Title Contribution of visceral adiposity and insulin resistance to metabolic

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 insulin resistance (HOMA-IR). Metabolic risk factors were diagnosed according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel III metabolic syndrome criteria: (1) hypertriglyceridemia, 2) low high-density-lipoprotein cholesterol, 3) hypertension, 4) impaired fasting glucose (IFG), and 5) impaired glucose tolerance (IGT). Visceral AT and HOMA-IR were significantly and positively correlated with each other (r=0.41, p<0.001). Using the 75 percentile value as a cut-point, those with isolated large visceral AT showed significantly greater odds ratios for each of the five risk factors measured except IFG, while those with isolated high HOMA-IR showed significantly greater odds ratios for each of the five risk factors except hypertriglyceridemia and IGT compared to 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.