Impact of Early Post-Transplantation Diabetes Mellitus and Changes in Diabetic Status on Graft Failure and Mortality in Kidney Transplant Recipients

Post-transplantation diabetes mellitus (PTDM) is a common complication following kidney transplantation (KT), but the prognostic significance of early PTDM and changes in diabetic status remains uncertain. Using the Korean National Health Insurance Service (NHIS) database, we analyzed 8,486 KT recipients (KTRs) who underwent national health screening from 2009 to 2017. Early PTDM was defined as new-onset diabetes between 3 months and 1 year after KT. Cox regression was used to estimate the risk of graft failure and all-cause mortality. Early PTDM and preexisting DM were present in 12.2% and 28.5% of KTRs, respectively. Early PTDM was significantly associated with mortality (aHR 1.309, 95% CI 1.015–1.689) but not with graft failure. Changes in diabetic status were not significantly associated with graft failure. However, transitioning from non-DM to PTDM (aHR 1.646, 95% CI 1.080–2.510) and having persistent early PTDM (aHR 1.755, 95% CI 1.325–2.377) were associated with increased mortality, whereas regression from early PTDM to non-DM was not. Preexisting DM was associated with increased mortality, regardless of subsequent changes; the risk was relatively lower in those who regressed to non-DM. Changes in diabetic status were found to have a greater impact on outcomes than early PTDM, highlighting the importance of continuous glycemic monitoring and individualized care in KTRs.