Open AccessEthnic variation in body composition assessment in a sample of adolescent girls
Author(s) -
MEYER KATIE A.,
FRIEND SARAH,
HANNAN PETER J.,
HIMES JOHN H.,
DEMERATH ELLEN W.,
NEUMARKSZTAINER DIANNE
Publication year - 2011
Publication title -
international journal of pediatric obesity
Language(s) - English
Resource type - Journals
eISSN - 1747-7174
pISSN - 1747-7166
DOI - 10.3109/17477166.2011.596841
Subject(s) - medicine , bioelectrical impedance analysis , body mass index , fat mass , dual energy x ray absorptiometry , demography , fat free mass , body fat percentage , linear regression , dual energy , lean body mass , anthropometry , mass index , bone mineral , body weight , statistics , osteoporosis , mathematics , sociology
Objective . To compare body composition assessment by bioelectrical impedance analysis (BIA) and dual‐energy X‐ray absorptiometry (DXA) in a multiethnic sample of adolescent girls. Method . Data were from a physical activity intervention study among 254 14–20‐year‐old sedentary American girls, including 69 whites, 74 blacks, 42 Hispanics, and 69 Asians. Height and weight were objectively measured. Body composition was assessed using a foot‐to‐foot BIA and a fan‐beam DXA. We calculated ethnic‐specific estimates of percentage body fat (BF%), fat mass (FM), fat mass index (FMI), fat‐free mass (FFM), and fat‐free mass index (FFMI) from BIA and DXA. We used Bland‐Altman plots to examine ethnic‐specific agreement between BIA and DXA, and used linear regression to test whether the BIA‐DXA difference varied across the mean. Results . Compared to DXA, BIA estimates of fat measures (BF%, FM, and FMI) were lower and lean tissue measures (FFM and FFMI) higher. For example, the BIA‐estimated BF% was lower than the DXA estimate by between 4.9% (95% CI: −5.9, −3.9) in blacks and 8.7% (−7.0, −5.0) in Asians, with large limits of agreement (−15.4 to −5.4 in blacks and −16.8 to −0.4 in Asians). Regression analysis showed that BIA‐DXA differences were not constant across means for any body composition measure among Asians or for any measure except BF% among whites. Conclusion . Compared to DXA, BIA yielded lower estimates of adiposity in a multiethnic adolescent sample. BIA‐DXA differences varied by ethnicity, and across mean body composition values for some ethnicities.