Elevated lipoprotein lipids and gestational hormones in women with diet-treated gestational diabetes mellitus compared to healthy pregnant controls.

The objective of this study was to describe plasma and lipoprotein perturbations in gestational diabetes mellitus (GDM) compared to controls, and determine if alterations in lipids are related to gestational hormones and/or glucose control. Maternal HbA1c, free fatty acids (FFA), beta-estradiol, progesterone, prolactin, and plasma, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL), HDL2 and HDL3 triglyceride (TG), cholesterol, and dietary intake were determined for women with diet-treated GDM and controls in a longitudinal design. Subjects (N = 25/group) were matched for age, race, and body-mass index (BMI). Women with GDM had significantly higher HbA1c than controls, although both groups were within the normal range (4%-6%). However, body weight gain was less for women with GDM. There was a trend for higher plasma FFAs at 37-38 weeks in GDM versus controls. Plasma and lipoprotein TG among the groups increased over the third trimester, and mean concentrations were greater for women with GDM. In GDM versus controls, VLDL and HDL3 TGs were higher at all times, HDL and HDL2 TGs at 33-34 and 37-38 weeks, and LDL TGs at 37-38 weeks. In VLDL, core lipids (TG + cholesterol) increased over gestation and were greater in GDM. In HDL, the TG/cholesterol ratio was greater in GDM. In GDM versus controls, plasma progesterone and prolactin were higher at all times; beta-estradiol was elevated at 37-38 weeks. HbA1c, progesterone, and prolactin correlated with all lipoprotein TG fractions. Exaggerated hypertriglyceridemia, particularly in the VLDL and HDL fractions, is a feature of GDM. The increase in VLDL TG is likely due to an increase in VLDL synthesis, whereas particle enrichment in TG is a plausible explanation for changes in HDL TG. Slight perturbations in glucose control and gestational hormones in diet-treated GDM may contribute to the observed increase in plasma and lipoprotein TG.