Influence of diabetes on survival in patients with cystic fibrosis before and after lung transplantation

Background: The influence of diabetes mellitus (DM) on survival in patients with cystic fibrosis (CF) before and after lung transplantation is not well studied. Methods: To determine the influence of DM in patients with CF, the United Network for Organ Sharing database (2005-2013) was queried for 2 cohorts: first-time lung transplant candidates who were not transplanted and first-time transplant recipients. Results: A total of 679 patients with CF had data on DM status at listing and did not undergo transplantation. In this cohort, DM was associated with significant increase in mortality hazard as shown by an adjusted multivariate Cox model fitted to the whole cohort (hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.1-1.8; P = .012) and by a Cox model stratified on pairs of DM and non-DM patients matched on the propensity of having DM at listing (HR, 1.9; 95% CI, 1.2-2.9; P = .003). In comparison, a total of 1464 patients with CF had data on DM status at listing and received a transplant, but DM at listing was not associated with post-transplant survival. The lack of association between DM and mortality hazard was evident in a multivariate Cox regression model fitted to the whole sample (HR, 1.0; 95% CI, 0.82-1.2; P = .98) and a Cox regression model stratified on matched pairs of DM and non-DM patients (HR, 1.1; 95% CI, 0.82-1.5; P = .56). Conclusions: The presence of DM is associated with significantly increased risk for death in patients with CF on the wait list before lung transplantation, but does not influence survival after transplantation.