Urolithiasis in Asian children: Evaluation of metabolic factors

Abstract

This study was conducted to review urolithiasis in Asian children with a focus on urinary metabolic factors. A liter- ature search of Pub Med and Google identified pertinent articles from 20 different Asian countries which were subsequently reviewed. A totally of 12.913 children (M/F ratio of 2.37/1) were enrolled in the studies. Hypercalciuria, hyperuricosuria, hy- peroxaluria, hypocitraturia and decreased urinary magnesium excretion were reported in 652 of 4509 (14.45%), 276 of 3137 (8.8%), 1053 of 3973 (26.5%), 1940 of 2846 (68.2%), 32 of 240 (13.3%) of subjects, respectively. Cystinuria was noted in 112 of 4106 (2.7%) and mixed metabolic abnormalities were found in 175 of 724 (24.2%) patients. Association of urinary tract infection with stone disease was common in our series (2454 of 6430; (38.16) cases). Urologic abnormalities were uncommon and rec- orded in only 447 of 9788 patients (4.5%). The etiology of stone formation was idiopathic in 731 of 2731 (26.8%) patients. Analysis of 3977 stones indicated that 983 (24.9%) were pure Ca stones, whereas 1579 (40%), 411 (10.4%), 38 (0.95%) and 288 (7.35%) were mixed Ca, uric acid or urate, cystine and struvite stones respectively. The study showed that hypocitraturia and hyperoxaluria are the most common metabolic abnormalities. Overall, calcium was the main component of stones with the except that bladder stones were composed of urate or uric acid alone or in combination with calcium. In addition, uric acid stones which are uncommon among American children were frequently reported in Asian children.