Metabolic factors associated with urinary calculi in children.
BACKGROUND
We aimed to identify metabolic and anatomical abnormalities present in children with urinary calculi.


METHODS
Metabolic evaluation was done in 142 pediatric calculus formers. Evaluation included serum biochemistry; measurement of daily excretion of urinary calcium, uric acid, oxalate, citrate, and magnesium (in older children); and measurement of calcium, uric acid, oxalate, and creatinine in random urine samples in nontoilet-trained patients. Urinary tests for cystinuria were also performed. All of the patients underwent renal ultrasonography.


RESULTS
Sixty-one patients (42.7%) had metabolic abnormalities. Anatomical abnormalities were found in 12 patients (8.4%). Three children (2.1%) had infectious calculi, and 3(2.1%) had a combination of metabolic and anatomic abnormalities. In 66 children (46.2 %) we did not find any reasons for calculus formation (idiopathic). Urinalysis revealed hypercalciuria in 25 (17.6%), hyperuricosuria in 23 (16.1%), hyperoxaluria in 17 (11.9%), cystinuria in 9 (6.3%), hypocitraturia in 3 (2.1%), and low urinary magnesium level in 1 (0.7%) patients. Sixteen patients (11.2%) had mixed metabolic abnormalities.


CONCLUSIONS
Metabolic abnormalities are common in pediatric patients with urinary calculi. In our study, calcium and uric acid abnormalities were the most common, and vesicoureteral reflux seemed to be the most common urological abnormality which led to urinary stasis and calculus formation.
Naseri
Mitra
M
Department of Pediatrics, Dr Sheikh Children Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. naserim@mums.ac.ir
Varasteh
Abdol Reza
AR
Alamdaran
Seied Ali
SA
D000293:Adolescent; D002118:Calcium / Q000097:blood; D002648:Child; D002675:Child, Preschool; D019343:Citric Acid / Q000652:urine; D003555:Cystinuria / Q000453:epidemiology / Q000378:metabolism; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology / Q000378:metabolism; D006959:Hyperoxaluria / Q000453:epidemiology / Q000378:metabolism; D033461:Hyperuricemia / Q000453:epidemiology / Q000378:metabolism; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000453:epidemiology / Q000378:metabolism; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology* / Q000378:metabolism*; D011446:Prospective Studies; D012307:Risk Factors; D014527:Uric Acid / Q000097:blood; D014545:Urinary Calculi / Q000453:epidemiology* / Q000378:metabolism*; D014718:Vesico-Ureteral Reflux / Q000453:epidemiology / Q000378:metabolism
D014527:Uric Acid; D019343:Citric Acid; D002118:Calcium