Introduction: Urinary tracts infections (UTIs) are a common complication after kidney transplantation. Immunosuppression, urological factors and traditional risk factors affect the occurrence of UTIs. The aim of this study was to investigate the impact of diabetes mellitus, whether pre-existing or newly occurring after transplantation, on the occurrence and severity of UTIs in kidney transplant recipients.
Method: We performed a retrospective analysis including 299 adult patients transplanted with a kidney between 2018 and 2022. Patients were categorized into pre-transplantation diabetics, post-transplantation diabetics, and non-diabetics. Urinary tract infections were defined according to the American Society of Transplantation definitions. Asymptomatic bacteriuria and lower urinary infections were not included.
Results: The median follow-up time was 29 months. We observed a higher occurrence of UTIs in pre-transplant diabetics (41.2%) and post-transplant diabetics (39.3%) compared to non-diabetics (28.2%, p<0.05). The median time from transplantation to UTIs was 3 months for pre-transplant diabetics and 6 months for non-diabetics and post-transplant diabetics. Pre-transplant diabetes emerged as a significant risk factor for UTIs (adjusted Hazard Ratio (HR): 1.7, 95% CI: 1.1 - 2.7), with gender, urinary catheterization, and obesity as additional risk factors. UTIs did not affect patient survival in diabetics and non-diabetics patients.
Conclusion: Pre- and post-transplant diabetes mellitus increase the risk of UTIs occurrence in kidney transplant recipients. Pre-transplant diabetes arises as a significant risk factor for UTIs after kidney transplantation.