Separate associations between visceral and subcutaneous adipose tissue distribution, insulin and glucose levels in obese women

OBJECTIVE - The primary purpose of this study was to determine the separate associations between visceral (VAT) and subcutaneous adipose tissue (SAT) distribution, skeletal muscle (SM), and plasma insulin and glucose levels, and. A second objective was to determine whether anthropometric methods could be used to identify those women who are at increased metabolic risk. RESEARCH DESIGN AND METHODS - Whole-body SAT, SM, and VAT volume were measured (in liters), using a multislice magnetic resonance imaging (MRI) protocol in 40 premenopausal obese women. Plasma insulin and glucose levels were measured after an overnight fast and in response to a 75-g oral glucose tolerance test (OGTT). RESULTS - With the exception of fasting glucose, VAT was positively correlated with all insulin and glucose variables (P < 0.01). This observation remained true whether VAT was derived from multiple MR images (i.e., VAT volume [in liters]) or from a single MR image (i.e., VAT area [in squared centimeters]). Furthermore, the segmentation of intraperitoneal adipose tissue (portally drained adipose tissue) from VAT did not improve the observed relationships. VAT remained a significant (P < 0.05) correlate of insulin and glucose area after adjusting for either SAT or abdominal SAT (ASAT). SAT, ASAT, and SM volume were not related to any metabolic variable. Waist circumference (WC) was the single strongest anthropometric correlate for fasting insulin and insulin area (P < 0.05). Because it has been reported that disturbances in insulin-glucose homeostasis are more likely associated with a WC value >1 m, in subjects matched for total adiposity, we compared the glucose and insulin area values for those with a WC above (n = 17) and below (n = 15) this value. The group with a WC >1 m had significantly higher values for both insulin and glucose areas (P < 0.05). CONCLUSIONS - The primary observation is that VAT is associated with plasma insulin and glucose variables independent of whole-body SAT, ASAT, and SM in obese women. In addition, the findings provide support for the utility of WC as an anthropometric tool that may be used to identify a subgroup of obese patients at increased metabolic risk.