Review Article

Muscle Mass Assessment in Sarcopenia: A Narrative Review

Isao Muraki
Public Health, Osaka University Graduate School of Medicine, Suita, Japan

Corresponding author: Isao Muraki,

DOI: 10.31662/jmaj.2023-0053

Received: March 30, 2023
Accepted: June 1, 2023
Advance Publication: September 29, 2023
Published: October 16, 2023

Cite this article as:
Muraki I. Muscle Mass Assessment in Sarcopenia: A Narrative Review. JMA J. 2023;6(4):381-386.


Sarcopenia is a condition characterized by age-related muscle loss and dysfunction. Over the past decade, several working groups have developed diagnostic criteria for sarcopenia, including muscle mass, grip strength, and gait speed measurements. However, there is debate over which muscle mass indicator is the most appropriate. Some groups used appendicular lean mass divided by height squared, whereas others used appendicular lean mass divided by body mass index. In addition, the association between muscle mass and long-term health outcomes is inconsistent. As a result, some experts question the necessity of using muscle mass as a diagnostic criterion for sarcopenia. This review summarizes the measurement methods and muscle mass indicators of previous studies, highlighting issues with past muscle mass assessments.

Key words: sarcopenia, muscle mass, measurement


Three decades ago, sarcopenia was first conceptualized as age-related muscle loss and dysfunction (1). Since 2010, sarcopenia has been defined as the combination of muscle mass, grip power, and gait speed by the European Society for Clinical Nutrition and Metabolism (ESPEN) Special Interest Group (2) and the European Working Group on Sarcopenia in Older People (EWGSOP) (3). The definition by the Asian Working Group for Sarcopenia was determined 5 years later, according to the EWGSOP definition (4). Although the definitions by EWGSOP and the Asian Working Group for Sarcopenia included skeletal muscle mass index (SMI) which was calculated as appendicular lean mass (ALM) divided by height squared (3), (4), the Foundation for the National Institutes of Health (FNIH) sarcopenia project adopted ALM divided by body mass index (BMI) instead of SMI (5). In the last decade, many sarcopenia working groups have developed and updated the diagnosis criteria for sarcopenia (Table 1) (2), (3), (4), (5), (6), (7), (8), (9), (10), (11). However, the best muscle mass indicator remains unknown, possibly due to inconsistency in the association with long-term health outcomes, including physical function and mortality. Furthermore, the recent criteria for sarcopenia have shifted toward dynapenia by omitting muscle mass criteria from essential sarcopenia criteria (11). During the process of achieving consensus on the recent criteria of the Sarcopenia Definition and Outcomes Consortium, expert opinions regarding whether muscle mass is essential for diagnosing sarcopenia have been controversial.

Table 1. Definition of Sarcopenia.

Consensus group Year A. Muscle mass B. Muscle strength C. Physical performance Diagnosis
ESPEN-SIG (2) 2010 ALM/weight ≤ −2 SD of 18-39 years in the same sex and ethnicity - Gait speed <0.8 m/s in 4-m walk C and A
EWGSOP (3) 2010 ALM/height2 (kg/m2) Grip strength (kg) Gait speed ≤0.8 m/s (B and/or C) and A
≤5.67 (F), ≤7.23 (M) <20 (F), <30 (M)
IWGS (6) 2011 ALM/height2 (kg/m2) - Gait speed ≤1.0 m/s C and A
≤5.67 (F), ≤7.23 (M)
SCWD (7) 2011 ALM/height2 ≤ −2 SD of 20 and 30 years in the same ethnicity - Gait speed ≤1.0 m/s C and A
400-m walk ≥6 min or fail
AWGS (4) 2014 ALM/height2 (kg/m2) Grip strength (kg) Gait speed <0.8 m/s in 6-m walk (B and/or C) and A
DEXA: ≤5.40 (F), ≤7.00 (M) <18 (F), <26 (M)
BIA: ≤5.70 (F), ≤7.00 (M)
FNIH (5) 2014 ALM/BMI (m2) Grip strength (kg) - B and A
≤0.512 (F), ≤0.789 (M) <16 (F), <26 (M)
EWGSOP (9) 2018 ALM (kg) <15 (F), <20 (M) Grip strength (kg) Gait speed ≤0.8 m/s B and A
ALM/height2 (kg/m2) <16 (F), <27 (M) Short Physical Performance Battery ≤8 points
<5.5 (F), <7.0 (M) Chair stand
>15 s/five rises Timed Up & Go test ≥20 s
400-m walk ≥6 min or fail
AWGS (10) 2019 ALM/height2 (kg/m2) Grip strength (kg) Gait speed <1.0 m/s (B and/or C) and A
DEXA: ≤5.4 (F), ≤7.0 (M) <18 (F), <28 (M) Chair stand ≥12 s/five rises
BIA: ≤5.7 (F), ≤7.0 (M) Short Physical Performance Battery ≤9 points
SDOC (11) 2020 - Grip strength (kg) Gait speed <0.8 m/s B and C
<20 (F), <35.5 (M)
ALM, appendicular lean mass; AWGS, Asian Working Group for Sarcopenia; BIA, bioelectric impedance analysis; BMI, body mass index; DEXA, dual-energy X-ray absorptiometry; ESPEN-SIG, European Society for Clinical Nutrition and Metabolism Special Interest Group; EWGSOP, European Working Group on Sarcopenia in Older People; FNIH, Foundation for the National Institutes of Health; IWGS, International Working Group on Sarcopenia; SCWD, Society for Sarcopenia, Cachexia, and Wasting Disorders; SDOC, Sarcopenia Definition and Outcomes Consortium.

