Foetal hyperinsulinaemia and increased fat mass correlate negatively with circulating fatty acid concentrations in neonates of gestational diabetic mothers with dietary-controlled glycaemia

Backgroud Higher accretion of prenatal fat is associated with a higher proportion of obesity in children. However, most of the data on regulatory factors involved in fetal adipogenesis come from animal studies; in humans there is no evidence on how fetal insulin affects fatty acid concentrations and fetal adiposity. Objective We evaluate the relationship between fetal adipose tissue accretion with insulin and fetal consumption of circulating fatty acid (FA). Methods In fasting maternal blood at term and cord samples, from 41 gestational diabetes mellitus women (GDM) and 68 non-diabetic controls, serum compounds were determined. Individual FA were analyzed and expressed as concentrations of FA (mmol/L). Results Both groups had similar maternal serum glucose, insulin, triacylglycerol (TAG), non-esterified FA (NEFA), glycerol and leptin concentrations, but most individual maternal serum FA were lower in GDM than controls. Neonatal fat mass (FM) was higher in the GDM group even though neonatal birth weights were similar. In GDM cord serum glucose, insulin, NEFA and leptin were higher than controls, but glycerol and all individual FA were lower. In GDM neonates only, a negative correlation was found between each FA and FM, and there was a strong negative correlation between the concentrations of umbilical blood insulin and five major FA. Conclusion Our results show for the first time that hyperinsulinemia in fetuses of GDM women increases FA utilization, which may contribute to to their increased adiposity.