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.
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.
Siervo
M
M
MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK. mario.siervo@mrc-hnr.cam.ac.uk
Davies
A A
AA
Jebb
S A
SA
Jalil
F
F
Moore
S E
SE
Prentice
A M
AM
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