title: Assessment of total body fat percentage from regional spine and femur DXA measurements among Chinese women and men.
abstract: This study was aimed at determining the correlation between regional body composition and total body fat percentage (TBF%), as measured by dual-energy X-ray absorptiometry (DXA), among Chinese women and men. Men (n=203) and women (n=630), aged 20-87yr, were assessed for height, weight, and body mass index (BMI) and for total body, lumbar spine (L2-L4), and left and right proximal femur fat percentage using DXA. Based on their BMI, male and female subjects were subdivided into 4 groups. For all groups, the TBF% derived from the total body scan was strongly correlated with spine %fat (r range: 0.60-0.96) and the left and right femur %fat (r range: 0.72-0.80 and 0.69-0.83, respectively), as obtained from regional scans. In stepwise regression, TBF% was best assessed by spine %fat, left femur %fat, age, and BMI for both genders (male: R(2)=0.88; female: R(2)=0.84). Equations with spine %fat, age, and BMI also provided good estimates of TBF% (male: R(2)=0.80; female: R(2)=0.75), whereas android and gynoid %fat were predicted with spine %fat and left femur %fat, respectively, and the predicted fat percentage ratio of android to gynoid (A/G) could be obtained from spine %fat and left femur %fat. The cross-validation results showed that the accuracy of all prediction equations was high in the male group, whereas prediction equations with high-to-moderate accuracy were found in the female group. Therefore, for DXA systems that do not offer total body scan, clinicians can assess TBF% using data obtained from regional scans.
authors.affiliation: Department of Nuclear Medicine, First Affiliated Hospital, Jinan University, Guangzhou, China.
authors.forename: Tian-Min
authors.initials: TM
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.forename: Zhong-Man
authors.initials: ZM
authors.lastname: Yuan
authors.forename: Jia-Xuan
authors.initials: JX
authors.lastname: Chen
authors.forename: Jian
authors.initials: J
authors.lastname: Gong
authors.forename: Qiu-Lian
authors.initials: QL
authors.lastname: Wu
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001823:Body Composition; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D013131:Spine / Q000000981:diagnostic imaging