Department of Pediatric Nephrology, Children's Hospital Medical Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Pediatr Nephrol. 2012 Jan;27(1):95-9. doi: 10.1007/s00467-011-1936-4. Epub 2011 Aug 4.
Urolithiasis is relatively common in children, and identifiable predisposing factors for stone formation, including metabolic and structural derangements, can be established in most cases. Vesicoureteral reflux (VUR) is a common cause of kidney stone formation. The pathophysiological mechanism of urolithiasis in reflux is related to urinary tract infection and urinary stasis, both of which promote urinary crystal formation, but metabolic causes, such as crystallurias (mostly hypercalciuria), may also be involved in this process. However, few studies on urinary calcium and uric acid excretion in children with VUR have been conducted. We have studied the frequency of hypercalciuria and hyperuricosuria in children with VUR and compared the results with those from a control group. The VUR group comprised 108 children with VUR (19 boys, 89 girls; age range 3 months to 12 years), and the control group comprised 110 healthy children without any history of reflux or urinary tract infection (30 boys, 80 girls; age range 2 months to 12 years). Fasting urine was analyzed for the calcium/creatinine (Ca/Cr) and uric acid/creatinine (UA/Cr) ratios. Hypercalciuria was more frequently diagnosed in the VUR patients than in the control group (21.3 vs. 3.6%; P = 0.0001). Significant differences between the two groups were also found for the mean Ca/Cr and UA/Cr ratios (P = 0.0001 and P = 0.0001, respectively). No differences were found in the urinary Ca/Cr or UA/Cr ratios related to VUR grading or unilateral/bilateral VUR in the patient group, with the exception of those for hypercalciuria and mild VUR (P = 0.03). The association of urinary stones and microlithiasis in the VUR group was 29.6%. Our results demonstrate that the frequency of hypercalciuria and hyperuricosuria was higher in pediatric patients with VUR than in healthy children. Knowing this relationship, preventive and therapeutic interventions for stone formation in VUR could be greatly expanded.
尿石症在儿童中较为常见，大多数情况下可以确定结石形成的可识别诱发因素，包括代谢和结构紊乱。 膀胱输尿管反流 (VUR) 是肾结石形成的常见原因。 反流性尿石症的病理生理机制与尿路感染和尿潴留有关，这两者都促进了尿结晶的形成，但代谢原因，如结晶尿（主要是高钙尿症），也可能参与这一过程。 然而，关于 VUR 儿童尿钙和尿酸排泄的研究很少。 我们研究了 VUR 患儿高钙尿症和高尿酸尿症的发生率，并将结果与对照组进行了比较。 VUR 组包括 108 例 VUR 患儿（男 19 例，女 89 例；年龄 3 个月至 12 岁），对照组包括 110 例无反流或尿路感染史的健康儿童（男 30 例，女 80 例；年龄 2 个月至 12 岁）。 空腹尿液用于分析钙/肌酐 (Ca/Cr) 和尿酸/肌酐 (UA/Cr) 比值。 VUR 患儿高钙尿症的诊断频率高于对照组（21.3%比 3.6%；P=0.0001）。 两组间 Ca/Cr 和 UA/Cr 比值的平均值也存在显著差异（P=0.0001 和 P=0.0001）。 除了高钙尿症和轻度 VUR 外（P=0.03），在患者组中，VUR 分级或单侧/双侧 VUR 与尿钙或 UA/Cr 比值无差异。 VUR 组尿路结石和微结石的关联率为 29.6%。 我们的结果表明，VUR 患儿高钙尿症和高尿酸尿症的发生率高于健康儿童。 了解这种关系，可以大大扩展 VUR 中结石形成的预防和治疗干预措施。
