Kidney stone formers with a cumulative stone size less than 20 mm are at increased risk for chronic kidney disease (CKD), Iranian investigators reported online ahead of print in the International Journal of Urology.
Farrokhlagha Ahmadi, MD, of the Tehran University of Medical Sciences, and colleagues studied 97 stone formers who were candidates for extracorporeal shockwave lithotripsy.
Among patients with a cumulative stone size (the sum of diameters of all stones) less than 20 mm, the estimated glomerular filtration rate (eGFR) decreased significantly from the first measurement (75.5 mL/min/1.73 m2) to the fourth (56.4 mL/min/1.73 m2).
Each 1 mm increment in cumulative stone size was associated with a 20% increased risk of CKD, which the researchers defined as an eGFR below 60 mL/min/1.73 m2. The investigators observed no association between cumulative stone size and CKD among patients with a cumulative stone size 20 mm or greater.