High density lipoprotein subfraction 2 (HDL1)-cholesterol level is usually decreased in Type 2 (non-insulin-dependent) diabetes. A study was carried out in 251 Type 2 diabetic patients (106 males [M], 145 females [F]) and in 120 non diabetic controls in order to determine the influence of hypertriglyceridaemia and obesity on the HDL2-cholesterol level and to analyse the relationship between HDL2-cholesterol level and atherosclerosis (coronary heart disease, peripheral atherosclerosis or cerebral vascular disease), in Type 2 diabetes. Influence of hypertriglyceridaemia and obesity on HDL2-cholesterol level was studied by comparing the mean values of HDL2-cholesterol between diabetics and controls, after controlling for hypertriglyceridaemia and obesity, and by a multiple linear regression test. A stepwise logistic regression was performed to analyse the association between the prevalence of atherosclerosis and several variables: age, duration of diabetes, hypertension, cigarette smoking, body mass index, mean glycaemia, total cholesterol, triglyceride, HDL-cholesterol, HDL2-cholesterol and HDL3-cholesterol levels. In both men and women, when both of the factors (hypertriglyceridaemia and obesity) were present of when only one was, HDL2-cholesterol level was significantly lower in the diabetic population, compared with controls. But when obesity and hypertriglyceridaemia were absent, HDL2-cholesterol level, in the diabetic population, was not significantly different from controls (M: 17.9 +/- 13.3 vs 20.5 +/- 13.8 mg/dl: NS; F: 30.1 +/- 21.5 vs 27.6 +/- 14.2 mg/dl: NS).(ABSTRACT TRUNCATED AT 250 WORDS)