Assessment and correction of skinfold thickness equations in estimating body fat in children with cerebral palsy.
OBJECTIVE
To assess the accuracy of skinfold equations in estimating percentage body fat in children with cerebral palsy (CP), compared with assessment of body fat from dual energy X-ray absorptiometry (DXA).


METHODS
Data were collected from 71 participants (30 females, 41 males) with CP (Gross Motor Function Classification System [GMFCS] levels I-V) between the ages of 8 and 18 years. Estimated percentage body fat was computed using established (Slaughter) equations based on the triceps and subscapular skinfolds. A linear model was fitted to assess the use of a simple correction to these equations for children with CP.


RESULTS
Slaughter's equations consistently underestimated percentage body fat (mean difference compared with DXA percentage body fat -9.6/100 [SD 6.2]; 95% confidence interval [CI] -11.0 to -8.1). New equations were developed in which a correction factor was added to the existing equations based on sex, race, GMFCS level, size, and pubertal status. These corrected equations for children with CP agree better with DXA (mean difference 0.2/100 [SD=4.8]; 95% CI -1.0 to 1.3) than existing equations.


CONCLUSIONS
A simple correction factor to commonly used equations substantially improves the ability to estimate percentage body fat from two skinfold measures in children with CP.
Gurka
Matthew J
MJ
Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA. mgurka@virginia.edu
Kuperminc
Michelle N
MN
Busby
Marjorie G
MG
Bennis
Jacey A
JA
Grossberg
Richard I
RI
Houlihan
Christine M
CM
Stevenson
Richard D
RD
Henderson
Richard C
RC
D015502:Absorptiometry, Photon / Q000379:methods; D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000465:Algorithms; D000886:Anthropometry / Q000379:methods; D002547:Cerebral Palsy / Q000175:diagnosis / Q000473:pathology*; D002648:Child; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012885:Skinfold Thickness