title: Ethnic differences in the association between body mass index and impedance index (Ht2/Z) in adult women and men using a leg-to-leg bioimpedance method.
abstract: BACKGROUND
  Ethnic differences in the association between body mass index (BMI) and body fat suggest that body composition varies across ethnic groups.
  
  
  OBJECTIVE
  To investigate the association between impedance index - a measure of tissue resistivity - and BMI in adults of different ethnic groups (Asian Indians, West Africans and White Caucasians) living in their native countries.
  
  
  METHODS
  Male (n=329) and female (n=277) adult subjects (18-50 years) living in urban areas in the UK, The Gambia and Pakistan were studied. Body weight and height were measured and BMI calculated. The same leg-to-leg bioimpedance instrument was used in each study and impedance index (height(2) (cm)/impedance (Omega)) used as measure of tissue resistivity.
  
  
  RESULTS
  In women, Asian Indians and West Africans had a significantly greater increase in impedance index per unit increase in BMI compared with white Caucasians (P<0.001). In men, Asian Indians had a significantly lower impedance index compared with West Africans and white Caucasians (P<0.001).
  
  
  CONCLUSIONS
  Different ethnic groups may have different tissue resistivity for the same BMI indicative of systematic differences in body composition.
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK. mario.siervo@mrc-hnr.cam.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Siervo
authors.forename: A A
authors.initials: AA
authors.lastname: Davies
authors.forename: S A
authors.initials: SA
authors.lastname: Jebb
authors.forename: F
authors.initials: F
authors.lastname: Jalil
authors.forename: S E
authors.initials: SE
authors.lastname: Moore
authors.forename: A M
authors.initials: AM
authors.lastname: Prentice
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D044383:Black People; D001823:Body Composition / Q000502:physiology*; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D017097:Electric Impedance; D005006:Ethnicity; D005121:Extremities / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D044465:White People