title: Prevalence of site-specific thigh sarcopenia in Japanese men and women.
abstract: The purpose of this study was to compare the prevalence of severe sarcopenia detected by total skeletal muscle mass (SM) index and of site-specific thigh sarcopenia for differing age groups in men and women. Japanese nonobese men and women aged 20 to 85 (n = 1,994, 55 % women) had muscle thickness (MTH) measured by ultrasound at six sites on the anterior and posterior aspects of the body. SM was estimated from ultrasound-derived prediction equations. Site-specific thigh sarcopenia was calculated using ultrasound-measured MTH at the anterior and posterior aspects of the thigh (MTH ratio, anterior 50 %/posterior 50 % thigh MTH (A50/P50 MTH)). Sarcopenia was defined as a SM index (SM divided by height(2)) of >2 standard deviations (SD) below the mean for young adults. Site-specific thigh sarcopenia was defined as a ratio of A50/P50 MTH of >2 SD below the mean for young adults. Age was inversely correlated to SM index and A50/P50 MTH in men (r = -0.480 and r = -0.522) and women (r = -0.243 and r = -0.516). The prevalence rate of sarcopenia was less than 3 % for women under the age of 60, 7 % for ages 60-69, and 24 % for ages 70-80. In men, the prevalence rate of sarcopenia was less than 7 % under the age of 50, 18 % for ages 50-59, 33 % for ages 60-69, and 47 % for ages 70-85. Compared to the sarcopenia estimated by SM index, there was a higher prevalence of site-specific thigh sarcopenia observed in both sexes. These results suggest that site-specific thigh sarcopenia appears before it is able to be detected at the whole body level.
authors.affiliation: Department of Health, Exercise Science & Recreation Management, University of Mississippi, 215 Turner Center, Oxford, MS, 38677, USA, t12abe@gmail.com.
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Robert S
authors.initials: RS
authors.lastname: Thiebaud
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Loenneke
authors.forename: Mark
authors.initials: M
authors.lastname: Loftin
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Fukunaga
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D001823:Body Composition; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D015995:Prevalence; D055948:Sarcopenia / Q000453:epidemiology* / Q000503:physiopathology*; D013848:Thigh