Cardiovascular morbidity and mortality in patients with diabetes mellitus type I after kidney transplantation: a case-control study

Abstract

Background: The proportion of diabetics among patients requiring renal replacement therapy continues to increase in most western countries. The acceptance rate for renal transplantation varies among transplant centers and is influenced by the current opinion on the outcome of transplantation in diabetics. Controlled data on patient and graft survival in type I diabetics, however, are scarce.

Methods: We performed a retrospective case-control analysis on patient and graft survival and the cardiovascular morbidity of patients with type I diabetes after renal transplantation versus carefully matched non-diabetic transplant recipients. Match criteria were duration of previous hemodialysis, age and date of renal transplantation. Moreover, risk factors for cardiovascular disease in uremic patients were evaluated at the time of registration for renal transplantation and at the end of the observation period.

Results: Seventy-seven matched pairs were enclosed. Patient survival was significantly worse in the diabetic patients, graft survival was comparable in both groups, when graft loss because of patient's death was censored. In the diabetic patients, risk of death (odds ratio: 4.38) as well as the prevalence of cardiovascular morbidity (odds ratio: 4.47) were significantly higher than in the matched nondiabetic controls. Cox regression analysis showed that diabetes mellitus was an independent risk factor for patient survival; no association was found with hypertension, hyperlipidemia, hyperparathyroidism, calcium x phosphate product, body mass index and HbA1c. Cardiovascular morbidity, however, was already significantly higher in the diabetic group at the time of registration.

Conclusions: Diabetes mellitus type I has a dominant impact on morbidity and mortality after renal transplantation and is associated with an approximately 4-fold higher risk of death. Cardiovascular disease accounts for the significantly worse long-term outcome of diabetic patients after renal transplantation.