Long-term survival following simultaneous kidney-pancreas transplantation versus kidney transplantation alone in patients with type 1 diabetes mellitus and renal failure

Background: Pancreas transplantation improves quality of life and prevents the progression of secondary complications of diabetes. Whether these benefits translate into a long-term survival advantage is not entirely clear. Methods: Using the United Network for Organ Sharing database, we analyzed long-term survival in 18,549 patients with type 1 diabetes and renal failure who received a kidney transplant between 1987 and 1996. Patient survival was calculated using the Kaplan-Meier method. Proportional hazards models were used to adjust for effects of differences in recipient and donor variables between simultaneous kidney-pancreas transplants (SKPTs) and kidney-alone transplants. Results: SKPT and living donor kidney recipients had a significant crude survival distribution advantage over cadaver kidney transplant recipients (8-year survival rates: 72% for SKPT recipients, 72% for living donor kidney recipients, and 55% for cadaver kidney recipients). The survival advantage for SKPT recipients over cadaver kidney recipients diminished, but persisted after adjusting for donor and recipient variables and kidney graft function as time-varying covariates. SKPT recipients had a high mortality risk relative to living donor kidney recipients through 18 months posttransplantation (hazards ratio, 2.2; P < 0.001), but had a lower relative risk (hazard ratio, 0.86; P < 0.02) thereafter. In SKPT recipients, maintenance of a functioning pancreas graft was associated with a survival benefit. Conclusion: The long-term survival of SKPT recipients is superior to that of cadaver kidney transplant recipients with type 1 diabetes. There is no difference in survival of SKPT recipients and living donor kidney recipients with type 1 diabetes at up to 8 years' follow-up; the former have a greater early mortality risk and the latter have a greater late mortality risk. Results of this study suggest that successful simultaneous kidney-pancreas transplantation is not only life enhancing, but life saving.