Pediatric Nephrology Unit, Clinics Hospital, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil.
J Urol. 2013 Apr;189(4):1493-7. doi: 10.1016/j.juro.2012.11.107. Epub 2012 Nov 27.
Due to environmental and social changes (and possibly obesity) as new risk factors for stone formation in adults and changes in imaging techniques, we assessed whether etiologies of primary pediatric urolithiasis have changed, and if relationships exist between the condition and obesity or imaging technique.
All pediatric patients with documented primary urolithiasis who underwent serum and 24-hour urine analyses between 1999 and 2010 were evaluated. Age at diagnosis, gender, body mass index and imaging technique were recorded.
Of the 222 patients (48% male) all had normal serum creatinine, electrolytes and minerals. Primary pediatric urolithiasis was diagnosed by ultrasound in 73% of cases and computerized tomography in 27%. Mean ± SD annual incidence of urolithiasis per 1,000 clinic visits increased from 2.4 ± 1.5 in the first half of the study period to 6.2 ± 2.1 in the second half (p <0.005). Mean ± SD age at diagnosis was 11.8 ± 3.8 years and body mass index was 21.7 ± 5.7 (rate of overweight 15%). A total of 140 patients had urine output less than 1.0 ml/kg per hour, with this being the only abnormality in 54. Hypercalciuria was observed in 46% of patients, hypocitraturia in 10% and high calcium-to-citrate ratio in 51%. Mild absorptive hyperoxaluria was noted in 3 patients and hyperuricosuria in 11, with all 14 exhibiting at least 1 additional abnormality. Cystinuria was present in 1 patient. No etiology was identified in 20 patients (9.0%).
Oliguria and hypercalciuria continue to be the most common etiologies of pediatric primary urolithiasis, followed by hypocitraturia. The recent increase in stone incidence is unlikely due to increased use of computerized tomography. Incidence of obesity was not higher than in the general population. Hyperoxaluria and cystinuria are rare, and thus might not be indicated in the initial analysis.
由于环境和社会变化（可能还有肥胖）成为成人结石形成的新危险因素，以及成像技术的变化，我们评估了小儿原发性尿石症的病因是否发生了变化，以及该病与肥胖或成像技术之间是否存在关系。
评估了 1999 年至 2010 年间所有接受过血清和 24 小时尿液分析的有记录的原发性小儿尿石症患者。记录了诊断时的年龄、性别、体重指数和成像技术。
222 例患者（48%为男性）血清肌酐、电解质和矿物质均正常。73%的病例通过超声诊断为原发性小儿尿石症，27%通过计算机断层扫描诊断。每 1000 次就诊中尿石症的年发生率从研究前半段的 2.4±1.5 增加到后半段的 6.2±2.1（p<0.005）。诊断时的平均年龄±标准差为 11.8±3.8 岁，体重指数为 21.7±5.7（超重率为 15%）。共有 140 例患者每小时尿量小于 1.0ml/kg，其中 54 例仅有这一异常。46%的患者存在高钙尿症，10%的患者存在低柠檬酸尿症，51%的患者存在高钙与柠檬酸比值。3 例存在轻度吸收性高草酸尿症，11 例存在高尿酸尿症，14 例均存在至少 1 种其他异常。1 例存在胱氨酸尿症。20 例（9.0%）患者未确定病因。
少尿和高钙尿症仍然是小儿原发性尿石症最常见的病因，其次是低柠檬酸尿症。结石发病率的最近增加不太可能是由于计算机断层扫描使用增加所致。肥胖的发病率并不高于一般人群。高草酸尿症和胱氨酸尿症很少见，因此在初始分析中可能不是必需的。
