title: Upper extremity skeletal muscle mass: potential of measurement with single frequency bioimpedance analysis.
abstract: This study examined the potential of single frequency (50 kHz) BIA for estimation of upper extremity skeletal muscle (SM) mass. Subjects (n = 50) were weight stable adults varying in age (X +/- SD, 51.6 +/- 17 yr) and body mass index (27.2 +/- 5.9 kg/m2). Determinants of arm to arm impedance index (length L; L2/Z) were examined using multiple regression analysis. A good correlation was observed between L2/Z and arm SM estimated by dual-energy X-ray absorptiometry (r = 0.88, p < 0.001). Additional significant model covariates were arm fat mass (p < 0.05), bone mass (p < 0.01), and age (p < 0.001). These findings suggest that upper extremity SM may be rapidly and easily quantified using a simple and inexpensive BIA system combined with appropriate age-adjusted impedance prediction equations.
authors.affiliation: Obesity Research Center, St. Luke's/Roosevelt Hospital, Columbia University, College of Physicians and Surgeons, New York, NY, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: D
authors.initials: D
authors.lastname: Gallagher
authors.forename: J
authors.initials: J
authors.lastname: Grammes
authors.forename: C
authors.initials: C
authors.lastname: Nuñez
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Pietrobelli
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000886:Anthropometry / Q000379:methods; D001132:Arm; D001823:Body Composition; D015992:Body Mass Index; D017097:Electric Impedance; D006801:Humans; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D012044:Regression Analysis; D015203:Reproducibility of Results