To prevent sarcopenia, an efficient mass screening method should be established. Physical performance tests require extensive resources, such as longer test time and larger test space. In addition, the variations in test results can be caused by the participant’s condition, education effect in repeated measures, and skill levels of technicians, compared with muscle mass measurement. Thus, physical performance tests may not be feasible for mass screening. The EWGSOP recommended using the SARC-F questionnaire for case finding in their revised definition of sarcopenia (9). However, SARC-F and other screening questionnaires have low sensitivity and high specificity, suggesting that many true cases may be missed (12). Contrarily, muscle mass measurements can be feasible, objective, and time-saving tests with high accuracy for sarcopenia mass screening. In this review, we summarize the measurement methods and muscle mass indicators to highlight the issues with previous assessments.

Measurement Methods of Skeletal Muscle Mass

Skeletal muscle mass is measured using various direct and indirect methods. The major direct methods include computed tomography (CT), magnetic resonance imaging (MRI), dual-energy X-ray absorptiometry (DEXA), and skeletal muscle ultrasound. On the other hand, the major indirect methods include bioelectric impedance analysis (BIA) and D3-creatine dilution methods. Each measurement method has advantages and disadvantages, which are presented in Table 2.

Table 2. Summary of Measurement Methods of Skeletal Muscle Mass.

Measurement methods Time Equipment Cost Target muscles Measures Cutoff Adverse effect
Direct methods
 Computed tomography (CT) Short Fixed High Specific muscle Cross-sectional area No High-level radiation
 Magnetic resonance imaging (MRI) Long Fixed High Whole-body, components, specific muscle Cross-sectional area No -
 Dual-energy X-ray absorptiometry (DEXA) Short Fixed Low Whole-body, components ALM Yes Low-level radiation
 Skeletal muscle ultrasound Short Portable Low Specific muscle Muscle thickness No -
Muscle thickness
Indirect methods
 Bioelectric impedance analysis (BIA) Short Portable Low Whole-body, components ASM Yes -
 D3-creatine dilution method Long - High Whole-body Creatine pool size No -
ALM, appendicular lean mass; ASM, appendicular skeletal muscle mass.

Computed tomography

CT is an assessment method that highly distinguishes skeletal muscle from other components, including bone and connective tissues; it is frequently used as the gold standard measurement method for muscle mass (13). The advantage of CT is its ability to simultaneously measure both the skeletal muscle area (quantity) and density (quality), which reflects intramuscular adiposity links to muscle function. However, it requires the use of large equipment and exposes patients to high-level radiation. Radiation exposure increases the difficulty of using CT for the whole-body measurement of skeletal muscle mass among healthy individuals. However, existing CT images for other purposes can be reanalyzed in a clinical setting for skeletal muscle assessment. The prevalence of sarcopenia and its impact on adverse clinical outcomes have been investigated using CT among patients undergoing routine CT imaging, particularly those with cancer (14), (15), (16). Generally, the skeletal muscle is assessed via CT at the 3rd lumbar vertebra level (17) but is dependent on the routine CT imaging range, such as the cervical vertebra for head and neck cancers or thoracic vertebra for lung cancer (18).

