A Comparison of Novel and Commonly-Used Indices of Insulin Sensitivity in African American Chronic Hemodialysis Patients

Background Insulin resistance (IR) is highly prevalent in chronic hemodialysis (CHD) patients and is associated with poor cardiovascular outcomes. Hyperinsulinemic euglycemic glucose clamp (HEGC) is the gold standard for measuring IR. The comparison of commonly-used indirect indices of IR to HEGC has not been adequately performed in this population. Furthermore, the validity of newly proposed adipokine-based IR indices has not been explored. Design, setting, participants, & measurements This is an observational study performed in a single center, involving 12 prevalent CHD patients (50 +/- 9 years old, 100% African American, 33% women, body mass index of 34.4 +/- 7.6 kg/m(2)) who were studied three consecutive times. IR was assessed by HEGC (glucose-disposal rate [GDR]), homeostatic model assessment of IR (HOMA-IR), HOMA-IR corrected by adiponectin (HOMA-AD), leptin adiponectin ratio (LAR), QUICKI, and the McAuley's index at each time point. Results Eighty-three percent of the subjects displayed either glucose intolerance or overt insulin resistance by HEGC (GDR median, 5.71; interquartile range [IQR], 4.16, 6.81). LAR and HOMA-AD were the best correlates of IR measured by HEGC (r = -0.72, P < 0.001, and 0.67, P < 0.001), respectively. Fat percentage, interleukin-6, and adipokines (leptin, adiponectin, and resistin) were strongly associated with GDR. HEGC, LAR, and HOMA-AD had the best intraclass correlation coefficients. Conclusion IR is common in CHD patients. Adipokine-based indices are the best correlates of IR measurements by HEGC. HOMA-IR and QUICK' are reasonable alternatives. Use of these indices may allow better detection of alterations in insulin sensitivity in CHD patients. Clin J Am Soc Nephrol 6: 767-774, 2011. doi: 10.2215/CJN.08070910