The role of prenatal exposures on body fat patterns at 7 years: Intrauterine programming or birthweight effects?

An unwelcome inheritance: childhood obesity after diabetes in pregnancy

Diabetes in pregnancy affects 20 million women per year and is associated with increased risk of obesity in offspring, leading to insulin resistance and cardiometabolic disease. Despite the substantial public health ramifications, relatively little is known about the pathophysiological mechanisms underlying obesity in these high-risk children, which creates a barrier to successful intervention. While maternal glucose itself is undeniably a major stimulus upon intrauterine growth, the degree of offspring hyperinsulinism and disturbed lipid metabolism in mothers and offspring are also likely to be implicated in the disease process. The aim of this review is to summarise current understanding of the pathophysiology of childhood obesity after intrauterine exposure to maternal hyperglycaemia and to highlight possible opportunities for intervention. I present here a new unified hypothesis for the pathophysiology of childhood obesity in infants born to mothers with diabetes, which involves self-perpetuating twin cycles of pancreatic beta cell hyperfunction and altered lipid metabolism, both acutely and chronically upregulated by intrauterine exposure to maternal hyperglycaemia.

Maternal hypertensive disorders in pregnancy and early childhood cardiometabolic risk factors: The Generation R Study

The objective of this study was to determine the associations between hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in the offspring. Therefore, 7794 women from the Generation Rotterdam Study were included, an ongoing population-based prospective birth cohort. Women with a hypertensive disorder of pregnancy were classified as such when they were affected by pregnancy induced hypertension, pre-eclampsia or the haemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome during pregnancy. Early childhood cardiometabolic risk factors were defined as the body mass index at the age of 2, 6, 12, 36 months and 6 years. Additionally, it included systolic blood pressure, diastolic blood pressure, total fat mass, cholesterol, triglycerides, insulin and clustering of cardiometabolic risk factors at 6 years of age. Sex-specific differences in the associations between hypertensive disorders and early childhood cardiometabolic risk factors were investigated. Maternal hypertensive disorders of pregnancy were inversely associated with childhood body mass index at 12 months (confounder model: -0.15 SD, 95% CI -0.27; -0.03) and childhood triglyceride at 6 years of age (confounder model: -0.28 SD, 95% CI -0.45; -0.10). For the association with triglycerides, this was only present in girls. Maternal hypertensive disorders of pregnancy were not associated with childhood body mass index at 2, 6 and 36 months. No associations were observed between maternal hypertensive disorders of pregnancy and systolic blood pressure, diastolic blood pressure, body mass index, fat mass index and cholesterol levels at 6 years of age. Our findings do not support an independent and consistent association between maternal hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in their offspring. However, this does not rule out possible longer term effects of maternal hypertensive disorders of pregnancy on offspring cardiometabolic health.

A Common R219K Variant of ATP-Binding Cassette Transporter A1 Gene Alters Atherometabolic Traits in Pregnant Women With Gestational Diabetes Mellitus

BACKGROUND

ATP-binding cassette transporter A1 (ABCA1) has important roles in high-density lipoprotein (HDL) metabolism and reverse cholesterol transport, and is implicated in lipid-related disorders. Genetic variants are involved in the pathogenesis of gestational diabetes mellitus (GDM). The objective of this study was to investigate the association of rs2230806 (R219K), a single nucleotide polymorphism (SNP) in the lipid-related gene, with the risk of GDM and related traits.

METHODS

The SNP, rs2230806, was genotyped, and clinical and metabolic parameters were determined in 660 GDM patients and 1,097 control subjects. Genetic associations with related traits were also analyzed.

RESULTS

The genotype distributions were similar in GDM patients and normal controls. However, significant differences in the variables examined in the study subjects were noted across the three genotypes. The genotype at the rs2230806 polymorphism was significantly associated with HDL-cholesterol (HDL-C) levels and atherogenic index (AI) values in GDM patients and total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels in control subjects. Subgroup analysis showed that the polymorphism was associated with diastolic blood pressure, in addition to HDL-C levels and AI, in overweight/obese GDM patients, while it was associated with TC levels, AI, pre-pregnancy body mass index (BMI), and BMI at delivery in non-obese GDM patients. In addition, this polymorphism was associated with TC, LDL-C, and apoB levels in overweight/obese control subjects.

CONCLUSIONS

The rs2230806 polymorphism in the ABCA1 gene was associated with variations in atherometabolic traits in GDM patients, with characteristics of BMI dependency, but not with GDM. Our findings highlight a link between related phenotypes in women with GDM and genetic factors.

