Since there is evidence that fat distribution is a better predictor of cardiovascular disease than the degree of obesity, some risk factors for atherosclerosis have been evaluated in middle age Type II male diabetics and in obese subjects with and without glucose intolerance. In non-insulin-dependent diabetics (NIDD), abdominal obesity reflected by the waist/hip-circumference ratio (WHR) is related to parameters of metabolic control, lipid parameters, insulin status and response, hypertension, and vascular complications. High WHR is associated with: (a) significantly (p less than 0.01) higher HbA1 values than in the group without abdominal fat distribution; (b) a highly significant (p less than 0.001) negative correlation with high-density-lipoprotein cholesterol (HDL-C) and a positive correlation with the total/HDL-C ratio, which remains after correction for the body mass index; (c) higher apolipoprotein B concentrations; and (d) an elevated atherogenic index. Both fasting and postprandial insulin and C-peptide values may be a link between abdominal fat deposits and metabolic disturbances. Obese patients with upper body fat accumulation have significantly lower HDL-C levels, and a higher prevalence of glucose intolerance and diabetes than do patients with lower body fat obesity. Fasting glycemia, insulin, and the insulin area under the curve during an oral glucose load are significantly (p less than 0.005) increased in those with the greatest WHR, which is similar to that in NIDD and central obesity. An excess of abdominally located fat, even without manifest obesity, is associated with metabolic disturbances that indicate increased risk of atherogenesis and of higher morbidity and mortality, which may be due to characteristics of abdominally located adipocytes.