Insulin Resistance After Renal Transplantation

Abstract

OBJECTIVE—The purpose of the present study was to validate various surrogate estimates of insulin sensitivity (IS) in a renal transplant population and to assess the influence of immunosuppressive and antihypertensive therapy on insulin resistance (IR) after renal transplantation. RESEARCH DESIGN AND METHODS—A total of 167 consecutive renal transplant recipients without previously known diabetes underwent a 75-g oral glucose tolerance test (OGTT) 3 months after renal transplantation. A total of 43 patients also underwent a euglycemic-hyperinsulinemic glucose clamp study. Six OGTT-derived IS indexes were validated against the euglycemic-hyperinsulinemic glucose clamp–derived IS index (ISI_CLAMP). RESULTS—The OGTT-derived ISI_TX correlated closely with the ISI_CLAMP (r = 0.58, P < 0.001). The other surrogate estimates of IS were also significantly but less well correlated with the ISI_CLAMP (Spearman’s correlation; r = −0.45 to 0.41, P = 0.003–0.050). In the univariate model, BMI, daily prednisolone dose, creatinine clearance, hypertension, number of antihypertensive agents, and use of diuretics or β-blockers were negatively associated with ISI_TX (P < 0.05). After multiple regression analysis, BMI (P < 0.001), daily prednisolone dose (P < 0.001), cytomegalovirus infection (P = 0.030), and triglycerides (P = 0.034) were shown to be independent predictors of posttransplant IR. CONCLUSIONS—The OGTT-derived ISI_TX may be a useful estimate of IS in Caucasian renal transplant recipients. Increasing daily prednisolone dose is an independent predictor of IR after renal transplantation. Hypertension and the use of β-blockers and diuretics may also deteriorate IR in this group of patients.