Correlation analysis between urinary crystals and upper urinary calculi

Abstract

Objective: This study aimed to analyze the correlation between urinary crystals and urinary calculi.

Methods: Clinical data, including urinary crystal types, were collected from 237 patients with urinary calculi. The detection rate of urine crystals and their correlation with stone composition were analyzed. The receiver operating characteristic curve analysis was used to determine the best cut-off value for predicting stone formation risk based on calcium oxalate crystals in urine.

Results: Calcium oxalate was the most common component in 237 patients. Among them, 201 (84.81%) patients had stones containing calcium oxalate. In these patients, calcium oxalate crystals were detected in 45.77% (92/201) of cases. In different groups of calcium oxalate stones, calcium oxalate crystals accounted for more than 90% of the total number of crystals detected in each group. The detection rate of calcium oxalate crystals was higher in first-time stone formers than in recurrent patients. The receiver operating characteristic curve analysis suggested a cut-off value of 110 crystals/μL for predicting stone formation, validated with 65 patients and 100 normal people.

Conclusion: Calcium oxalate crystals in urine can predict the composition of calcium oxalate stones and indicate a higher risk of stone formation when the number exceeds 110 crystals/μL. This non-invasive method may guide clinical treatment and prevention strategies.

Keywords: Calcium oxalate crystal; Calculus; Predict model; Urine crystal.