Tapering off prednisolone and cyclosporin the first year after renal transplantation: the effect on glucose tolerance

Background. Glucose intolerance is an untoward side effect of some immunosu ppressive and anti-hypertensive drugs. The primary aim of the present prosp ective observational study was to test the hypothesis that tapering off pre dnisolone and cyclosporin (CsA) the first year after transplantation may ha ve beneficial effects on glucose tolerance in renal transplant recipients. Methods. Ninety-one non-diabetic recipients were included, and 87 patients underwent a 75 g oral glucose tolerance test both 10 weeks and 1 year after renal transplantation. The change over time in 2-h blood glucose was compa red with a number of variables potentially influencing glucose tolerance. Results. The proportion of glucose intolerant recipients was reduced from 5 5 to 34% during the study. Univariate linear regression analysis showed a s ignificant association between the reduction in daily prednisolone dose dow n to 5 mg and decline in blood glucose (P = 0.001), whereas weight gain was associated with increasing blood glucose (P = 0.031). Each 1-mg reduction of prednisolone dose leads to an estimated decline in 2-h blood glucose of 0.12 mmol/l based on the multiple linear regression model (p = 0.003). Twel ve out of 22 patients with post-transplant diabetes mellitus (PTDM) at base line improved to normal or impaired glucose tolerance. Ten PTDM-subjects wh o remained diabetic 1 year after transplantation had lower serum insulin le vels during the oral glucose challenge, and five patients treated with anti -diabetic drugs at baseline required hypoglycaemic drugs also at follow up. The decline in CsA level of 100 mug/l and the lower number of patients tre ated with beta-blockers at follow-up, did not alter glucose tolerance signi ficantly. Conclusions. Tapering off prednisolone, but not CsA, significantly improves glucose tolerance during the first year after renal transplantation.