Early-life origins of disparities in chronic diseases among Indigenous youth: pathways to recovering health disparities from intergenerational trauma.

Indigenous women and children experience some of the most profound health disparities globally. These disparities are grounded in historical and contemporary trauma secondary to colonial atrocities perpetuated by settler society. The health disparities that exist for chronic diseases may have their origins in early-life exposures that Indigenous women and children face. Mechanistically, there is evidence that these adverse exposures epigenetically modify genes associated with cardiometabolic disease risk. Interventions designed to support a resilient pregnancy and first 1000 days of life should abrogate disparities in early-life socioeconomic status. Breastfeeding, prenatal care and early child education are key targets for governments and health care providers to start addressing current health disparities in cardiometabolic diseases among Indigenous youth. Programmes grounded in cultural safety and co-developed with communities have successfully reduced health disparities. More works of this kind are needed to reduce inequities in cardiometabolic diseases among Indigenous women and children worldwide.

Intensive gestational glycemic management and childhood obesity: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: Hyperglycemia in pregnancy is associated with increased risk of offspring childhood obesity. Treatment reduces macrosomia; however, it is unclear if this effect translates into a reduced risk of childhood obesity. We performed a systematic review and meta-analysis of randomized controlled trials to evaluate the efficacy and safety of intensive glycemic management in pregnancy in preventing childhood obesity. METHODS: We searched MEDLINE, EMBASE, CENTRAL and ClinicalTrials.gov up to February 2016 and conference abstracts from 2010 to 2015. Two reviewers independently identified randomized controlled trials evaluating intensive glycemic management interventions for hyperglycemia in pregnancy and included four of the 383 citations initially identified. Two reviewers independently extracted study data and evaluated internal validity of the studies using the Cochrane Collaboration's Risk of Bias tool. Data were pooled using random-effects models. Statistical heterogeneity was quantified using the I2 test. The primary outcome was age- and sex-adjusted childhood obesity. Secondary outcomes included childhood weight and waist circumference and maternal hypoglycemia during the trial (safety outcome). RESULTS: The four eligible trials (n=767 children) similarly used lifestyle and insulin to manage gestational hyperglycemia, but only two measured offspring obesity and waist circumference and could be pooled for these outcomes. We found no association between intensive gestational glucose management and childhood obesity at 7-10 years of age (relative risk 0.89, 95% confidence interval (CI) 0.65 to 1.22; two trials; n=568 children). Waist circumference also did not differ between treatment and control arms (mean difference, -2.68 cm; 95% CI, -8.17 to 2.81 cm; two trials; n=568 children). CONCLUSIONS: Intensive gestational glycemic management is not associated with reduced childhood obesity in offspring, but randomized data is scarce. Long-term follow-up of trials should be prioritized and comprehensive measures of childhood metabolic risk should be considered as outcomes in future trials.

Diabetes in pregnancy and lung health in offspring: developmental origins of respiratory disease.

Diabetes is an increasingly common complication of pregnancy. In parallel with this trend, a rise in chronic lung disease in children has been observed in recent decades. While several adverse health outcomes associated with exposure to diabetes in utero have been documented in epidemiological and experimental studies, few have examined the impact of diabetes in pregnancy on offspring lung health and respiratory disease. We provide a comprehensive overview of current literature on this topic, finding suggestive evidence that exposure to diabetes in utero may have adverse effects on lung development. Delayed lung maturation and increased risk of respiratory distress syndrome have been consistently observed among infants born to mothers with diabetes and these findings are also observed in some rodent models of diabetes in pregnancy. Further research is needed to confirm and characterize epidemiologic observations that diabetes in pregnancy may predispose offspring to childhood wheezing illness and asthma. Parallel translational studies in human pregnancy cohorts and experimental models are needed to explore the role of fetal programming and other potential biological mechanisms in this context.

Mendelian randomization supports causality between maternal hyperglycemia and epigenetic regulation of leptin gene in newborns.

Leptin is an adipokine that acts in the central nervous system and regulates energy balance. Animal models and human observational studies have suggested that leptin surge in the perinatal period has a critical role in programming long-term risk of obesity. In utero exposure to maternal hyperglycemia has been associated with increased risk of obesity later in life. Epigenetic mechanisms are suspected to be involved in fetal programming of long term metabolic diseases. We investigated whether DNA methylation levels near LEP locus mediate the relation between maternal glycemia and neonatal leptin levels using the 2-step epigenetic Mendelian randomization approach. We used data and samples from up to 485 mother-child dyads from Gen3G, a large prospective population-based cohort. First, we built a genetic risk score to capture maternal glycemia based on 10 known glycemic genetic variants (GRS10) and showed it was an adequate instrumental variable (ß = 0.046 mmol/L of maternal fasting glucose per additional risk allele; SE = 0.007; P = 7.8 × 10(-11); N = 467). A higher GRS10 was associated with lower methylation levels at cg12083122 located near LEP (ß = -0.072 unit per additional risk allele; SE = 0.04; P = 0.05; N = 166). Direction and effect size of association between the instrumental variable GRS10 and methylation at cg12083122 were consistent with the negative association we observed using measured maternal glycemia. Lower DNA methylation levels at cg12083122 were associated with higher cord blood leptin levels (ß = -0.17 log of cord blood leptin per unit; SE = 0.07; P = 0.01; N = 170). Our study supports that maternal glycemia is part of causal pathways influencing offspring leptin epigenetic regulation.