Maternal Gestational Diabetes Mellitus Modifies the Relationship Between Genetically Determined Body Mass Index During Pregnancy and Childhood Obesity

Abstract

ObjectiveTo analyze the interactions between maternal gestational diabetes mellitus (GDM) and genetically determined maternal body mass index (BMI) during pregnancy on offspring childhood obesity. Research Design and MethodsA total of 1114 Chinese mother-child pairs (560 GDM and 554 non-GDM) were included between August 2009 and July 2011. Maternal genetic risk score (GRS) of BMI during pregnancy was derived on the basis of 12 single nucleotide polymorphisms identified from a genome-wide association study. Offspring’s BMI, BMI-for-age z score, weight, weight-for-age z score, waist circumference, sum of skinfolds, and body fat percentage during childhood were measured or calculated. ResultsMaternal GRS of BMI during pregnancy significantly interacted with maternal GDM status on childhood risks of overweight and obesity (all P for interaction <.05). After multivariable adjustment, per unit of GRS was associated with a 24% (P<.001) and a 28% (P<.001) increased risk of overweight and obesity among children of GDM mothers, whereas no significant associations were observed among children of mothers without GDM. In addition, per unit GRS of BMI during pregnancy was significantly associated with 0.16 kg/m2 higher BMI (P=.002), 0.09 higher BMI-for-age z score (P=.002), 0.24 kg higher weight (P=.04), 0.06 higher weight-for-age z score (P=.02), 0.28 cm higher waist circumference (P=.03), 0.94 mm higher sum of skinfolds (P=.004), and 0.37% higher body fat percentage (P=.03) among children of GDM mothers. There were no significant associations between maternal GRS of BMI during pregnancy and offspring’s obesity-related outcomes among children of mothers without GDM. ConclusionOur findings for the first time indicate that maternal GDM status may modify the relation between genetically determined maternal BMI during pregnancy and offspring’s obesity risk during childhood.