Impact of cyclosporine and low-dose steroid therapy on insulin sensitivity and beta-cell function in patients with long-term liver grafts

To examine whether factors controlling glucose tolerance, i.e., insulin sensitivity (SI) and first-(phi1) and second-phase insulin secretion (phi2), are impaired in after orthotopic liver transplantation (OLT), they were assesssed in patients that had undergone OLT for cirrhosis (n = 10) with cyclosporin A and low-dose steroid therapy (5 mg prednisone per day) and were compared with those of healthy matched control subjects (n = 10). These factors were determined by means of computer-based analysis of frequently sampled intravenous glucose tolerance tests (FSIGTT). Glucose and insulin profiles (posthepatic insulin) did not differ between both groups, whereas C-peptide levels (prehepatic insulin) were elevated in the transplant group after the FSIGTT, indicating an increased hepatic insulin degradation. SI and (phi1 did not differ between both groups. phi2, however, was significantly enhanced (23.94 +/- 2.63 vs 13.88 +/- 1.25 min(-1), P < 0.05). These results indicate that cyclosporine and low-dose steroid therapy do not impair SI and phi1. However, enhanced phi2 compensates the increased hepatic insulin clearance.