Reference Data and T-Scores of Lumbar Skeletal Muscle Area and Its Skeletal Muscle Indices Measured by CT Scan in a Healthy Korean Population. (17th March 2020)

• Record Type: Journal Article
• Authors: Kim, Eun Hee; Kim, Kyung Won; Shin, Yongbin; Lee, Jiwoo; Ko, Yousun; Kim, Ye-Jee; Lee, Min Jung; Bae, Sung-Jin; Park, Sung Won; Choe, Jaewon; Kim, Hong-Kyu
• Editors: Newman, Anne
• Is Part Of: Journals of gerontology. Volume 76:Number 2(2021)
• Page Start: 265
• Page End: 271
• Publication Date: 2020-03-17
• Subjects: Skeletal muscle area -- Skeletal muscle indices -- L3 lumbar spine level -- CT scan -- Asian; Geriatrics -- Periodicals; Gerontology -- Periodicals; 618.97
• DOI: 10.1093/gerona/glaa065
• Languages: English
• ISSNs: 1079-5006

Abstract

Abstract: Background: Although computed tomography (CT) is considered the gold standard for investigating skeletal muscles, diagnostic cutoff points for sarcopenia have not been established. We therefore suggested clinically relevant diagnostic cutoff points for sarcopenia based on reference values of skeletal muscle area (SMA) measured by CT scan in a large-sized healthy Asian population. Methods: This cross-sectional analysis included 11, 845 subjects (7, 314 men, 4, 531 women) who underwent abdominal CT scans in South Korea. SMA including all muscles on the selected axial images of the L3 lumbar vertebrae level was demarcated using predetermined thresholds (−29 to +150 Hounsfield units). SMA indices (height-, weight-, and body mass index [BMI]-adjusted) were calculated. Results: When T-score < −2.0 was used as the cutoff for defining sarcopenia, the sex-specific cutoff points of SMA, SMA/height 2, SMA/weight, and SMA/BMI were 119.3 and 74.2 cm 2, 39.8 and 28.4 cm 2 /m 2, 1.65 and 1.38 cm 2 /kg, and 4.97 and 3.46 in men and women, respectively. In both sexes, the SMA/BMI values peaked in the 20s and decreased gradually. The SMA/BMI yielded the highest diagnostic rate of sarcopenia (4.2% in men, 8.7% in women), while SMA/height 2 provided the lowest yield (2.8% in men, 1.0% in women). Conclusions: This is the first study to report the reference values of SMA and skeletal muscle indices (SMIs) measured on CT scans and to suggest cutoff points for diagnosis of sarcopenia based on T-score in Asian subjects. BMI-adjusted index (SMA/BMI) was the best index of CT-measured SMA to reflect the age-related muscle changes and to maximize the diagnostic yield for sarcopenia.