title: Relationships between direct and indirect measures of central and total adiposity in children: what are we measuring?
abstract: OBJECTIVE
  The relationship between central and total fat measured by anthropometry, dual energy X-ray absorptiometry, and magnetic resonance imaging (MRI) with each other and systolic blood pressure (SBP) was examined.
  
  
  METHODS
  Participants of the Avon Longitudinal Study of Parents and Children were examined at ages 9, 11, 13, and 15 years (n = 3,796-6,567). MRI was available on a subset of children at 11 (n = 156) and 13 (n = 95).
  
  
  RESULTS
  Body mass index (BMI) and waist circumference (WC) were highly correlated (r = 0.84-0.91, across ages), and total body fat mass (TBFM) and trunk fat mass (TFM) were very strongly correlated (r ≥ 0.98). Among boys, BMI vs. WC explained a similar degree of variation in TBFM and TFM (41-71% vs. 43-76%, across age and overweight groups); in girls, BMI accounted for 62-73% variance and WC 47-69%. Adiposity measures were generally similarly correlated with SBP within age groups. Further, the relationship between intra-abdominal adipose tissue (IAAT) volume and adiposity measures did not vary greatly at 11 (0.65-0.67) and 13 (0.64-0.67).
  
  
  CONCLUSIONS
  BMI and WC contain a large amount of overlapping information as evidenced by their high correlation and similarly sized associations with fat mass, SBP, and IAAT. This suggests that WC may be an inadequate marker of central adiposity during childhood.
authors.affiliation: Department of Pediatrics, Boston University School of Medicine, Massachusetts, USA; Section of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA.
authors.forename: Sherman J
authors.initials: SJ
authors.lastname: Bigornia
authors.forename: Michael P
authors.initials: MP
authors.lastname: LaValley
authors.forename: Li L
authors.initials: LL
authors.lastname: Benfield
authors.forename: Andy R
authors.initials: AR
authors.lastname: Ness
authors.forename: P K
authors.initials: PK
authors.lastname: Newby
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat; D016014:Linear Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D055105:Waist Circumference