The Impact of Infections on the Progression of Chronic Kidney Disease

Background and Objective: Infectious diseases continue to be a global burden and their impact is even worse if the patients already have other comorbidities. Because chronic kidney disease is very frequent, affecting 10% of the population, our study aims to explore the impact that infectious events have on its progression. Material and Methods: This is a retrospective, observational study based on a cohort of 238 dialyzed patients from the Nephrology Clinic of "Dr. Carol Davila" Clinical Hospital of Nephrology, Bucharest, who were followed from their first visit for five years, between 1 January 2007 and 1 January 2022. For each of them, the presence of an infectious event and the moment of the initiation of dialysis were recorded. Results: Statistical analysis showed that the patients who had at least one infectious episode were older (p = 0.004), their hemoglobin and lymphocytes were significantly lower (p = 0.03 and p = 0.02, respectively) and the time until the initiation of dialysis was lower (p = 0.007). Also, the preservation of kidney function was influenced by the number and the severity of infectious episodes. In the univariate Cox model, the following variables were associated with increased risk of dialysis: advanced age (p: 0.009; HR: 1.021; CI: 1.005 to 1.036), low hemoglobin (p: 0.001; HR: 0.861; CI: 0.786 to 0.943), previous diagnosis of chronic obstructive pulmonary disease (p: 0.002; HR: 2.467; CI: 1.376 to 4.424), presence of hematuria (p: 0.03; HR: 1.604; CI: 1.047 to 2.457) and increased values of proteinuria (p: 0.01; HR: 1.122; CI: 1.028 to 1.224) and of serum creatinine measured both at the time of the first visit and at the time of each infectious event (p: <0.001; HR: 1.262; CI: 1.141 to 1.396). Also, the presence of an infectious episode was associated with a 1.7-fold increase in the risk of dialysis initiation. The independent predictors of survival identified by the multivariate Cox model were age (p: 0.004; HR: 1.034; CI: 1.010-1.058), serum creatinine (p: <0.001; HR: 1.421; CI: 1.203 to 1.658) and proteinuria (p: <0.001; HR: 1.241; CI: 1.126 to 1.369) at the time of enrollment, but also the presence of an infectious episode during the patient's evolution (p: 0.04; HR: 1.705; CI: 1.013 to 2.868). Conclusions: In the evolution of patients with chronic kidney disease, an active search for individual factors favoring the occurrence of infectious episodes should be taken into consideration to prevent a faster progression toward end-stage kidney disease.