The change of stones composition and its related risk factors in recurrent urolithiasis / 中国医师进修杂志

ABSTRACT

Objective To investigate the proportion, risk factors and tendency of the change of stones composition in recurrent urolithiasis. Methods One hundred and fifty-six recurrent urolithiasis patients from January 2011 to January 2016 were enrolled. Compositions of initial and recurrent stones were measured by infrared spectrophotometry. Stones types, recurrence interval and recurrence frequency were studied as potential risk factors for composition change. Chi square test and Logistic regression analysis was employed in the statistical analysis. Results Stones composition changed during recurrence in 48 patients (30.8%). 22.8%(18/79) of calcium oxalate stones change to infection stones, and 25.8%(8/31) of infection stones changed to calcium oxalate. Univariate analysis showed the risk ratio of composition change in the patients with recurrence interval of 1- 5 years was 0.529(P = 0.039) , compared with those of less than 1 year or more than 5 years. Logistic regression analysis showed the odds ratio of recurrence interval of 1- 5 years was 0.242 (95%CI 0.086- 0.718, P = 0.012). Conclusions Stones composition changes in about 30.8% of recurrent urolithiasis. The mutual conversion between calcium oxalate and infection stones is the most common. Recurrence interval is an independent risk factor to predict composition change.