Effects of Conversion From a Twice-Daily Tacrolimus to a Once-Daily Tacrolimus on Glucose Metabolism in Stable Kidney Transplant Recipients

Introduction. The adverse effects of tacrolimus are known to play major roles in new-onset diabetes after transplantation. The purpose of this study was to investigate the effects of conversion from a twice-daily tacrolimus (Tac-BID) to a once-daily tacrolimus (Tac-OD) on glucose metabolism in stable kidney transplant recipients. Patients and methods. Twenty-six patients were converted from Tac-BID to Tac-OD on a 1:1 mg basis and examined for its effects on glucose metabolism. Unless rejection or tacrolimus toxicity was suspected, we did not perform dose adjustments of Tac-OD or reconversion to Tac-BID until 4 weeks after conversion. Subsequent dose adjustments were allowed to maintain tacrolimus target trough concentration within the. Changes in clinical parameters were compared between baseline and 24 weeks after conversion. Results. Conversion from Tac-BID to Tac-OD on a 1:1 mg basis resulted in a significant decrease in tacrolimus trough level at 4 weeks after conversion. Because dose adjustments were performed, the trough level did not differ significantly between baseline and 24 weeks after conversion. At 4 and 24 weeks after conversion, the homeostasis model assessment of pancreas beta-cell function (HOMA-beta) increased significantly. Conclusions. Although there was no change in tacrolimus trough level between baseline and 24 weeks after transplantation, HOMA-beta at 24 weeks after conversion was significantly higher than that at baseline. These results indicated that conversion from Tac-BID to Tac-OD may improve pancreas beta-cell function in kidney transplant recipients.