Pretransplantation C-Peptide level predicts early posttransplantation diabetes mellitus and has an impact on survival after allogeneic stem cell transplantation.

Posttransplantation diabetes mellitus (PTDM) is a frequent complication after allogeneic stem cell transplantation (allo-SCT), important for its negative impact on cardiovascular health. Risk factors for PTDM are not well defined. We conducted a prospective study to investigate the risk factors and incidence for PTDM in the first 100 days after allo-SCT. A total of 84 patients completed the study, 60% of whom developed PTDM. In a multivariate logistic regression model, pretransplantation c-peptide level (>3.6 ng/mL; odds ratio [OR], 5.9; 95% confidence interval [CI], 1.77-20.22; P = .004), unrelated donor allo-SCT (OR, 4.3; 95% CI, 1.34-14.2; P = .014), and peak steroid dose >1 mg/kg/day (OR, 5.09; 95% CI, 1.19-23.2; P = .035) were identified as independent predictors of PTDM. In addition, overall survival (OS) was inferior in patients with PTDM compared with those without PTDM (mean survival, 2.26 years vs 2.7 years; P = .021). Pretransplantation c-peptide level greater than the cohort median (>3.6 ng/mL) also was associated with inferior OS (mean, 1.7 years vs 2.9 years; P = .012). In a multivariate Cox proportional hazards model, high-risk disease (hazard ratio [HR], 2.34; 95% CI, 1.09-5.28; P = .029) and pretransplantation c-peptide level >3.6 ng/mL (HR, 1.05; 95% CI, 1.01-1.09; P = .013) were independent predictors of OS when adjusted for systemic steroids and regimen intensity. We suspect that diabetes mellitus in the immediate posttransplantation period may be mediated via an inflammatory pathway that contributes to insulin resistance in the host adipose tissue. Our study is the first to report the risk factors of early PTDM in patients undergoing allo-SCT and identifies pretransplantation c-peptide as an independent predictor of diabetes and survival.