PLASMA-LIPOPROTEINS AND INCIDENCE OF NON-INSULIN-DEPENDENT DIABETES-MELLITUS IN PIMA-INDIANS - PROTECTIVE EFFECT OF HDL CHOLESTEROL IN WOMEN

The role of plasma lipoproteins in the development of non-insulin-depe ndent diabetes mellitus (NIDDM) was studied in 787 non-diabetic (2-h g lucose < 11.1 mmol/l) Pima Indians (265 men and 522 women). Subjects w ere followed for a mean of 9.8 (range: 1.8-16.4) years, during which 2 61 (76 men and 185 women) developed NIDDM. In men and women, very-low- density lipoprotein (VLDL) cholesterol, VLDL triglyceride, low-density lipoprotein triglyceride and total triglyceride, controlled for age, predicted NIDDM (P < 0.01 for each). These effects diminished when con trolled for age, sex, body mass index, systolic blood pressure and 2-h glucose. However, high-density lipoprotein (HDL) cholesterol, control led for age, body mass index, systolic blood pressure and 2-h glucose, was a significant protective factor for NIDDM in women (hazard rate r atio (HRR) = 0.35, 95% CI (0.23-0.54), P < 0.001, 90th compared with 1 0th percentile) but not in men (HRR = 1.04, 95% CI (0.53-2.05), P = 0. 915). This association remained significant in women when controlled f or fasting or 2-h plasma insulin concentrations, other estimates of in sulin resistance or alcohol consumption. The protective effect of HDL cholesterol was similar among women with normal (2-h glucose < 7.8 mmo l/l) or impaired (7.8 mmol/l less than or equal to 2-h glucose < 11.1 mmol/l) glucose tolerance at baseline. These results indicate that lip oprotein disorders are an early accompaniment of the abnormalities tha t lead to NIDDM.