Effects of Dipeptidyl Peptidase-4 Inhibitors on Hyperglycemia and Blood Cyclosporine Levels in Renal Transplant Patients with Diabetes: A Pilot Study

BACKGROUND: The use of dipeptidyl peptidase-4 (DPP-4) inhibitors is increasing among renal transplant patients with diabetes. However, the glucose-lowering efficacies of various DPP-4 inhibitors and their effects on blood cyclosporine levels have not been fully investigated. We compared the glucose-lowering efficacies of DPP 4 inhibitors and evaluate their effects on the blood levels of cyclosporine in renal transplant recipients with diabetes. METHODS: Sixty-five renal allograft recipients who received treatment with DPP-4 inhibitors (vildagliptin, sitagliptin, or linagliptin) following kidney transplant were enrolled. The glucose-lowering efficacies of the DPP-4 inhibitors were compared according to the changes in the hemoglobin A1c (HbA1c) levels after 3 months of treatment. Changes in the trough levels of the cyclosporine were also assessed 2 months after treatment with each DPP-4 inhibitor. RESULTS: HbA1c significantly decreased in the linagliptin group in comparison with other DPP-4 inhibitors (vildagliptin -0.38%±1.03%, sitagliptin -0.53%±0.95%, and linagliptin -1.40±1.34; P=0.016). Cyclosporine trough levels were significantly increased in the sitagliptin group compared with vildagliptin group (30.62±81.70 ng/mL vs. -24.22±53.54 ng/mL, P=0.036). Cyclosporine trough levels were minimally changed in patients with linagliptin. CONCLUSION: Linagliptin demonstrates superior glucose-lowering efficacy and minimal effect on cyclosporine trough levels in comparison with other DPP-4 inhibitors in kidney transplant patients with diabetes.