Serum creatinine: a surrogate measurement of lean body mass in children with acute lymphoblastic leukemia.
BACKGROUND
Since creatinine is formed almost exclusively in skeletal muscle, the hypothesis of a relationship between serum creatinine (SC) and lean body mass (LBM), determined by dual-energy X-ray absorptiometry (DXA), was tested.


METHODS
Two cohorts of patients were analyzed: 37 children with acute lymphoblastic leukemia (ALL) and 20 children with primary muscular disorders (PMD). The latter cohort was used as a comparative group. Statistical analyses were performed using linear regressions.


RESULTS
A strong correlation was demonstrated between SC and LBM in the patients with PMD (r = 0.77) and in patients with ALL (r = 0.83 at diagnosis; r = 0.77 on therapy; and r = 0.56 off therapy). The correlation between SC and body size (body mass index) was much weaker (r = 0.38; r = -0.09; r = 0.29 at the successive observations in the ALL cohort and r = 0.05 in the PMD cohort). These data provide support for the initial hypothesis.


CONCLUSIONS
Further investigations with a wider variety of diseases are needed for this will allow the consideration of SC as a general surrogate measure of LBM and consequently of nutritional status.
Sala
Alessandra
A
McMaster University, Hamilton, Ontario L8S 4J9, Canada.
Tarnopolsky
Mark
M
Webber
Colin
C
Norman
Geoff
G
Barr
Ronald
R
D015415:Biomarkers; D001823:Body Composition; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal; D009133:Muscular Atrophy / Q000175:diagnosis* / Q000209:etiology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications*
D015415:Biomarkers; D003404:Creatinine