Association of Pre-Existing Type 2 Diabetes on Kidney Transplant Outcomes and Factors Correlating With Survival: A Single-Center Analysis

Introduction: Kidney transplantation (KT) is the treatment of choice for end-stage renal disease. Diabetes mellitus is the most common indication for KT, with most recipients having type 2 diabetes mellitus (T2DM). Previous studies have shown inferior patient survival in T2DM KT recipients. This single-center study aimed to understand the individual factors associated with negative long-term outcomes. Methods: This is a single-center retrospective analysis of adult KT recipients, with and without T2DM from 2012 to 2017 with a follow-up through December 2022. Primary Outcomes were graft loss and patient survival. Univariate, Multivariate Cox regression, and Kaplan–Meier analyses were used to assess KT outcomes. Results: We analyzed 1185 patients, 288 (24.3%) with T2DM. T2DM patients tended to be older, 56.6 ± 9.8 versus 47.1 ± 13.7 y. (P < 0.01), male (66.3% versus 58.2% P < 0.001) had a higher body mass index, 31.3 ± 5.4 versus 27.4 ± 5.7 P < 0.01) and less likely to get a living donor transplant (46.5% versus 58.4%, P < 0.01). T2DM patients after KT had a 50% higher risk for graft loss (hazard ratio 1.509, 95% CI 1.15-1.95, P < 0.001) and a 106% higher risk of death (hazard ratio 2.06 (95% CI 1.48-2.87, P < 0.0001). Among the T2DM patients, the most common cause of death was infection (39.9%). The average HbA1c at 1 y after transplant was 7.8%. Conclusions: The present study shows that T2DM is strongly associated with an increased risk of graft loss and death after KT, particularly in older recipients of deceased donor transplants with longer cold ischemia time that experience delayed graft function. This underscores the importance of avoiding delayed graft function in older, type 2 diabetic kidney transplant recipients and prioritizing living donors.