Infection-related mortality is higher for kidney allograft recipients with pretransplant diabetes mellitus

The risk of infection-related mortality in kidney allograft recipients with pre-existing diabetes mellitus is unknown. We determined the risk of infection-related mortality after kidney transplantation in a population-based cohort stratified by diagnosis of pre-existing diabetes mellitus. We linked data between two national registries (Hospital Episode Statistics and the Office for National Statistics) to select all mortality events after kidney transplantation in England between April 2001 and March 2012. The primary outcome measure was infection-related mortality after transplantation comparing diabetic with non-diabetic recipients. A total of 19,103 kidney allograft recipients were analysed; 2,968 (15.5%) were known to have diabetes before kidney transplantation. After transplantation, 2,085 deaths (10.9%) occurred (median follow-up 4.4 years [interquartile range 2.2-7.3]), with 434 classified as secondary to infection (20.8% of all deaths). Risk of overall (16.0% vs 10.0%, p < 0.001) and infection-related (3.3% vs 2.1%, p < 0.001) mortality after kidney transplantation was higher for diabetic than non-diabetic recipients, respectively. No cytomegalovirus-related deaths occurred in diabetic recipients compared with 5.7% in non-diabetic recipients (p < 0.007), with a trend towards more unspecified sepsis in diabetic recipients (30.6% vs 22.6%, respectively, p = 0.070). Diabetes at the time of transplantation was an independent risk factor predicting infection-related mortality in kidney allograft recipients after transplantation (HR 1.71 [95% CI 1.36, 2.15], p < 0.001). Infection-related mortality is more common in kidney allograft recipients with pre-existing diabetes mellitus. Further work is required to determine whether attenuated immunosuppression is beneficial for diabetic kidney allograft recipients.