Posttransplant diabetes mellitus in kidney allograft recipients: incidence, risk factors, and management.

Background: Posttransplant diabetes mellitus (PTDM), associated with the use of immunosuppressants, occurs at varying rates in kidney transplant recipients.

Methods: Five transplant centers conducted a retrospective review of 435 kidney recipients completing at least 6 months of follow-up to determine risk factors, incidence, and management strategies for posttransplant glucose intolerance. A distinction was made between hyperglycemia and diabetes.

Results: The incidence of PTDM was found to be 4.9%. Among tacrolimus-treated patients it was 5.7%, compared with 3.3% among cyclosporine-treated patients (P=0.453). Mean daily maintenance doses of prednisone and mycophenolate mofetil (MMF) were significantly lower in tacrolimus-treated patients. Significantly more tacrolimus-treated patients were prednisone-free (9.0%/0%; P<0.001). Logistic regression analysis revealed that the absence of an antiproliferative agent correlated with the development of PTDM (odds ratio=3.56; P=0.01).

Conclusions: Based on this study, we propose management guidelines specifically for glucose intolerance developing after renal transplantation. Maintenance of blood glucose levels within strict limits is recommended, and the contribution of immunosuppressive agents to the development of PTDM is accounted for. Gradual tapering of prednisone and tacrolimus is proposed for patients who develop PTDM but also bear minimal risk of rejection. Tapering and eventual withdrawal of insulin should be attempted once blood glucose levels normalize. Switching to the alternative calcineurin inhibitor should only be considered as a late intervention. Tacrolimus therapy should be considered even in patients at high risk for diabetes, because the benefit of reduced acute rejection incidence and severity, as demonstrated in other studies, outweighs the risk of PTDM.