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 β-cell function (HOMA-β) increased significantly.

Conclusions: Although there was no change in tacrolimus trough level between baseline and 24 weeks after transplantation, HOMA-β 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 β-cell function in kidney transplant recipients.