The Association between Maternal/Fetal Insulin Receptor Substrate 1 Gene Polymorphism rs1801278 and Gestational Diabetes Mellitus in a Chinese Population

Objectives: Insulin receptor substrate 1 (IRS1) is a crucial factor in the insulin signaling pathway. IRS1 gene polymorphism rs1801278 in mothers has been reported to be associated with gestational diabetes mellitus (GDM). However, it is not clear whether IRS1 gene polymorphism rs1801278 in fetuses is associated with their mothers' GDM morbidity. The purpose of this study is to analyze the association between maternal, fetal, or maternal/fetal IRS1 gene polymorphism rs1801278 and GDM risk. Design: The study was a single-center, prospective cohort study. In total, 213 pairs of GDM mothers/fetuses and 191 pairs of control mothers/fetuses were included in this study. They were recruited after they underwent oral glucose tolerance test during 24-28 weeks of gestation and followed up until delivery. All participants received the conventional interventions (diet and exercise), and no special therapy except routine treatment. Methods: A total of 213 pairs of GDM mothers/fetuses and 191 pairs of normal blood glucose pregnant mothers/fetuses were ge-notyped using PCR and DNA sequencing from January 2015 to September 2016. Maternal/fetal IRS1 gene polymorphism rs1801278 was analyzed and compared between 2 groups. Results: There were no significant differences in the frequency of individual mothers' or fetuses' IRS1 rs1801278 polymorphisms between 2 groups; if both the mothers and fetuses carried A allele, significantly lower GDM morbidity was observed in the mothers. Limitations: The sample size was relatively small as a single-center study. Conclusions: Our study suggested that maternal/fetal rs1801278 polymorphism of IRS1 is a modulating factor in GDM; both mothers/fetuses carrying the A allele of rs1801278 may protect the mothers against the development of GDM.