title: Age-Related Changes in Segmental Body Composition by Ethnicity and History of Weight Change across the Adult Lifespan.
abstract: This study assessed age-related changes in body composition (specifically in trunk fat and appendicular lean masses), with consideration of body mass index (BMI) at age 20 years (BMI reference age, "BMIref"), ethnicity and lifetime weight change history. A cross-sectional dual-energy X-ray absorptiometry-based dataset was extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) 1999-2004. Only European-American and African-American subjects were used (2705 men, 2527 women). For each gender and ethnicity, 6 analytic cases were considered, based on three BMIref categories (normal, overweight and obese, being 22, 27 and 30 kg/m², respectively) and two weight contexts (stable weight or weight gain across the lifespan). A nonparametric model was developed to investigate age-related changes in body composition. Then, parametric modelling was developed for assessing BMIref- and ethnicity-specific effects during aging. In the stable weight, both genders' and ethnicities' trunk fat (TF) increased gradually; body fat (BF) remained stable until 40 years and increased thereafter; trunk lean (TL) remained stable, but appendicular lean (APL) and body lean (BL) declined from 20 years. In the weight gain context, TF and BF increased at a constant rate, while APL, TL and BL increased until 40-50 years, and then declined slightly. Compared with European-American subjects of both genders, African-American subjects had lower TF and BF masses. Ethnic differences in body composition were quantified and found to remain constant across the lifespan.
authors.affiliation: Department of Scientific Research Project, Affiliated Zhongshan Hospital of Dalian University, 116001 Dalian, China. simiao_tian@sina.com.
authors.forename: Simiao
authors.initials: S
authors.lastname: Tian
authors.affiliation: Unité Mixte de Recherche 1397, Laboratoire Carmen, Université Lyon 1, INSERM U1060, INSA de Lyon, Universités Rockefeller et Charles Merieux Lyon-sud, 69000 Lyon, France. beatrice.morio@lyon.inra.fr.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Morio
authors.affiliation: Unité de Recherche Mathématiques et Informatique Appliquées, Institut National de Recherche Agronomique, F-78352 Jouy-en-Josas, France. jean-baptiste.denis@jouy.inra.fr.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Denis
authors.affiliation: Unité de Nutrition Humaine, Unité Mixte de Recherche 1019, Institut National de Recherche Agronomique, F-63000 Clermont-Ferrand, France. laurence.mioche63@gmail.com.
authors.forename: Laurence
authors.initials: L
authors.lastname: Mioche
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000328:Adult; D001741:Black or African American; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009765:Obesity / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D015430:Weight Gain / Q000208:ethnology*; D044465:White People; D055815:Young Adult
keywords: aging; body composition; multivariate modelling