Clinical Heterogeneity of Pregnant, Obese, Non-Insulin-Dependent Diabetic Women: Evidence for Identification of Syndrome X and Onset of NIDDM at a Young Age

We have prospectively studied 148 pregnant women with the heterogeneous syndrome of non-insulin-dependent diabetes mellitus (NIDDM) during the decade 1978-1988. The group was predominantly Mexican American, older, and heavier than insulin-dependent diabetes mellitus. Fasting C-pep-tide (C-P) levels were higher vs. IDDM (P = 0.000) and vs. normals (P < 0.03). C-P areas under the curve of a 400-kcal 2-h breakfast meal tolerance test were significantly elevated (NIDDM vs. IDDM, P = 0.000; vs. normals, P < 0.003). Mean fasting triglyceride (TG) values were 320 ± SD 154 mg/dl in 72 NIDDM vs. 237 ± SD 77 mg/dl in 33 normals (P < 0.000) who did not differ from well controlled IDDM. Seventeen percent of NIDDM had fasting TG levels > 400 mg/dl. Exogenous insulin doses in NIDDM varied from 10-333 units a day. A subset of 14 women was identified with features of an insulin resistance syndrome (upper trunk obesity, hypertriglyceridemia, hypertension antedating pregnancy, and insulin resistance). An additional 15 women age 15-24 years were identified with early onset NIDDM or possibly maturity onset diabetes of the young (MODY). We concluded that 1) NIDDM is a common problem during gestation, 2) the disorder is heterogeneous and, 3) identification is important for diabetes management during pregnancy and initiation of intervention measures for risk factors to prevent serious complications in later life.