A case-control study on the risk factors of urinary calculus in Uyghur children in the Kashi region

Prevalence of urolithiasis among the Uyghur children of China: a population-based cross-sectional study

OBJECTIVES

To investigate the prevalence and associated factors of urolithiasis amongst Uyghur children.

SUBJECTS AND METHODS

A cross-sectional survey was conducted of Uyghur children (aged ≤14 years) in the Kashgar Region of China, from July to December 2016. Children were selected by a two-stage random clustered sampling method, evaluated by urinary tract ultrasonography, low-dose computed tomography (CT) examination, blood and urine analysis, and a questionnaire. The prevalence by CT, the prevalence by self-report in the questionnaires, and the lifetime prevalence were evaluated. Binary logistic regression was used to estimate the associated factors.

RESULTS

A total of 5605 children were selected and invited to participate in the study. In all, 4813 Uyghur children (2471 boys and 2342 girls), with an mean (SD; range) age of 75.79 (43.81; 2-177) months, were included in the final analysis, with a response rate of 85.9%. The prevalence of paediatric urolithiasis was 1.8% (95% confidence interval [CI] 1.5-2.2) by CT, 2.3% (95% CI 1.9-2.7) by self-report, and 3.6% (95% CI 3.0-4.1) for the overall life-time. The age-sex adjusted prevalence was 2.0% (95% CI 1.6-2.4) by CT. Binary logistic regression analysis showed that body mass index, urinary tract infection, a family history of urolithiasis, and excessive sweating could increase the risk of stone formation, whilst breast feeding and drinking water at midnight could decrease the risk.

CONCLUSIONS

Urolithiasis is a major public health problem amongst Uyghur children, and strategies aimed at the prevention of urolithiasis are needed.

Biochemical metabolic levels and vitamin D receptor FokⅠ gene polymorphisms in Uyghur children with urolithiasis

Because of lacking studies of urolithiasis in children, we detected the biochemical metabolic levels and FokⅠ polymorphisms in the vitamin D receptor (VDR) in Uyghur children with urolithiasis, and evaluated the associations of biochemical metabolic levels with FokⅠ genotypes. We included 142 Uyghur children (108 males) under age 14 years with a diagnosis of urolithiasis and 238 Uyghur children (154 males) under age 14 years without a history of urolithiasis as controls. Baseline information and data for serum and urine parameters were obtained from medical records. PCR-restriction fragment length polymorphism (PCR-RFLP) was used to analyze the VDR FokⅠ polymorphisms. In univariate analyses adjusting for age and sex, carbon dioxide combining power (CO2CP) (odds ratio [OR] = 1.13, 95% confidence interval [CI]: 1.07-1.19), serum magnesium (Mg) (OR = 1.27, 95% CI: 1.03-1.56) and serum chlorine (Cl) (OR = 0.93, 95% CI: 0.88-0.97) were related to Uyghur children urolithiasis risk. A multiple logistic regression model showed CO2CP (OR = 1.17, 95% CI: 1.09-1.26), levels of uric acid (OR = 1.01, 95% CI: 1.00-1.01) and serum sodium (Na) (OR = 0.90, 95% CI: 0.82-0.99) were associated with pediatric urolithiasis. The risk of urolithiasis was increased with the F versus f allele overall (OR = 1.42; 95% CI: 1.01-2.00) and for males (OR = 1.52, 95% CI: 1.02-2.27). However, metabolic levels did not differ by FokⅠ genotypes. In our population, CO2CP and levels of uric acid and serum Na as well as polymorphism of the F allele of the VDR FokⅠ may provide important clues to evaluate the risk of urolithiasis in Uyghur children.

High prevalence of pediatric urinary tract stones in Xinjiang Uyghur

The aim of the study was to report the characteristics of urolithiasis in Uyghur patients from Xinjiang, China. The composition of stones collected from 1863 patients in the Uyghur region of Xinjiang was analyzed. The median age of patients was 17 years [25th and 75th percentiles: 2, 36]. The stones were delivered by 1299 males (69.7%) and 564 females (30.3%). Calcium oxalate was the predominant stone component in 42.1% of the patients, followed by ammonium urate in 20.6%. Females had formed more stones of magnesium ammonium phosphate 8.9 vs. 5.6% (p = 0.010) and carbonate apatite 6.2 vs. 3.3% (p = 0.004). In contrast uric acid was more common in males than in females; 21.6 vs. 15.1% (p = 0.001). In this series, pediatric patients (age range 0-18) were more likely to present with a stone (51.5%, p < 0.001). Moreover, the largest number of pediatric stones was recorded in children 1-2 years old (37.9%, p < 0.001). The occurrence of ammonium urate stones was extremely high (52.4%) in children with an age below 1 year. There was a downward trend for ammonium urate with age in both children and adults (p for trend < 0.001, respectively). In contrast the frequency of uric acid declined with age in pediatric patients, but increased in adults (p for trend < 0.001, respectively). This study provides a basis for further considerations on the management of Xinjiang Uyghur patients and emphasize the severity of pediatric stone problems.