Magnetic resonance imaging

MRI is another high-resolution method for skeletal muscle assessment and is considered a gold standard (13). Because MRI can capture several weighted images, it enables a more thorough examination of muscle quantity and quality than CT. Furthermore, MRI has no radiation exposure, giving it an advantage over CT. However, MRI requires participants to remain still for a longer period during imaging. High cost and the lack of a reference value for diagnosing sarcopenia are also important limitations of MRI.

Dual-energy X-ray absorptiometry

DEXA is the most commonly used measurement method for skeletal muscle mass (19). Compared with CT, MRI, and the four-compartment model, DEXA has a stronger and more concurrent validity (correlation coefficient: r > 0.91) (13). By emitting two different energy X-rays, DEXA measures lean mass in the whole body and body components as the subtraction of bone and fat. Skeletal muscle and connective tissue make mass (20). Therefore, DEXA cannot directly determine skeletal muscle mass or assess muscle quality as CT can. However, DEXA has significantly lower radiation exposure than CT but has limited portability for skeletal muscle mass measurement compared with portable devices.

Skeletal muscle ultrasound

Skeletal muscle ultrasound is an inexpensive method for bedside muscle assessment that has several benefits, including no radiation exposure, low cost, and portability. It can assess muscle thickness, cross-sectional area, echo intensity, pennation angle, and fascicle length. However, the accuracy and comparability of skeletal muscle ultrasound measures could vary between technicians; guidelines have been published to standardize the measurement technique (21). It is impractical to sequence whole body or appendicular muscle mass using skeletal muscle ultrasound due to the long sequence time. Thus, muscle mass prediction formulas have been developed using selected muscle thickness measured by skeletal muscle ultrasound and validated compared with DEXA (22), (23), (24) and MRI (25). Skeletal muscle ultrasound is a reliable and validated method for muscle mass measurement in the diagnosis of sarcopenia (26), (27).

Bioelectrical impedance analysis

BIA is an indirect measurement method for muscle mass; it measures the impedance of body components using a combination of electrode positions and electric currents with single or multiple frequencies, as skeletal muscle and fat mass have different impedances (28). BIA has no radiation exposure and is feasible for use in any setting owing to its portability. However, it has the following limitations: some conditions, such as edema, increases measurement errors, and implant medical devices are not allowed for testing. The validity and reliability in estimating muscle mass are high for multiple-frequency BIA and moderate for single-frequency BIA (13). To improve validity, many equations have been proposed that modele age, sex, and anthropometric variables (29). BIA also measures phase angle, which may reflect muscle quality and function (30). Lower phase angle has been associated with lower muscle functions (31).

Creatine-(methyl-d3) (D3-creatine) dilution method

The D3-creatine dilution method indirectly assesses the skeletal muscle mass by linking it to total-body creatine pool size (32). The skeletal muscle is the largest creatine pool in the whole body. After creatine is absorbed from the intestine, it is diluted in the creatine pool and excreted in urine by the kidney. Then, creatine isotope (D3-creatine) diluted in the creatine pool and total-body creatine pool can be estimated by measuring the urinary concentration ratio of D3-creatine to total creatine. D3-creatine dilution relies on four assumptions to accurately measure the total-body creatine pool. First, D3-creatine is absorbed without any loss. Second, it is completely diluted in the creatine pool before excretion. Third, it is distributed only in the skeletal muscle. Fourth, its distribution is consistent in all skeletal muscles and is not altered by any condition. However, because the last three assumptions are not completely true, errors in the measurement of skeletal muscle mass occur when using the D3-creatine dilution method. Although muscle mass measured by the D3-creatine dilution method is strongly correlated with the MRI- and DEXA-measured muscle mass, the D3-creatine dilution method measures muscle mass smaller than DEXA (33). Furthermore, lower and decreased muscle mass measured by the D3-creatine dilution method is associated with worsened physical function, and a higher risk of physical disability and mortality, but DEXA-measured muscle mass adjusted for height is not (34), (35), (36), (37).

