High-risk factors for urinary calculus recurrence in Chinese preschool children: findings from a medium-term follow-up survey.

Background: To date, most literature has focused on factors contributing to the initial occurrence of pediatric urinary stones. However, there is scant literature on the risk factors for recurrence following the initial episode. Effective treatment strategies for the initial episode and measures to reduce the risk of stone recurrence are crucial. This study aimed to investigate the impact of children's dietary habits on the recurrence of urinary stones in children. Methods: A retrospective analysis was conducted on the clinical data of pediatric patients diagnosed with urinary stones by the Department of Urology at Beijing Friendship Hospital Affiliated with Capital Medical University from January 2014 to December 2023. Dietary habits were compared between patients who experienced recurrence and those who did not. Results: We conducted a follow-up study from January 2014 to December 2023 on 310 children with urinary stones. During the follow-up period, which had a median duration of 50.93±1.79 months, 62 patients (20.0%) experienced recurrence, while 248 patients (80.0%) did not. Among the recurrent patients, 9 (14.5%) did not consume animal proteins, 21 (33.9%) had low water intake, and 34 (54.8%) had a high dietary oxalate intake. In comparison, among the non-recurrent patients, 34 (13.7%) did not consume animal proteins, 36 (14.5%) had low water intake, and 120 (48.4%) had a high dietary oxalate intake. Univariate analysis revealed that a high-protein diet [odds ratio (OR) =0.805, 95% confidence interval (CI): 0.707-0.917, P<0.001] was a protective factor against recurrence, while a high oxalate diet (OR =1.335, 95% CI: 1.146-1.554, P<0.001), low water intake (OR =1.138, 95% CI: 1.013-1.279, P=0.03), and younger age at onset (OR =1.062, 95% CI: 1.025-1.110, P=0.001) were identified as risk factors. In multivariate analysis, the high-protein diet remained a protective factor (OR =0.825, 95% CI: 0.725-0.940, P=0.004), while high dietary oxalate intake (OR =1.304, 95% CI: 1.122-1.515, P<0.001), low water intake (OR =1.141, 95% CI: 1.019-1.276, P=0.02), and younger age at onset (OR =1.076, 95% CI: 1.038-1.114, P<0.001) continued to be significant risk factors. Conclusions: The study concluded that a high-protein diet serves as a protective factor, whereas a high oxalate diet, low water intake, and younger age at onset are significant risk factors for the recurrence of pediatric urinary stones. The cumulative five-year recurrence rate of pediatric urinary stones was 18.1%. Therefore, dietary modifications, including increased protein intake and reduced oxalate consumption, along with ensuring adequate hydration, are crucial in managing pediatric urinary stones and preventing early recurrence.