In a recent elegant study, 62 postmenopausal women with normal glucose tolerance (normal) were compared with 33 postmenopausal women with impaired glucose tolerance (IGT) and 18 women with type 2 diabetes (T2D) . Women were further divided according to the status of the visceral abdominal fat. The contribution of glucose tolerance status and intra-abdominal fat to cardiovascular disease (CVD) risk was investigated, with subcutaneous and intra-abdominal adipose tissue measured by CT scan and insulin sensitivity measured by the euglycemic hyperinsulinemic clamp method. Compared with normal women having low amounts of visceral adipose tissue (lowest risk group), women with T2D, women with IGT plus high amounts of visceral adipose tissue and normal women with high amounts of visceral adipose tissue demonstrated a worse risk profile: they had lower insulin sensitivity, higher triglyceride levels, higher levels of high-sensitivity C-reactive protein (hsCRP) and lower levels of HDL2 cholesterol. Women with IGT and high levels of visceral adipose tissue had similar lipid–lipoprotein profiles and inflammatory marker levels when compared with normal women having a similar amount of visceral adipose tissue. These findings suggest that greater levels of visceral adipose tissue contribute independently to dyslipidemia and low-grade inflammation. Furthermore, normal women having higher amounts of visceral fat had similar levels of hsCRP and IL-6 to those in women with T2D, again indicative of visceral fat contributing to chronic low-grade inflammation independently of glucose tolerance status. The overall study findings suggest that, in women without T2D, the accumulation of intra-abdominal fat makes a substantial contribution to the deterioration of their CVD risk profile.
Director, the Womens Health Research Program, School of Public Health and Preventive Medicine, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia