Post-transplant diabetes mellitus after kidney transplantation: longitudinal treatment trajectories and exploratory clinical outcomes

Post-transplant diabetes mellitus (PTDM) is a common complication after kidney transplantation, but its longitudinal course after diagnosis may be heterogeneous. We conducted a single-centre retrospective cohort study of kidney transplant recipients diagnosed with PTDM between January 2010 and December 2020 to describe longitudinal glucose-lowering treatment trajectories and exploratory clinical outcomes. Patients with known diabetes before transplantation were excluded. PTDM was defined according to the international consensus framework as abnormalities in glucose metabolism persisting beyond 45 days after discharge. Eighty-three recipients were followed for a median of 76 months (IQR 60–107). At last follow-up, 72 patients (86.7%) remained on glucose-lowering therapy, whereas 11 (13.3%) had discontinued treatment without documented recurrence of hyperglycaemia. In exploratory comparisons, the persistent-treatment group showed a steeper annual decline in allograft function (− 2.30 vs −0.30 mL/min/1.73 m 2 /year; p = 0.004) and more frequent new-onset proteinuria (57.4% vs 18.2%; p = 0.022). All deaths and graft-loss events occurred in the persistent-treatment group; however, these event-based comparisons are limited by the small discontinuation subgroup and by the post hoc, time-dependent nature of treatment classification. These findings are descriptive and hypothesis-generating. Treatment discontinuation cannot establish that the initial abnormality represented transient hyperglycaemia, and treatment persistence cannot be interpreted as an independent determinant of graft outcomes.