Sex Differences in Incidence and Outcomes of New‐Onset Post‐Transplant Diabetes Mellitus After Heart Transplantation

INTRODUCTION: Post-transplant diabetes mellitus (PTDM) is a common complication following heart transplantation (HT). The purpose of this study was to investigate sex differences in risk factors for the development of PTDM after HT, as well as in PTDM-related post-transplant outcomes, including acute cellular rejection (ACR), antibody-mediated rejection (AMR), cardiac allograft vasculopathy (CAV), and death. METHODS: A retrospective review of patients who underwent HT at a large-volume center between January 1, 2010 and December 31, 2019 was performed. PTDM was defined as hemoglobin A1C ≥ 6.5% or a random glucose >200 after HT among patients with no prior history of DM. Predictors of PTDM and post-HT outcomes were analyzed by sex. RESULTS: A total of 533 patients were transplanted during the study period and screened for inclusion. Among the 317 HT patients without pre-transplant DM, 71 (22.4%) developed PTDM: 24 women (33.7%), 47 men (66.2%). Baseline hypertension (OR 2.9, [1.3, 6.7], p = 0.009) and mean steroid dose over the first 2 years post-transplant (OR 1.2, [1.0, 1.3], p = 0.006) were predictors of PTDM in women but not in men, and mean tacrolimus dose was a predictor in men (OR 1.1, [1.0, 1.2], p = 0.001) but not in women while mean tacrolimus level was a predictor in women (OR 1.2, [1.0, 1.2], p = 0.034) but not in men. Post-transplant outcomes, including ACR, AMR, CAV, and death, did not differ between men with and without PTDM. However, women with PTDM had a higher rate of AMR (38% vs. 18%, p = 0.04) as compared to women without PTDM. There were no significant differences in rates of ACR, CAV, infection requiring hospitalization, or death among women. CONCLUSION: PTDM is a common complication of HT. Our study suggests that risk factors for PTDM and outcomes among HT patients differ by sex.