Background: To investigate the clinical factors associated with susceptibility to infection stone formation and to analyze the variations in the clinical characteristics of stones with different compositions.
Methods: A total of 1213 patients were included in the study. The patients were grouped based on stone composition; 581 cases of infection stones (ammonium magnesium phosphate calculi or apatite carbonate content more than 50%), 418 stones were composed of pure calcium oxalate, and 214 uric acid stone. The associations of infection stones with age, sex, body mass index, habits, working environment, recurrent stones, diabetes, hypertension, urinary tract infection, urine culture, urine pH, and triglycerides were determined using logistic regression analysis. The variations in the clinical characteristics of the 3 groups were analyzed using analysis of variance or the chi-square test.
Results: The occurrence of infection stones was significantly associated with the patient’s age (odds ratio [OR]: 1.031, 95% confidence interval [CI]: 1.020–1.041, P<0.001), high urine pH (OR: 1.974, 95% CI: 1.357–2.872, P<0.001), urinary tract infection (OR: 1.438, 95% CI: 1.072–1.928, P=0.015), positive urine cultures (OR: 1.541, 95%CI: 1.143–2.078, P=0.005), and recurrent stones (OR: 1.346, 95% CI: 1.045–1.734, P=0.022), other clinical factors have no correlation. The clinical characteristics of the three groups were significantly different. The occurrence of infection stones is significantly associated with age, urinary tract infection, positive urine cultures, urine pH, and stone recurrence.
Conclusions: Compared with previous studies, this study found that infection stones tend to occur in younger patients and stones resulting from non-urease-producing bacteria have significantly increased.