Prenatal Stress, Methylation in Inflammation-Related Genes, and Adiposity Measures in Early Childhood: the Programming Research in Obesity, Growth Environment and Social Stress Cohort Study
Maternal stress during pregnancy may influence childhood growth and adiposity, possibly through immune/inflammatory programming. We investigated whether exposure to prenatal stress and methylation in inflammation-related genes were associated with childhood adiposity in 424 mother-child pairs in Mexico City, Mexico.Methods
A stress index was created based on four prenatally administered stress-related scales (Exposure to Violence, Crisis in Family Systems, State-Trait Anxiety Inventory, and Edinburgh Postnatal Depression Scale). We measured weight, height, body fat mass (BFM), percentage body fat (PBF), and waist circumference in early childhood (age range, 4–6 years). Body mass index (BMI) z scores were calculated according to World Health Organization standards. DNA methylation in gene promoters of tumor necrosis factor α, interleukin 8, and interleukin 6 (IL6) in umbilical cord blood were determined by pyrosequencing.Results
An interquartile range increase in stress index (27.3) was associated with decreases of 0.14 unit in BMI z score (95% confidence interval [CI] = −0.28 to −0.005), 5.6% in BFM (95% CI = −9.7 to −1.4), 3.5% in PBF (95% CI = −6.3 to −0.5), and 1.2% in waist circumference (95% CI = −2.4 to −0.04) in multivariable-adjusted models. An interquartile range increase in IL6 methylation (3.9%) was associated with increases of 0.23 unit in BMI z score (95% CI = 0.06–0.40), 8.1% (95% CI = 2.3–14.3) in BFM, 5.5% (95% CI = 1.7–9.5) in PBF, and 1.7% (95% CI = 0.2–3.3) in waist circumference.Conclusions
Prenatal stress was associated with decreased childhood adiposity, whereas cord blood IL6 methylation was associated with increased childhood adiposity in Mexican children.