Contribution of visceral adiposity and insulin resistance to metabolic risk factors in Japanese men.

We investigated the relative impacts of visceral adiposity and insulin resistance on the metabolic risk profile in middle-aged Japanese men. A cross-sectional study was conducted in 636 nondiabetic Japanese men with a mean age of 51.6 years. Visceral adipose tissue (AT) was assessed using computed tomography, and insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR). Metabolic risk factors were diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome criteria: (1) hypertriglyceridemia, (2) low high-density lipoprotein cholesterol, (3) hypertension, (4) impaired fasting glucose, and (5) impaired glucose tolerance. Visceral AT and HOMA-IR were significantly and positively correlated with each other (r = 0.41, P < .001). Using the 75th percentile value as a cut point, those with isolated large visceral AT showed significantly greater odds ratios for each of the 5 risk factors measured except impaired fasting glucose, whereas those with isolated high HOMA-IR showed significantly greater odds ratios for each of the 5 risk factors except hypertriglyceridemia and impaired glucose tolerance, compared with the control group. The combined group (increased visceral AT and HOMA-IR) had the highest odds ratios for all studied risk factors. On logistic regression analysis using visceral AT and HOMA-IR as continuous independent variables, they were each independently associated with most of the metabolic risk factors and their clustering. In conclusion, neither visceral AT nor HOMA-IR stands out as the sole driving force of the risk profile; each makes a significant contribution to metabolic abnormalities in Japanese men.