Potassium-sodium citrate prevents the development of renal microcalculi into symptomatic stones in calcium stone-forming patients

Abstract

Objectives: To evaluate the effect of potassium-sodium citrate on the development of computed tomography-detected renal microcalculi into symptomatic stones in calcium stone-forming patients. Methods: Patients (aged 20–80 years) with history of calcium component stones who visited Nagoya City Hospital, Nagoya, Aichi, Japan, between April 2009 and June 2014 were included. They were retrospectively divided into those who did not receive potassium-sodium citrate (non-citrate group, n = 157) and those who did (citrate group, n = 60). For patients in both groups, we evaluated blood and urine biochemistry and sediment, number of computed tomography-detected microcalculi, number of asymptomatic microcalculi disappearances, and pain events. Observations were made at study initiation and 12 months later. Results: The citrate group showed a significantly increased urine pH (P < 0.001) and daily citrate excretion (P < 0.001) over the study period. The non-citrate group showed increased numbers of microcalculi at study completion (P = 0.002); over the same period, the number of microcalculi in the citrate group decreased significantly (P = 0.03). Additionally, multivariable analysis showed more asymptomatic microcalculi disappearances (odds ratio 2.84, 95% confidence interval 1.49–5.39) and fewer pain events (odds ratio 0.37, 95% confidence interval 0.16–0.72) in the citrate group than in the non-citrate group. A sex-adjusted analysis showed more asymptomatic microcalculi disappearances (odds ratio 3.96, 95% confidence interval 1.57–10.02) and fewer pain events (odds ratio 0.22, 95% confidence interval 0.07–0.70) in women than in men after citrate treatment. Conclusions: Potassium-sodium citrate prevents the development of renal microcalculi into symptomatic stones in calcium stone-forming individuals.