title: Accuracy of skinfold and bioelectrical impedance assessments of body fat percentage in ambulatory individuals with cerebral palsy.
abstract: OBJECTIVE
  This study assessed the accuracy of measurements of body fat percentage in ambulatory individuals with cerebral palsy (CP) from bioelectrical impedance analysis (BIA) and skinfold equations.
  
  
  METHODS
  One hundred and twenty-eight individuals (65 males, 63 females; mean age 12y, SD 3, range 6-18y) with CP (Gross Motor Function Classification System [GMFCS] levels I (n=6), II (n=46), and III (n=19) participated. Body fat percentage was estimated from (1) BIA using standing height and estimated heights (knee height and tibial length) and (2) triceps and subscapular skinfolds using standard and CP-specific equations. All estimates of body fat percentage were compared with body fat percentage from dual-energy X-ray absorptiometry (DXA) scans. Differences between DXA, BIA, and skinfold body fat percentage were analyzed by comparing mean differences. Agreement was assessed by Bland-Altman plots and concordance correlation coefficients (CCC).
  
  
  RESULTS
  BMI was moderately correlated with DXA (Pearson's r=0.53). BIA body fat percentage was significantly different from DXA when using estimated heights (95% confidence intervals [CIs] do not contain 0) but not standing height (95% CI -1.9 to 0.4). CCCs for all BIA comparisons indicated good to excellent agreement (0.75-0.82) with DXA. Body fat percentage from skinfold measurements and CP-specific equations was not significantly different from DXA (mean 0.8%; SD 5.3%; 95% CI -0.2 to 1.7) and demonstrated strong agreement with DXA (CCC 0.86).
  
  
  CONCLUSIONS
  Accurate measures of body fat percentage can be obtained using BIA and two skinfold measurements (CP-specific equations) in ambulatory individuals with CP. These findings should encourage assessments of body fat in clinical and research practices.
authors.affiliation: Medical Staff Research, Shriners Hospital for Children, Lexington, KY, USA.
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Oeffinger
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gurka
authors.forename: Michelle
authors.initials: M
authors.lastname: Kuperminc
authors.forename: Sahar
authors.initials: S
authors.lastname: Hassani
authors.forename: Neeley
authors.initials: N
authors.lastname: Buhr
authors.forename: Chester
authors.initials: C
authors.lastname: Tylkowski
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000503:physiopathology*; D000293:Adolescent; D000886:Anthropometry; D015992:Body Mass Index; D002547:Cerebral Palsy / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D012885:Skinfold Thickness; D013223:Statistics as Topic