Muscle Mass Indicators

Muscle mass can be measured using three indicators: cross-sectional area, thickness, and mass weight. To accurately assess muscle mass, various indicators have been created. However, no single indicator has a consensus with the definition of sarcopenia. Different muscle mass indicators can be used depending on the definitions of sarcopenia, including ALM, appendicular skeletal muscle mass (ASM), relative skeletal muscle mass (%ALM), SMI, and ALM/BMI.


ALM and ASM are the crude measures of lean and muscle mass, respectively. ALM is the lean mass weight of all upper and lower limbs measured by DEXA. Meanwhile, ASM is the skeletal muscle mass in all upper and lower limbs estimated by BIA. Owing to their similarities and shared uses, ALM is used as a common term for ALM and ASM in this review. Research has demonstrated that lower ALM is associated with a higher risk of mortality but not disability in US men (38). In US women, no association between ALM and mortality and disability was observed. It is noteworthy that the association of ALM with disability and mortality varies across different populations (39). Therefore, ALM was added to the revised sarcopenia definition of EWGSOP as a muscle loss measure (9). In that definition, the cutoff value of ALM was below 20 kg for men and below 15 kg for women. Nevertheless, it is noteworthy that ALM has a strong positive correlation with height and weight (40).

Adjustment for anthropometry in muscle mass assessment

There are several approaches to adjusting for anthropometry in muscle mass assessment. The three major parameters are SMI, %ALM, and ALM/BMI. SMI was first proposed by Baumgartner RN et al. in 1998 (41). Due to the strong correlation between muscle mass and height, SMI is measured as ALM divided by height squared, which is the best variable to minimize the correlation between ALM and height. This indicator still has a moderate positive correlation with weight and BMI (42). Although SMI is most frequently accepted as a muscle loss indicator in the definition of sarcopenia, lower SMI was associated with higher mortality but not with disability among men and women in the US (38) and Japan (39). Conversely, an inverse association of SMI was apparent with the risk of disability and mortality among men and women in another Japanese cohort (43).

Focusing on weight components, %ALM and ALM/BMI were also used to assess muscle quantities. %ALM was proposed by Janssen I et al. to adjust for nonskeletal muscle mass (8), calculated as ALM divided by the whole-body weight. %ALM is a muscle loss component of sarcopenia defined by the ESPEN Special Interest Group (2). Because whole-body weight is associated with height and fat mass, %ALM can be partially adjusted for height-related components and fat mass. However, a modest inverse correlation was observed between %ALM and weight and BMI (42). To date, the association between %ALM and long-term health outcomes has not been well examined. In a Japanese study, no association was reported after age adjustment (39).

The FNIH sarcopenia project recommended using ALM/BMI as a muscle loss measure (5). Because lower SMI was not strongly associated with physical function (44), (45), they determined which muscle mass indicator strongly predicts slow gait speed (<0.8 m/s) and found that ALM was the best muscle mass indicator predicting slow gait speed in men but not in women (46). As ALM/BMI consistently predicted worse physical performance in both sexes, they accepted ALM/BMI as muscle loss indicator in their sarcopenia definition (5). However, ALM/BMI was not associated with the risk of disability and mortality among Japanese individuals (39).

In addition, the residual of linear regression modeling was analyzed using ALM as the dependent variable and height and total fat mass as the explanatory variables (44). A positive association between the residual and leg function was observed in both men and women, whereas a positive association between the residual and SMI was seen only in men. However, the reference formula may not be generalizable to other populations. Further investigation is required to create the ideal reference formula.


All muscle indicators strongly correlate with body size; thus, we used SMI, %ALM, and ALM/BMI to adjust for height, weight, or BMI. However, even after adjusting for these variables, the muscle indicators remained moderately correlated with body size. Therefore, the use of muscle indicators as part of the sarcopenia diagnosis criteria may have biased the diagnosed sarcopenia from the true sarcopenia. Furthermore, the residual correlation between adjusted muscle indicators and body size may interfere with the appropriate assessment of muscle loss. Further research on muscle mass assessment is necessary to establish a clear definition of sarcopenia.

Article Information

This article is based on the study, which received the Medical Research Encouragement Prize of The Japan Medical Association in 2022.

Conflicts of Interest


Sources of Funding

This work was supported by JSPS KAKENHI grant number 22H03351.

Author Contributions

IM contributed to the search of previous publications and writing of the whole manuscript.

