Contribution of Stone Size to Chronic Kidney Disease in Kidney Stone Formers Publisher Pubmed



Ahmadi F¹ ; Etemadi SM¹ ; Lessanpezeshki M¹ ; Mahdavimazdeh M¹ ; Ayati M² ; Mir A³ ; Yazdi HR⁴ Show Affiliations
Source: International Journal of Urology Published:2015

Abstract

Objectives: To determine whether stone burden correlates with the degree of chronic kidney disease in kidney stone formers. Methods: A total of 97 extracorporeal shockwave lithotripsy candidates aged 18years and older were included. Size, number and location of the kidney stones, along with cumulative stone size, defined as the sum of diameters of all stones) were determined. Estimated glomerular filtration rate was determined using the Chronic Kidney Disease Epidemiology Collaboration cystatinC/creatinine equation, and chronic kidney disease was defined as estimated glomerular filtration rate <60mL/min/1.73m2. Results: In individuals with cumulative stone size <20mm, estimated glomerular filtration rate significantly decreased when moving from the first (estimated glomerular filtration rate 75.5±17.8mL/min/1.73m2) to the fourth (estimated glomerular filtration rate 56.4±20.44mL/min/1.73m2) quartile (P=0.004). When patients with a cumulative stone size ≥20mm were included, the observed association was rendered non-significant. In individuals with a cumulative stone size <20mm, each 1-mm increase in cumulative stone size was associated with a 20% increased risk of having chronic kidney disease. The relationship persisted even after adjustment for age, sex, body mass index, C-reactive protein, fasting plasma glucose, thyroid stimulating hormone, presence of microalbuminuria, history of renal calculi, history of extracorporeal shockwave lithotripsy, number and location of the stones (odds ratio 1.24, 95% confidence interval 1.02-1.52). The same was not observed for individuals with a cumulative stone size ≥20mm. Conclusions: In kidney stone formers with a cumulative stone size up to 20mm, estimated glomerular filtration rate linearly declines with increasing cumulative stone size. Additionally, cumulative stone size is an independent predictor of chronic kidney disease in this group of patients. © 2014 The Japanese Urological Association.