title: Assessment of appendicular skeletal muscle mass by bioimpedance in older community-dwelling Korean adults.
abstract: It is crucial to investigate age-related body composition changes in geriatric medicine. Bioelectrical impedance analysis (BIA) is easy to perform, non-invasive, relatively inexpensive, and portable. However, the accuracy of measurement by BIA is questionable. To develop and cross-validate the predictive equation for estimated appendicular skeletal muscle mass (ASM) using BIA in older community-dwelling Korean adults, we include two cohorts: study participants aged 65-80 years in the Ansung cohort for the Korean Health and Genome Study (men, n=285; women, n=435) used as equation-generating group, and Korean Longitudinal Study of Health Aging (KLoSHA) as cross-validation group (men, n=202; women, n=208). Dual energy X-ray absorptiometry (DXA) and BIA were performed in both cohorts. Using multiple linear regression analysis, we drew a predictive equation for DXA-measured ASM by BIA resistance. From DXA and BIA measurements in the Ansung cohort, we generated the estimated equation ASM (kg)=[(Ht(2)/R×0.104)+(age×-0.050)+(gender×2.954)+(weight×0.055)]+5.663 where Ht is height in centimeters; R is BIA resistance in 250Ω; for gender, men=1 and women=0; and age is in years. We validated this equation in the KLoSHA. The r(2) of the estimated ASM was 0.890. This BIA equation provides valid estimates of ASM in older Korean adults.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Soo
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Ki Woong
authors.initials: KW
authors.lastname: Kim
authors.affiliation: Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lim
authors.affiliation: Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Nam H
authors.initials: NH
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyong Soo
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea. Electronic address: janghak@snu.ac.kr.
authors.forename: Hak Chul
authors.initials: HC
authors.lastname: Jang
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000886:Anthropometry; D044466:Asian People / Q000706:statistics & numerical data; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D015331:Cohort Studies; D017097:Electric Impedance; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D016014:Linear Models; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D012044:Regression Analysis; D015203:Reproducibility of Results; D056910:Republic of Korea; D012680:Sensitivity and Specificity
keywords: Appendicular skeletal muscle mass; Bioelectrical impedance analysis; Dual energy X-ray absorptiometry