Effects of Cyclosporin A and Low Dosages of Steroid on Posttransplantation Diabetes in Kidney Transplant Recipients

OBJECTIVE: To investigate the adverse effects of cyclosporin A (CsA) on pancreatic beta-cell function in kidney transplant recipients. RESEARCH DESIGN AND METHODS: The study consisted of 73 patients without a history of diabetes mellitus who had undergone kidney transplantation in our clinic. RESULTS: We experienced a higher incidence of posttransplantation diabetes mellitus (PTDM) in patients receiving CsA and low dosages of methylprednisolone (6/20, 30%, P less than 0.05) than in patients receiving conventional therapy of azathioprine methylprednisolone (4/53, 7.5%) since the introduction of CsA. In all 6 patients in the CsA-treated group, PTDM occurred within 3 mo after transplantation. The CsA level during the initial 3 mo posttransplant was significantly higher in diabetic than nondiabetic subjects, and the highest CsA level was observed shortly (1 mo) before the development of PTDM. After an average of 71 days of insulin therapy, there was complete remission of PTDM in 5 of 6 diabetic patients, with a corresponding decrease in CsA level. For the patients who were in remission for greater than 1 yr, a significant improvement of glucose intolerance was observed in association with a significantly higher insulin response to oral glucose load; however, their glycemic profile still showed a significantly higher plasma glucose concentration and a prolonged continuous elevation without initial peak of the insulin-response curve in contrast to the normal pattern found in nondiabetic subjects in the CsA-treated group. CONCLUSIONS: This study suggests that CsA in combination with low dosages of steroid may have adverse effects on glucose metabolism, which may lead to effects similar to those in non-insulin-dependent diabetes mellitus.