In this study longitudinal observations of plasma lipo-proteins were made in pregnant diabetic women classified according to the National Diabetes Data Group. Sequential measurements at second trimester (25–27 wk), third trimester (34–37 wk), and 3 mo postpartum (control period) were carried out in 18 diabetic and 6 normal women. In 15 diabetic and 4 normal women from this group, 24-h plasma glucose, serum C-peptide levels, and HbA1c concentrations were measured. Another group of 15 normal and 18 diabetic women underwent determinations of fasting plasma lipoproteine and other parameters at one or more of the test periods.
Insulin-dependent diabetic patients (IDDM, type I) as a group did not differ from normal controls in mean plasma levels of total cholesterol (CHOL), triglyceride (TG), very-low-density lipoprotein triglyceride (VLDL TG), low-density lipoprotein cholesterol (LDL CHOL), high-density lipoprotein cholesterol (HDL CHOL), or ratios of TG:CHOL in LDL or HDL during mid or late pregnancy or 3 mo postpartum. In marked contrast, non-insulin-dependent diabetics (NIDDM, type II) had significantly higher total fasting TG at second trimester (P < 0.005), third trimester (P < 0.03), and postpartum (P < 0.01). VLDL TG levels at the second trimester, third trimester, and postpartum also were higher than in women with IDDM or normals. In NIDDM subjects the accentuated hypertriglyceridemia during second and third trimesters was also apparent in elevated LDL TG:CHOL and HDL TG:CHOL ratios. These differences were not correlated with prepregnancy weight, weight gain during gestation, or diabetic control. Women with gestational diabetes (GDM) also had significantly higher TG levels at second trimester and postpartum. Mean HDL CHOL levels were significantly lower in patients with NIDDM and GDM than in controls and IDDM patients throughout pregnancy and 3 mo postpartum. Two of 21 normals and one woman with IDDM diabetes had spontaneously reversible pregnancy-evoked hypertriglyceridemia.
These results indicate that women with IDDM diabetes do not differ from normal women with respect to pregnancy-associated changes in lipid metabolism. On the other hand, women with NIDDM and GDM exhibit a pregnancy-associated hypertriglyceridemia.