Metabolic evaluation of children with urolithiasis: are adult references for supersaturation appropriate?
OBJECTIVE
We determined the incidence of urinary stone risk factors in pediatric patients with urolithiasis.


METHODS
Between 1998 and 2001, 71 children with urolithiasis at 2 pediatric institutions underwent metabolic evaluation. The 24-hour urine samples were analyzed outside central laboratory using adult and known pediatric references. Supersaturation and traditional metabolic parameters were determined and compared.


RESULTS
All patients had metabolic abnormalities. Calcium related abnormalities were present in 92% of children, calcium oxalate supersaturation was abnormal in 69%, calcium phosphate supersaturation was elevated in 70% and traditional calcium parameters were abnormal in 80%. While 11% of the patients had abnormal calcium phosphate or oxalate supersaturation with normal traditional calcium parameters, 10% had normal calcium oxalate or phosphate supersaturation with abnormal traditional calcium parameters. Low urinary volume was identified in 75% of the children.


CONCLUSIONS
Metabolic abnormalities are extremely common in pediatric patients with urolithiasis. Calcium related abnormalities are the most common abnormality. Urinary supersaturation values are complementary to traditional metabolic parameters and may be more sensitive predictors of recurrent stone risk. It is important to establish pediatric reference ranges to interpret these data more accurately.
Battino
Benjamin S
BS
Division of Pediatric Urology, Children's Hospital Medical Center, Cinncinnati, Ohio 45229, USA.
DeFOOR
William
W
Coe
Frederic
F
Tackett
Leslie
L
Erhard
Michael
M
Wacksman
Jeffrey
J
Sheldon
Curtis A
CA
Minevich
Eugene
E
D000293:Adolescent; D000328:Adult; D002129:Calcium Oxalate / Q000652:urine; D002130:Calcium Phosphates / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010070:Oxalates / Q000652:urine; D012307:Risk Factors; D014527:Uric Acid / Q000652:urine; D014545:Urinary Calculi / Q000652:urine*
D002130:Calcium Phosphates; D010070:Oxalates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D002129:Calcium Oxalate; D014527:Uric Acid; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous