Effect of simultaneous pancreas-kidney transplantation on mortality of patients with type-1 diabetes mellitus and end-stage renal failure

Background Long-term prognosis of patients with type-1 diabetes mellitus and end-stage renal failure appears to be better after kidney transplantation compared with dialysis. Controversy exists about the additional benefit of a simultaneously transplanted pancreatic graft. We studied the effect on mortality of simultaneous pancreas-kidney transplantation compared with kidney transplantation alone from regional differences in transplantation protocols. Methods All 415 patients with type-1 diabetes (aged 18–52 years) who started renal-replacement therapy in the Netherlands between 1985 and 1996 were included in the analysis. Patients were allocated to a centre based on their place of residence at onset of renal failure. In the Leiden area, the primary intention to treat was with a simultaneous pancreas-kidney transplantation, whereas in the non-Leiden area, kidney transplantation alone was the predominant type of treatment. All patients were followed up to July, 1997. Analyses, mortality, and graft failure were by Cox proportionalhazard model adjusted for age and sex. Findings Simultaneous pancreas-kidney transplantation was done in 41 (73%) of 56 transplanted patients in the Leiden area compared with 59 (37%) of 158 transplanted patients in the non-Leiden area (p<0·001). The hazard ratio for mortality after the start of renal-replacement therapy was 0·53 (95% CI, 0·36–0·77, p<0·001) in the Leiden area compared with the non-Leiden area. When just the transplanted patients were analysed the mortality ratio was 0·4 (95% CI 0·20–0·77, p=0·008) and was independent of duration of dialysis and early transplant-related deaths. Equal survival was found for patients on dialysis only. Interpretation These data support the hypothesis that simultaneous pancreas-kidney transplantation prolongs survival in patients with diabetes and end-stage renal failure.