Maternal overnutrition impairs offspring's insulin sensitivity: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to investigate the association between maternal overnutrition and offspring's insulin sensitivity-following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Studies published in English before April 22, 2019, were identified through searches of four medical databases. After selection, 15 studies aiming to explore the association between prepregnancy body mass index (ppBMI) or gestational weight gain (GWG) of non-diabetic mothers and their offspring's insulin sensitivity (fasting insulin or glucose level and Homeostatic Measurement Assessment for Insulin Resistance [HOMA-IR]) were included in the meta-analysis. Associations of ppBMI and GWG with offspring's insulin sensitivity were analysed by pooling regression coefficients or standardized differences in means with 95% confidence intervals (CIs). Maternal ppBMI showed significant positive correlations with the level of both fasting insulin and HOMA-IR in offspring (standardized regression coefficient for fasting insulin: 0.107, CI [0.053, 0.160],p< 0.001 and that for HOMA-IR: 0.063, CI [0.006, 0.121],p= 0.031). However, the result of the analysis on coefficients adjusted for offspring's actual anthropometry (BMI and adiposity) was not significant. Independent from ppBMI, GWG tended to show a positive correlation with insulin level, but not after adjustment for offspring's anthropometry. Offspring of mothers with excessive GWG showed significantly higher HOMA-IR than those of mothers with optimal GWG (p= 0.004). Our results demonstrate that both higher ppBMI and GWG increase the risk of offspring's insulin resistance, but the effect of ppBMI on insulin sensitivity in offspring may develop as consequence of their adiposity.