Impact of DHA/Oat on Metabolic Health in Gestational Diabetes Mellitus

DHA is a long-chain fatty acid that has been shown to increase insulin sensitivity in basic science studies. Some studies have reported that oat (β-glucan) intake in patients with type 2 diabetes may improve glycaemic control. Evidence is emerging that gut microbiota may play an important role in energy homeostasis and glucose metabolism. This RCT aims to test the hypothesis that DHA and/or oat intake may improve glycemic control in women with gestational diabetes mellitus (GDM), and may impact metabolic health in fetuses/infants as indicated by cord blood leptin level. Changes in microbiota may be linked to these effects.

Growing evidence suggests that epigenetic changes may occur during fetal development in response to an adverse in utero environment, and this may "program" the risk of metabolic syndrome and type 2 diabetes in adulthood. GDM's offspring are programmed to be at substantially elevated risk of metabolic syndrome and type 2 diabetes in adulthood. We will explore whether the intervention may affect epigenetic profile in placental DNA in GDM.

Pregnant women bearing a singleton fetus without any evidence of malformation and with a de novo diagnosis of GDM at 22-28 weeks of gestation will be randomized into four arms: DHA, oat, oat plus DHA, and placebo. We will collect maternal blood and stool specimens on recruitment and 8-weeks post-intervention, cord blood and placenta specimens at delivery. The primary outcomes are cord blood leptin concentration in the baby, and fasting blood glucose at the 8 weeks post-intervention in the mother.