Associations of height-for-age and BMI-for-age Z-scores with pediatric urolithiasis: a multicenter study

Background Pediatric urolithiasis is an increasing public health concern in high-prevalence regions, but the relationship between child growth status and the odds of stone disease remains unclear. Objective This study aimed to evaluate the associations of height-for-age Z -score (HAZ) and BMI-for-age Z -score (BAZ) with pediatric urolithiasis in a large multicenter population from Xinjiang, China. Methods This hospital-based retrospective multicenter case–control study included 14,027 children aged <15 years, comprising 2,180 children with imaging-confirmed renal and/or ureteral stones and 11,847 controls without urolithiasis. HAZ and BAZ were calculated according to World Health Organization growth standards and references. Multivariable logistic regression models were used to assess associations between HAZ, BAZ, and urolithiasis after adjustment for sex, ethnicity, age, and study center. Restricted cubic spline models were used to examine dose–response and nonlinear relationships, and subgroup analyses were performed by study center, sex, ethnicity, age group, and nutritional status. Results Children with urolithiasis had lower HAZ and BAZ than controls (HAZ: −0.79 (−1.74, 0.24) compared with 0.57 (−0.29, 1.41); BAZ: −0.25 (−1.19, 0.77) compared with 0.36 (−0.61, 1.43); both p < 0.001). After full adjustment, each 1-unit increase in HAZ was associated with 36% lower odds of urolithiasis (odds ratio: 0.64; 95% CI: 0.61, 0.66; p < 0.001), and each 1-unit increase in BAZ was associated with 21% lower odds (odds ratio: 0.79; 95% CI: 0.76, 0.81; p < 0.001). HAZ showed a nonlinear inverse association with the estimated odds of urolithiasis, whereas BAZ showed an approximately linear inverse association. Subgroup analyses showed that the inverse associations were generally consistent across sexes and ethnicities. For HAZ, significant interactions were observed by study center, age group, and BAZ-defined nutritional status, whereas BAZ showed more stable associations across most subgroups. Conclusion Lower HAZ and BAZ were associated with higher odds of pediatric urolithiasis, with HAZ showing a stronger and nonlinear association.