton linked to school-measured weight and height data for children within Southampton, UK, were utilised (14,084 children at ages 4-5 and 5637 at ages 10-11). Children's home address at birth was analysed at the Lower and Middle layer Super Output Area (LSOA/MSOA) levels (areas with average populations of 1500 and 7000, respectively). Area-level indices (walkability, relative density of unhealthy food outlets, spaces for social interaction), natural greenspace coverage, supermarket density and measures of air pollution (PM_2.5, PM₁₀ and NO_x) were constructed using ArcGIS Network Analyst. Overweight/obesity was defined as a body mass index (BMI; kg/m²) greater than the 85th centile for sex and age. Population-average generalised estimating equations estimated the risk of being overweight/obese for children at both time points. Confounders included maternal BMI and smoking in early pregnancy, education, ethnicity and parity. We also examined associations for a subgroup of children who moved residence between birth and outcome measurement.

RESULTS

There were mixed results between area characteristics at birth and overweight/obesity at later ages. MSOA relative density of unhealthy food outlets and PM₁₀ were positively associated with overweight/obesity, but not among children who moved. LSOA greenspace coverage was negatively associated with the risk of being overweight/obese at ages 10-11 in all children (relative risk ratio 0.997, 95% confidence interval 0.995-0.999, p = 0.02) and among children who moved.

CONCLUSIONS

Local access to natural greenspaces at the time of birth was inversely associated with becoming overweight or obese by age 10-11, regardless of migration. Increased access/protection of greenspace may have a role in the early prevention of childhood obesity.

How Birth Season Affects Vulnerability to the Effect of Ambient Ozone Exposure on the Disease Burden of Hypertension in the Elderly Population in a Coastal City in South China

Birth season is an important factor that reflects prenatal nutritional conditions during early development, and which might have lifelong impacts on health. Moreover, ambient ozone pollution has been considered an important environmental risk factor for hypertension. However, whether birth season affects vulnerability to the effect of ambient ozone exposure on late-life hypertension is still unknown. A flexible case–crossover design was used to explore the effect of ambient ozone exposure on the disease burden of hypertension using years of life lost (YLL) in the elderly population in a coastal city in South China from 2013 to 2016. The influence of birth season was also explored. Ozone exposure was significantly associated with increased YLL from hypertension. The association was higher in the elderly individuals who were born in autumn than in those born in other seasons. Specifically, every 10 μg/m³ increase in ozone was associated with 0.68 (95% CI: 0.27, 1.10) YLL from hypertension in the elderly population born in autumn, while nonsignificant associations were found for those born in other seasons. The birth season, which affects the nutritional condition during early development, could affect vulnerability to the effect of ambient ozone exposure on the disease burden of hypertension in late life. The findings highlighted the importance of taking birth season into consideration when exploring the hypertensive effects of ozone exposure.

Maternal and early-life area-level characteristics and childhood adiposity: A systematic review

There is a cross-sectional evidence that physical and social environments are linked to childhood adiposity. Evidence is scarce for the role of preconception, pregnancy, and early-life area-level characteristics in shaping childhood adiposity. We aimed to systematically review evidence for associations between physical and social environmental conditions experienced in these periods and childhood adiposity. Published literature was identified from the CINAHL, Embase, MEDLINE, and PsycINFO databases. Longitudinal studies linking an area-level environmental exposure in the preconception, pregnancy, or early-life (less than 1 year) periods and a measure of adiposity between the ages of 2 and 12 years were examined. Eight studies in the United States, Denmark, South Korea, United Kingdom, and Canada satisfied the inclusion criteria. Storm-induced maternal stress, nitrogen oxides exposure, traffic noise, and proximity were associated with greater childhood adiposity. Frequent neighbourhood disturbances were associated with lower adiposity, while particulate matter exposure was associated with both higher and lower adiposity in childhood. Area-level characteristics may play a role in the ongoing obesity epidemic. There is a limited evidence of longitudinal associations between preconception, pregnancy, and early-life area-level characteristics with childhood adiposity. Numerous factors that appear important in cross-sectional research have yet to be assessed longitudinally, both individually and in combination.