Background

Diabetes increases morbidity and mortality following lung transplantation. Diabetes prevalence pre- and post-lung transplantation remains unknown. In cystic fibrosis (CF), we reported untreated prior diabetes impairs graft and patient survival. We determined the prevalence of diabetes in patients wait-listed for lung transplant and in transplanted recipients.

Methods

We performed analyses of all patients on the St Vincent’s Heart Lung database from 1/4/14 to 30/9/15 who were on the active waitlist (Study 1) and who had been transplanted (Study 2). Standard of care required all non-diabetic patients to undergo an oral glucose tolerance test (OGTT), modified for CF to screen for CF-related hyperglycaemia (CFRH:glucose ≥ 8.2 mmol/L at 60 or 90 minutes).

Results

In Study 1, we studied 114 patients who were waitlisted (32 with CF and 82 without). Twenty seven of 30 (90%) patients with CF with available glycaemic data had dysglycaemia: 18 had diabetes and 9 had CFRH. Of the 50 non-CF recipients with available glycaemic data, 8 (16%) had diabetes and 13 (26%) had pre-diabetes. In Study 2, amongst 25 CF patients who had undergone lung transplantation, 14 and 7 had pre-existing diabetes or CFRH respectively. All 7 patients with CFRH and 3 of 4 patients without diabetes or CFRH were diagnosed with diabetes post-transplantation. Hence, the prevalence of diabetes in CF patients post-transplantation was 96%. Among 53 non-CF patients who were transplanted, 7 were known to have had diabetes or pre-diabetes. Of those with pre-diabetes (n=4), without prior diabetes (n=21) or unknown diabetes status (n=25), 3, 11 and 16 respectively (60%) were diagnosed with diabetes post-transplantation.

Conclusion

There is a high prevalence of diabetes in lung transplant recipients, particularly in CF. These findings highlight the importance of early endocrine involvement in lung transplant services to improve graft and patient survival and reduce infection risk.