Abdominal adiposity and insulin resistance in obese men

We examined the independent relationships among various visceral and abdominal subcutaneous adipose tissue (AT) depots, glucose tolerance, and insulin sensitivity in 89 obese men. Measurements included an oral glucose tolerance test (OGTT), glucose disposal by euglycemic clamp, and abdominal and nonabdominal (e.g., peripheral) AT by magnetic resonance imaging (MRI). OGTT glucose and glucose disposal rates were related (P < 0.05) to visceral AT (r = 0.50 and -0.41, respectively). These observations remained significant (P < 0.05) after control for nonabdominal and abdominal subcutaneous AT, and maximal O(2) consumption (VO(2 max)). Abdominal subcutaneous AT was not a significant correlate (P > 0.05) of any metabolic variable after control for nonabdominal and visceral AT and VO(2 max). Division of abdominal subcutaneous AT into deep and superficial depots and visceral AT into intra- and extraperitoneal AT depots did not alter the observed relationships. Further analysis matched two groups of men for abdominal subcutaneous AT but also for low and high visceral AT. Men with high visceral AT had higher OGTT glucose values and lower glucose disposal rates compared with those with low visceral AT values (P < 0.05). A similar analysis performed on two groups of men matched for visceral AT but also for high and low abdominal subcutaneous AT revealed no statistically different values for any metabolic variable (P > 0.10). In conclusion, visceral AT alone is a strong correlate of insulin resistance independent of nonabdominal and abdominal subcutaneous AT and cardiovascular fitness. Subdivision of visceral and abdominal subcutaneous AT by MRI did not provide additional insight into the relationship between abdominal obesity and metabolic risk in obese men.