Diabetes mellitus (DM) is common following lung transplant (LTx) and is an independent risk factor for mortality. No studies to date have prospectively determined the incidence or prevalence of DM using the oral glucose tolerance test (OGTT) pre and post LTx. Further, changes in metabolic parameters following LTx and risk factors for persistent DM following LTx have not been comprehensively studied.
Methods
Prospective, longitudinal study comparing DM status before and after LTx, using the OGTT. DM prevalence and changes in metabolic control over time were determined. Risk factors for persistent new onset DM after transplant (NODAT) and survival differences by DM status were assessed.
Results
Between 1/8/2010 – 1/12/2012, 156 patients underwent LTx. Baseline DM prevalence was 25%, increasing to 47%, 44% and 40% at 3, 12 and 24 months respectively. Impaired glucose tolerance &/or impaired fasting glucose was present in a further 15% at baseline and 20%, 11% and 7% at 3, 12 and 24 m. Incidence of NODAT was 31%, 29% and 17% at 3, 12 and 24 m.
Non-fasting insulin levels fell 3 months after Tx but returned to baseline by 2 years.
PreTx DM was the strongest predictor of persistent DM post Tx. The only risk factors for NODAT were 1 and 2 h glucose levels on preTx OGTT (OR 1.73 (95% CI 1.19–2.50), p=0.004 and 1.84 (1.22–2.77), p=0.004 respectively).
Survival was reduced in patients with DM at study end vs those without (estimated mean 979 (888-1071) vs 1140 (1070–1210) d, p=0.023).
Conclusion
Most patients had dysglycemia during the first year after LTx and 32% developed NODAT. Only preTx OGTT glucose levels predicted persistent NODAT. As DM was common and associated with reduced survival, early detection and management of DM in LTx recipients is warranted.