Effect of Tacrolimus Versus Cyclosporine on Glucose Metabolism of Pancreas and Kidney Recipients in the Late (> 8 years) Posttransplant Period

Abstract

Diabetogenic effects of immunosuppressive agents are of great importance in pancreas or islet transplantation. The aim of our study was to compare the glucose metabolism in type 1 diabetic kidney and pancreas recipients on tacrolimus (Tacro) versus cyclosporine-based (Cyclo) immunosuppression in the late posttransplant period. We examined 26 insulin-independent patients with stabile good renal function. They were at least 7 years after simultaneous pancreas and kidney transplantation and with unchanged immunosuppressive therapy for at least 6 years. The mean follow-up in Tacro (n = 13) and Cyclo (n = 13) groups were 9.7 ± 1.9 and 10.9 ± 1.3 years, respectively ( P = .08). Fasting glycemia, insulin levels, glycosylated hemoglobin (HbA 1c), a standard intravenous glucose tolerance test (IVGTT) with coefficient of glucose assimilation (K G) calculation and trough Tacro/Cyclo levels were assessed. Insulin sensitivity and insulin secretion were evaluated using the homeostasis model assessment (HOMA-IR, HOMA-B). Total C-peptide and insulin secretions were calculated as areas under the curves (AUC) from the serum levels during the IVGTT. Tacro and Cyclo groups did not differ in age and body mass index. We did not find any significant difference in any examined parameters of glucose metabolism (fasting glycemia, insulin and C-peptide levels, HbA 1c, IVGTT with K G, HOMA-IR, HOMA-B, AUC of C-peptide and AUC of insulin; P > .05). Two patients in the Tacro group and none in the Cyclo group had K G <0.8%/min. Seven recipients in the Tacro group and eight in the Cyclo group had the normal glucose tolerance with K G ≥ 1.2%/min. Trough Tacro or Cyclo levels did not correlate with any of examined parameters. The use of different types of calcineurin inhibitors in type 1 diabetic pancreas and kidney recipients had no effect on glucose metabolism in the late posttransplant period.