A Comparative Study on Graft and Overall Survival Rates Between Diabetic and Nondiabetic Kidney Transplant Patients Through Survival Analysis

Abstract

Background: Patients with diabetes mellitus (DM) have worse graft and overall survival, but recent evidence suggests that the difference is no longer significant. Objective: To compare the outcomes between patients with end-stage kidney disease due to DM (ESKD-DM) and ESKD due to nondiabetic etiology (ESKD-non-DM) who underwent kidney transplantation (KT) up to 10 years of follow-up. Design: Survival analysis of a retrospective cohort. Setting and Patients: All patients who underwent KT at the Hospital Universitario San Ignacio, Colombia, between 2004 and 2022. Measurements: Overall and graft survival in ESKD-DM and ESKD-non-DM who received KT. Patients who died with functional graft were censored for the calculation of kidney graft survival. Methods: Log-rank test, Cox proportional hazards model, and competing risk analysis were used to compare overall and graft survival in patients with ESKD-DM and ESKD-non-DM who underwent KT. Results: A total of 375 patients were included: 60 (16%) with ESKD-DM and 315 (84%) with ESKD-non-DM. Median follow-up was 83.3 months. Overall survival was lower in patients with ESKD-DM at 5 (75.0% vs 90.8%, P < .001) and 10 years (55.0% vs 86.7%, P < .001). Cardiovascular death was higher in patients with diabetes (27.3% vs 8.2%, P = .021). Death-censored graft survival was similar in both groups (96.7% vs 93.3% at 5 years, P = .324). On multivariate analysis, the factors associated with global survival were DM (hazard ratio [HR] = 2.11, 95% confidence interval [CI] = 1.23-3.60, P = .006), recipient age (HR = 1.05, 95% CI = 1.02-1.08, P < .001), delayed graft function (HR = 2.07, 95% CI = 1.24-3.46, P = .005), and donor age (HR = 1.03, 95% CI = 1.01-1.05, P = .002). In the competing risk analysis, DM was associated with mortality only in the cardiovascular death group (sub-hazard ratio [SHR] = 6.06, 95% CI = 1.01-36.4, P = .049). Limitations: Change in diabetes treatment received over time and adherence to glycemic targets were not considered. The sample size is relatively small, which limits the precision of our estimates. The Kidney Donor Profile Index and the occurrence of treated acute rejection were not included in the regression models. Conclusion: Overall survival is lower in patients with diabetes, possibly due to older age and cardiovascular comorbidities. Therefore, patients with diabetes should be followed more closely to control cardiovascular risk factors. However, there is no difference in graft survival.