Approval by Institutional Review Board (IRB)

Because this is not a research of human beings, approval from the institutional review board is not required.


  1. 1.

    Rosenberg IH. Sarcopenia: origins and clinical relevance. J Nutr. 1997;127(5 Suppl):990S-1S.

  2. 2.

    Muscaritoli M, Anker SD, Argilés J, et al. Consensus definition of sarcopenia, cachexia and pre-cachexia: joint document elaborated by Special Interest Groups (SIG) “cachexia-anorexia in chronic wasting diseases” and “nutrition in geriatrics”. Clin Nutr. 2010;29(2):154-9.

  3. 3.

    Cruz-Jentoft AJ, Baeyens JP, Bauer JM, et al. Sarcopenia: European consensus on definition and diagnosis: report of the European Working Group on Sarcopenia in older people. Age Ageing. 2010;39(4):412-23.

  4. 4.

    Chen LK, Liu LK, Woo J, et al. Sarcopenia in Asia: consensus report of the Asian Working Group for Sarcopenia. J Am Med Dir Assoc. 2014;15(2):95-101.

  5. 5.

    Studenski SA, Peters KW, Alley DE, et al. The FNIH sarcopenia project: rationale, study description, conference recommendations, and final estimates. J Gerontol A Biol Sci Med Sci. 2014;69(5):547-58.

  6. 6.

    Fielding RA, Vellas B, Evans WJ, et al. Sarcopenia: an undiagnosed condition in older adults. Current consensus definition: prevalence, etiology, and consequences. International working group on sarcopenia. J Am Med Dir Assoc. 2011;12(4):249-56.

  7. 7.

    Morley JE, Abbatecola AM, Argiles JM, et al. Sarcopenia with limited mobility: an international consensus. J Am Med Dir Assoc. 2011;12(6):403-9.

  8. 8.

    Janssen I, Heymsfield SB, Ross R. Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability. J Am Geriatr Soc. 2002;50(5):889-96.

  9. 9.

    Cruz-Jentoft AJ, Bahat G, Bauer J, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing. 2019;48(1):16-31.

  10. 10.

    Chen LK, Woo J, Assantachai P, et al. Asian Working Group for Sarcopenia: 2019 consensus update on sarcopenia diagnosis and treatment. J Am Med Dir Assoc. 2020;21(3):300-7.e2.

  11. 11.

    Bhasin S, Travison TG, Manini TM, et al. Sarcopenia definition: the position statements of the sarcopenia definition and outcomes consortium. J Am Geriatr Soc. 2020;68(7):1410-8.

  12. 12.

    Mohd Nawi SN, Khow KS, Lim WS, et al. Screening tools for sarcopenia in community-dwellers: a scoping review. Ann Acad Med Singap. 2019;48(7):201-16.

  13. 13.

    Mijnarends DM, Meijers JMM, Halfens RJG, et al. Validity and reliability of tools to measure muscle mass, strength, and physical performance in community-dwelling older people: a systematic review. J Am Med Dir Assoc. 2013;14(3):170-8.

  14. 14.

    McGovern J, Dolan RD, Horgan PG, et al. Computed tomography-defined low skeletal muscle index and density in cancer patients: observations from a systematic review. J Cachexia Sarcopenia Muscle. 2021;12(6):1408-17.

  15. 15.

    Hanna L, Nguo K, Furness K, et al. Association between skeletal muscle mass and quality of life in adults with cancer: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2022;13(2):839-57.

  16. 16.

    Nishimura JM, Ansari AZ, D’Souza DM, et al. Computed tomography-assessed skeletal muscle mass as a predictor of outcomes in lung cancer surgery. Ann Thorac Surg. 2019;108(5):1555-64.

  17. 17.

    Amini B, Boyle SP, Boutin RD, et al. Approaches to assessment of muscle mass and myosteatosis on computed tomography: a systematic review. J Gerontol A Biol Sci Med Sci. 2019;74(10):1671-8.

  18. 18.

    Vangelov B, Bauer J, Kotevski D, et al. The use of alternate vertebral levels to L3 in computed tomography scans for skeletal muscle mass evaluation and sarcopenia assessment in patients with cancer: a systematic review. Br J Nutr. 2022;127(5):722-35.

  19. 19.

