Increased resistin blood levels are not associated with insulin resistance in patients with renal disease

Abstract

Background:Resistin is a newly discovered insulin inhibitor secreted by adipocytes. We explored the potential role of resistin in the pathophysiological process of insulin resistance encountered in patients with renal disease. Methods:Resistin blood concentrations, insulin sensitivity index (by intravenous glucose tolerance test), and glomerular filtration rate (GFR; by inulin clearance) were assessed in 30 male patients with immunoglobulin A glomerulonephritis in different stages of renal disease. Results:Patients with increased resistin blood concentrations had more advanced renal failure and were significantly older. Plasma resistin levels correlated significantly with GFR (r = −0.82; P < 0.0001), plasma homocysteine concentration (r = 0.68; P < 0.001), and age (r = 0.42; P = 0.05), but not with fasted plasma insulin (r = −0.34; P = 0.12), glucose (r = 0.25; P = 0.19), and leptin (r = −0.24; P = 0.21) concentrations; body mass index (r = −0.06; P = 0.75), waist-hip ratio (r = 0.09; P = 0.63), or insulin sensitivity (r = −0.05; P = 0.79). In multiple regression analysis, GFR was the only independent predictor of plasma resistin concentrations in renal patients (r = −0.812; P < 0.0001). Conclusion:Resistin blood concentrations increase with progressive impairment of renal function. Thus, the kidney seems to be an important site of resistin elimination. However, the greater than 5-fold increase in resistin blood levels apparently is not associated with deterioration in insulin sensitivity in patients with renal disease.