Profiling circulating microRNAs in pregnancies complicated by type 1 diabetes, type 2 diabetes and gestational diabetes mellitus

Maternal diabetes is associated with complications for both mother and child. Mothers have an increased risk of hypertension and caesarean section, while the risk of macrosomia, hypoglycaemia, respiratory distress syndrome, preterm delivery, malformations, and mortality is increased in children. Moreover, both mothers and children have a life-long risk of developing type 2 diabetes (T2DM) and cardiovascular disorders in future. Evidence suggests that women with pregestational type 1 diabetes (T1DM) and T2DM have a greater risk of complications compared to women with gestational diabetes mellitus (GDM), although the mechanisms that link maternal diabetes type with adverse outcomes are not elucidated. In recent years, epigenetic mechanisms, such as microRNAs (miRNAs), have emerged as key players in the pathophysiology of pregnancy complications. The aim of this study was to assess the effect of maternal diabetes type on circulating miRNA expression. Demographic information and serum were obtained from pregnant women with T1DM (n=6), T2DM (n=26), GDM (n=17) and normoglycaemia (n=24) at 16-27 weeks of gestation. C-peptide, total and high molecular weight (HMW) adiponectin, triglycerides and C-reactive protein (CRP) concentrations were measured using enzyme-linked immunosorbent assays. Serum miRNAs were profiled using the Human Serum/Plasma miScript miRNA PCR array (n=4 per group). Women with T2DM (p=0.04) and GDM (p=0.015) were older than women with T1DM. Glucose concentrations were higher in women with maternal diabetes compared to normoglycaemia (p