Retrospective analysis on incidence and risk factors of post-transplant diabetes mellitus after lung transplantation and its association with clinical outcomes.

Background: Post-transplant diabetes mellitus (PTDM) is a common complication after transplantation. We aim to explore potential risk factors of PTDM and its association with outcomes after lung transplantation (LTx).

Methods: A retrospective study was conducted in 100 patients who underwent LTx at our institution from 2017 to 2021. Patients' information was collected, and genotyping for single nucleotide polymorphisms known to potentially increase the risk of Type 2 DM was performed. Univariate and multivariate analyses were conducted to identify risk factors for PTDM. The primary outcome was the incidence of PTDM. Secondary outcomes were associations between PTDM and clinical outcomes following LTx.

Results: Thirty-nine patients (39.0%) developed PTDM, while 10 patients (25.6%) recovered subsequently. The incidence of PTDM was associated with age > 45 (HR: 2.919, 95% CI [1.021-8.348]), pre-transplant HbA1c > 5.7% (HR: 2.344, 95% CI [1.201-4.573]), KCNJ11 rs5215 (HR: 2.090, 95% CI [1.050-4.162]) and tacrolimus concentration > 8 ng/mL in the first month (HR: 2.090, 95% CI [1.050-4.162]). Patients with PTDM experienced elevated fasting blood glucose levels (FBG) during the first month post-transplantation (p < 0.001), and required a longer duration for FBG to return to normal levels (p < 0.001). However, the presence of PTDM did not significantly impact renal function, incidence of infection episodes, chronic lung allograft dysfunction or mortality following LTx.

Conclusion: Advanced age, elevated HbA1c levels, KCNJ11 gene polymorphism, and early exposure to tacrolimus are all significant risk factors for PTDM following LTx. The clinical implications of these factors warrant attention.