Effect of early determinants on adolescent fat-free mass: RPS cohort of São Luís - MA

OBJECTIVE

To analyze the effects of early determinants on adolescent fat-free mass.

METHODS

A cohort study with 579 adolescents evaluated at birth and adolescence in a birth cohort in São Luís, Maranhão. In the proposed model, estimated by structural equation modeling, socioeconomic status (SES) at birth, maternal age, pregestational body mass index (BMI), gestational smoking, gestational weight gain, type of delivery, gestational age, sex of the newborn, length and weight at birth, adolescent socioeconomic status, "neither study/nor work" generation, adolescent physical activity level and alcohol consumption were tested as early determinants of adolescent fat-free mass (FFM).

RESULTS

A higher pregestational BMI resulted in higher FFM in adolescence (Standardized Coefficient, SC = 0.152; p < 0.001). Being female implied a lower FFM in adolescence (SC = -0.633; p < 0.001). The negative effect of gender on FFM was direct (SC = -0.523; p < 0.001), but there was an indirect negative effect via physical activity level (SC = -0.085; p < 0.001). Women were less active (p < 0.001). An increase of 0.5 kg (1 Standard Deviation, SD) in birth weight led to a gain of 0.25 kg/m2 (0.106 SD) in adolescent FFM index (p = 0.034). Not studying or working had a negative effect on the adolescent's FFM (SC = -0.106; p = 0.015). Elevation of 1 SD in the adolescent's physical activity level represented an increase of 0.5 kg/m2 (0.207 SD) in FFM index (p < 0.001).

CONCLUSIONS

The early determinants with the greatest effects on adolescent FFM are gender, adolescent physical activity level, pregestational BMI, birth weight and belonging to the "neither-nor" generation.

Evaluating the association of free sugars intake and glycemic load on cardiometabolic outcomes: A prospective analysis throughout adolescence into early adulthood

PURPOSE

To prospectively evaluate the relation of free sugars intake and glycemic load with adiposity and insulin resistance, from adolescence into early adulthood.

METHODS

Data from the population-based cohort EPITeen (Porto, Portugal) at 13 and 21 years old was used (n = 1034). At both ages, dietary assessment was obtained by food frequency questionnaires (FFQ). Added sugar of each food item was estimated based on a systematic methodology described by Louie et al. Free sugars (FS) were defined according to World Health Organization. To each food item of the FFQ, a calculated mean value of FS and glycemic index was assigned. Dietary glycemic load (GL) was determined for each participant. Sex- and age-specific body mass index z-score (BMIz) and waist-to-weight ratio (WWr) were used as measures of adiposity, and the homeostasis model assessment (HOMA-IR) as a measure of insulin resistance. A cross-lagged path analysis was performed to examine causal relationships between FS intake or dietary GL with BMIz, WWr or HOMA-IR.

RESULTS

No significant association was found between intake of FS and dietary GL at 13 years with BMIz, WWr or HOMA-IR at 21. A significant inverse association was found between BMIz at 13 and FS (β = -0.595,95%CI -0.830, -0.359) and dietary GL (β = -0.687,95%CI -0.937,-0.437) at 21 years. Intake of FS, dietary GL, as well as BMIz, WWr and HOMA-IR tracked from 13 to 21 years.

CONCLUSION

No significant association was found between consumption of FS and GL at 13 years with cardiometabolic features at 21 years. Dietary intake and cardiometabolic outcomes tracked from adolescence into early adulthood.

Bidirectional relationships between appetitive behaviours and body mass index in childhood: a cross-lagged analysis in the Generation XXI birth cohort

PURPOSE

Appetitive behaviours have been associated with body mass index (BMI). However, existing data were largely derived from cross-sectional studies and cannot provide insight into the direction of associations. We aimed to explore the bidirectionality of these associations in school-age children.

METHODS

Participants are from the Generation XXI birth cohort, assessed at both 7 and 10 years of age (n = 4264; twins excluded). The Children's Eating Behaviour Questionnaire (CEBQ) was used to measure appetitive behaviours (8 subscales). Anthropometrics were measured and WHO BMI z-score was calculated. Cross-lagged analyses were performed to compare the magnitude and direction of the associations (behaviours at 7 years to BMI z-score at 10 years and the reverse) (covariates: child's sex, physical exercise, maternal age and education; plus BMI z-score at age 7 or, in the reverse direction, the subscale score).

