Independent associations of insulin resistance with high whole-body intermuscular and low leg subcutaneous adipose tissue distribution in obese HIV-infected women

Abstract

Background: Obesity and insulin resistance are growing problems in HIV-positive (HIVѿ) women receiving highly active antiretroviral therapy (HAART). Objective: The objective was to determine the contribution of adipose tissue (AT) enlargement and distribution to the presence of insulin resistance in obese HIVѿ women. Design: Whole-body intermuscular AT (IMAT), visceral AT (VAT), subcutaneous AT (SAT), and SAT distribution (leg versus upper body) were measured by whole-body magnetic resonance imaging. Insulin sensitivity (S I ) was measured with an intravenous glucose tolerance test in obese HIVѿ women recruited because of their desire to lose weight (n ҃ 17) and in obese healthy controls (n ҃ 32). Results: The HIVѿ women had relatively less whole-body SAT and more VAT and IMAT than did the controls (P 0.05 for all). A significant interaction by HIV status was observed for the relation of total SAT with S I (P 0.001 for the regression's slope interactions after adjustment for age, height, and weight). However, relations of IMAT, VAT, and SAT distribution (leg SAT as a percentage of total SAT; leg SAT%) with S I did not differ significantly between groups. For both groups combined, the best model predicting a low S I included significant contributions by both high IMAT and low leg SAT%, independent of age, height, and weight, and no interaction between groups was observed (overall r 2 ҃ 0.44, P ҃ 0.0003). Conclusion: In obese HIVѿ women, high whole-body IMAT and low leg SAT% distribution are independently associated with insulin resistance.Am J Clin Nutr 2007;86:100 -6.

Prevalence of insulin resistance and risk of diabetes mellitus in HIV-infected patients receiving current antiretroviral drugs

“…Our study including abdominal fat by DXA in all patients shows that IR is fundamentally associated with the abdominal fat accumulation/trunk obesity (53,54), and not with antiretroviral therapy, HCV coinfection, vitamin D deficiency, CD4C count nadir, or time of HIV infection. In fact, the amount of visceral fat is the main factor for IR and development of diabetes, together with age, in healthy patients, and previous studies linked closely truncal adiposity and increased waist-to-hip ratio with hyperinsulinemia and overt DM (55).…”

Femoral-gluteal subcutaneous and intermuscular adipose tissues have independent and opposing relationships with CVD risk

“…Higher IMAT was significantly associated with the metabolic syndrome in normal weight and overweight, but not in obese men and in women (13). In more African-American than Caucasian nondiabetic women, higher IMAT was found to be an independent predictor of lower insulin sensitivity (2), and we recently reported a strong independent association of IMAT with fasting glucose, independent of VAT in healthy adults (41), and with insulin resistance in HIV+ women (1). The exact mechanisms of IMAT effect on glucose and lipid metabolism are unknown.…”

“…Low amounts of leg SAT combined with high whole body IMAT were found to be independent predictors of insulin resistance in obese HIV+ women (1). The femoral-gluteal adipose tissue (AT) depot is postulated to play a role in the uptake of fatty acids from the circulation and to act as a reservoir for excess triglycerides storage in adipose cells (9).…”

Adipose compartmentalization and insulin resistance among obese HIV-infected women: the role of intermuscular adipose tissue

“…These data highlight the importance of intermuscular adipose tissue accumulation as a critical factor regulating glucose trafficking What is the influence of IMAT on insulin sensitivity among HIV-infected patients? In this issue of the Journal, Albu et al (12) present the results of a cross-sectional study that compared the relation of adipose distribution with insulin resistance in 17 obese HIV-infected women with that in 32 obese but otherwise healthy HIV-negative controls. Whole-body MRI was used to determine SAT, VAT, and whole-body IMAT.…”