Pre-existing diabetes significantly increases the risk of graft failure and mortality following renal transplantation.

The aim of this study was to examine the impact of pre-existing diabetes mellitus (DM) on acute rejection, graft loss, and mortality following kidney transplant and whether glycemic control or cardiovascular disease (CVD) risk control with medications influenced outcomes. This was a cohort study of 1002 renal transplants conducted between 2000 and 2008. Patients were included if they received a kidney transplant within the allotted time and were at least 18 yr of age. Cox regression was used to assess acute rejection, graft failure, or death controlling for relevant sociodemographic, clinical, and post-transplant variables. Five-yr patient survival (83% vs. 93%, p < 0.001) and graft survival (74% vs. 79%, p = 0.005) were significantly lower in patients with pre-existing DM. Sequential Cox regression models demonstrated that pre-existing DM was consistently associated with a higher risk of death (HR 2.3-3.0, p < 0.01) and graft failure (HR 1.5-1.8, p < 0.04) in all models except after adjusting for CVD medication use (HR 1.9, p = 0.174 and HR 1.5, p = 0.210, respectively). These data suggest pre-existing DM is a significant risk factor for graft failure and death following renal transplantation and aggressive CVD risk reduction with medications may be an important strategy to reduce mortality and graft failure.