RESULTS

In cross-lagged analyses, appetitive behaviours at 10 years of age (apart from emotional undereating) were shown to be reactive to the child BMI z-score at 7 years of age. Only slowness in eating was significantly related to subsequent BMI. However, the strongest association was from the child BMI z-score to the behaviour (β_standardized = - 0.028 compared with β_standardized = - 0.103, likelihood ratio test p < 0.001).

CONCLUSIONS

BMI at age 7 was related to appetitive behaviours at 10 years of age, rather than the reverse. This suggests that children with a higher BMI in middle childhood are at increased risk of developing an avid appetite over time.

Altered Cortical Brain Structure and Increased Risk for Disease Seen Decades After Perinatal Exposure to Maternal Smoking: A Study of 9000 Adults in the UK Biobank

Secondhand smoke exposure is a major public health risk that is especially harmful to the developing brain, but it is unclear if early exposure affects brain structure during middle age and older adulthood. Here we analyzed brain MRI data from the UK Biobank in a population-based sample of individuals (ages 44-80) who were exposed (n = 2510) or unexposed (n = 6079) to smoking around birth. We used robust statistical models, including quantile regressions, to test the effect of perinatal smoke exposure (PSE) on cortical surface area (SA), thickness, and subcortical volumes. We hypothesized that PSE would be associated with cortical disruption in primary sensory areas compared to unexposed (PSE-) adults. After adjusting for multiple comparisons, SA was significantly lower in the pericalcarine (PCAL), inferior parietal (IPL), and regions of the temporal and frontal cortex of PSE+ adults; these abnormalities were associated with increased risk for several diseases, including circulatory and endocrine conditions. Sensitivity analyses conducted in a hold-out group of healthy participants (exposed, n = 109, unexposed, n = 315) replicated the effect of PSE on SA in the PCAL and IPL. Collectively our results show a negative, long term effect of PSE on sensory cortices that may increase risk for disease later in life.

Adherence to a healthy eating index from pre-school to school age and its associations with sociodemographic and early life factors

Childhood is considered an important period for the development of healthy eating behaviours. This study aimed to evaluate the influence of early life factors and sociodemographic characteristics, including early diet quality, on diet quality at 7 years. The sample includes 5013 children evaluated at the ages of 4 and 7 years from the Portuguese birth cohort Generation XXI with complete information on FFQ. A healthy eating index was developed at both ages to assess adherence to the WHO's dietary recommendations, including eight food groups. Consumption quartiles were obtained for each group at 4 years and assigned a score between 1 and 4. A higher score represents a higher adherence to a better diet (range: 8 to 32). The associations between early life factors and sociodemographic characteristics and the score of the healthy eating index at 7 years were evaluated through linear regression models. The healthy eating index had an average score of 21⋅4 ± 3⋅53 (range: 12 to 32) at 4 years and 20⋅3 ± 3⋅36 (range: 11 to 31) at 7 years. After adjustment for confounders, a positive association was found between the healthy eating index at 4 and 7 years (β = 0⋅384, 95 % CI 0⋅356, 0⋅441). Maternal years of education (β = 0⋅094, 95 % CI 0⋅071, 0⋅116) and dietary score (β = 0⋅182, 95 % CI 0⋅155, 0⋅209) were positively associated with increasing dietary quality from 4 to 7 years. A healthier diet at preschool age, higher maternal education and a healthier diet increase the likelihood of maintaining a high healthy eating index score at school age.

Maternal gestational weight gain and DNA methylation in young women: application of life course mediation methods

AIM

To investigate the role of maternal gestational weight gain (GWG) and prepregnancy BMI on programming offspring DNA methylation.

METHODS

Among 589 adult (age = 32) women participants of the Jerusalem Perinatal Study, we quantified DNA methylation in five candidate genes. We used inverse probability-weighting and parametric g-formula to estimate direct effects of maternal prepregnancy BMI and GWG on methylation.

RESULTS

Higher maternal GWG, but not prepregnancy BMI, was inversely related to offspring ABCA1 methylation (β = -1.1% per quartile; 95% CI: -2.0, -0.3) after accounting for ancestry, parental and offspring exposures. Total and controlled direct effects were nearly identical suggesting included offspring exposures did not mediate this relationship. Results were robust to sensitivity analyses for missing data and model specification.

CONCLUSION

We find some support for epigenetic programming and highlight strengths and limitations of these methods relative to other prevailing approaches.