Article Text
Abstract
Background For a given body mass index (BMI) South Asian adults have greater adiposity and are more likely to be insulin resistant compared to European adults. There is evidence that this thin-fat phenotype is present in South Asian children and possibly at birth. Maternal pregnancy exposures associated with developmental overnutrition (BMI, gestational weight gain (GWG), gestational diabetes (GDM) and glucose intolerance), could contribute to ethnic differences and South Asians may be more prone to the effects of overnutrition than other ethnic groups. We examined whether maternal pregnancy exposures are associated with adiposity at age 4/5 in Pakistani and White British children participating in the Born in Bradford (BiB) cohort study.
Methods Born in Bradford is a prospective study of children born to 12,453 mothers between 2007 and 2010 in Bradford, UK. All mothers completed an oral glucose tolerance test in pregnancy. We examined associations between maternal early pregnancy BMI, gestational weight gain (GWG), gestational diabetes (GDM), maternal fasting glucose and maternal postload glucose and height, weight, BMI, subscapular skinfold thickness (SSF) and triceps skinfold thickness (TSF) using data from 3102 Pakistani origin children and 2613 White British children at age 4/5. We adjusted for a range of covariables and multiple imputation was used to increase power and reduce bias.
Results In children of White British women with GDM all measurements were markedly lower compared to children of White British women without GDM. In Pakistani children, GDM was associated with an increase in height and TSF but had minimal effect on weight, BMI and SSF. Increasing fasting glucose reduced all measurements at age 4/5 in White British children except SSF which slightly increased (0.07, 95% CI: −0.13, 0.27). In Pakistani children it slightly reduced all measurements other than height which on average increased by 0.18 (95% CI: −0.08, 0.44) for each mmol/L increase in fasting glucose. Maternal BMI, GWG and postload glucose had a minimal effect on all measurements and this was similar in both ethnic groups.
Conclusion GDM and maternal glucose influence size in childhood but these associations differ between White British and Pakistani origin children. Effects appear stronger and are mostly negative in White British children but are minimal or generally positive in Pakistani origin children.