Estimation of appendicular muscle mass and fat mass by near infrared spectroscopy in older persons.
OBJECTIVE
Near infrared spectroscopy has been reported to have a high reliability and accuracy in assessing the percentage of body fat. However, whether muscle mass can be accurately estimated using this method has not been established. This study examined whether a near infrared spectroscopy method could estimate appendicular muscle mass and fat mass, with dual-energy X-ray absorptiometry as the standard method for comparison.


METHODS
A total of 20 orthopedic inpatients (mean age 73.2 ± 6.8 years) were recruited for this study. Their body composition was assessed using near infrared spectroscopy and dual-energy X-ray absorptiometry. Appendicular muscle mass and fat mass were estimated from height, weight and optical densities.


RESULTS
The optical densities for the upper arm (biceps, triceps) and forearm (flexor carpi radialis) were significantly correlated with appendicular muscle mass (r = 0.534 to 0.623) or fat mass (r = -0.483 to -0.827). Estimated appendicular muscle mass and fat mass explained 89% and 80% of the variance in the dual-energy X-ray absorptiometry-derived muscle mass and fat mass estimates using height, weight and optical density values of the proximal flexor carpi radialis.


CONCLUSIONS
Near infrared spectroscopy is a useful method to assess not only fat mass, but also muscle mass in older adults.
Section for Health Promotion, Department of Health and Medical Care, Center for Development of Advanced Medicine for Dementia, National Hospital for Geriatric Medicine Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan. yoshida@ncgg.go.jp
Daisuke
D
Yoshida
Hiroyuki
H
Shimada
Atsushi
A
Harada
Yasumoto
Y
Matsui
Yoshihito
Y
Sakai
Takao
T
Suzuki
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019265:Spectroscopy, Near-Infrared