Effect of Urolithiasis and Recurrent Urinary Tract Infection on Estimated GFR in CKD

Background: Urolithiasis is a known renal disease cause dependent on stone burden and number of interventions. Urinary tract infections (UTIs) are often associated with urolithiasis given the inflammatory state due to urinary flow obstruction. These two reversible risk factors can further cause progressive Chronic kidney disease (CKD). Methods: Objective: The primary study objective is to report the association of urolithiasis and urinary tract infection (UTI) with eGFR decline in CKD. Methods: A retrospective cohort study was conducted in a community nephrology clinic in Quebec, Canada that included laboratory and radiologic data collection from April 1, 2015 until June 30, 2022. Results: Upon review of 310 medical charts, the subjects had a median age of 73 years (IQR 29-99), and 58.1% of the cohort was male. The prevalence of Grade 1 and 2, Grade 3, Grade 4 and Grade 5 CKD was 10.3%, 50%, 32.3%, and 7.4%. The median follow-up time was 1555 days (28-4864). Urolithiasis was seen in 14.5%. The rate of UTIs was 0.107 events per patient-days. The multivariate generalized linear models (GLM) documented the proportionally reverse relationships between more than one UTI and decline in the individual slope of estimated GFR, reaching statistical significance. In the adjusted GLM, for every unit of ml/min/1.73m2/per day of decline in GFR slope, a 2% increase risk that is measured for recurrent UTI event (RR 1.02 (95%CI 1.00-1.04) p=0.0446. A tendency towards urolithiasis diagnosis was associated negatively with the slope of estimated GFR, as the RR for urolithiasis was 1.01 (95% CI 0.99-1.33), p=0.1136. There is an association of urolithiasis and average kidney size on GLM, p=0.0464. Recurrent UTI is associated with CKD grades with on trend analyses, p=0.049. The recurrent UTI proportions were 11%, 9% and 33% in CKD grade 3, 4 and 5, respectively among those with no urolithiasis. Majority of the UTIs were E. coli species (59%). Conclusion: Our study demonstrated an overall association between urolithiasis, recurrent UTIs and estimated GFR slope. Recurrent UTI is not associated with kidney size. Methods to prevent recurrent urolithiasis and urinary tract infection episodes should be assessed in a prospective manner. Funding: Commercial Support - Ortho Janssen