    Chianca V, Albano D, Messina C, et al. Sarcopenia: imaging assessment and clinical application. Abdom Radiol (NY). 2022;47(9):3205-16.

  20. 20.

    Buckinx F, Landi F, Cesari M, et al. Pitfalls in the measurement of muscle mass: a need for a reference standard. J Cachexia Sarcopenia Muscle. 2018;9(2):269-78.

  21. 21.

    Perkisas S, Bastijns S, Baudry S, et al. Application of ultrasound for muscle assessment in sarcopenia: 2020 SARCUS update. Eur Geriatr Med. 2021;12(1):45-59.

  22. 22.

    Takai Y, Ohta M, Akagi R, et al. Applicability of ultrasound muscle thickness measurements for predicting fat-free mass in elderly population. J Nutr Health Aging. 2014;18(6):579-85.

  23. 23.

    Abe T, Fujita E, Thiebaud RS, et al. Ultrasound-derived forearm muscle thickness is a powerful predictor for estimating DXA-derived appendicular lean mass in Japanese older adults. Ultrasound Med Biol. 2016;42(9):2341-4.

  24. 24.

    Abe T, Loenneke JP, Young KC, et al. Validity of ultrasound prediction equations for total and regional muscularity in middle-aged and older men and women. Ultrasound Med Biol. 2015;41(2):557-64.

  25. 25.

    Sanada K, Kearns CF, Midorikawa T, et al. Prediction and validation of total and regional skeletal muscle mass by ultrasound in Japanese adults. Eur J Appl Physiol. 2006;96(1):24-31.

  26. 26.

    Casey P, Alasmar M, McLaughlin J, et al. The current use of ultrasound to measure skeletal muscle and its ability to predict clinical outcomes: a systematic review. J Cachexia Sarcopenia Muscle. 2022;13(5):2298-309.

  27. 27.

    Zhao R, Li X, Jiang Y, et al. Evaluation of appendicular muscle mass in sarcopenia in older adults using ultrasonography: a systematic review and meta-analysis. Gerontology. 2022;68(10):1174-98.

  28. 28.

    Khalil SF, Mohktar MS, Ibrahim F. The theory and fundamentals of bioimpedance analysis in clinical status monitoring and diagnosis of diseases. Sensors (Basel). 2014;14(6):10895-928.

  29. 29.

    Beaudart C, Bruyère O, Geerinck A, et al. Equation models developed with bioelectric impedance analysis tools to assess muscle mass: a systematic review. Clin Nutr ESPEN. 2020;35:47-62.

  30. 30.

    Wu H, Ding P, Wu J, et al. Phase angle derived from bioelectrical impedance analysis as a marker for predicting sarcopenia. Front Nutr. 2022;9:1060224.

  31. 31.

    Yamada M, Kimura Y, Ishiyama D, et al. Phase angle is a useful indicator for muscle function in older adults. J Nutr Health Aging. 2019;23(3):251-5.

  32. 32.

    McCarthy C, Schoeller D, Brown JC, et al. D3 -creatine dilution for skeletal muscle mass measurement: historical development and current status. J Cachexia Sarcopenia Muscle. 2022;13(6):2595-607.

  33. 33.

    Evans WJ, Hellerstein M, Orwoll E, et al. D3 -Creatine dilution and the importance of accuracy in the assessment of skeletal muscle mass. J Cachexia Sarcopenia Muscle. 2019;10(1):14-21.

  34. 34.

    Cawthon PM, Blackwell T, Cummings SR, et al. Muscle mass assessed by the D3-creatine dilution method and incident self-reported disability and mortality in a prospective observational study of community-dwelling older men. J Gerontol A Biol Sci Med Sci. 2021;76(1):123-30.

  35. 35.

    Cawthon PM, Orwoll ES, Peters KE, et al. Strong relation between muscle mass determined by D3-creatine dilution, physical performance, and incidence of falls and mobility limitations in a prospective cohort of older men. J Gerontol A Biol Sci Med Sci. 2019;74(6):844-52.

  36. 36.

    Orwoll ES, Peters KE, Hellerstein M, et al. The importance of muscle versus fat mass in sarcopenic obesity: a re-evaluation using D3-creatine muscle mass versus DXA lean mass measurements. J Gerontol A Biol Sci Med Sci. 2020;75(7):1362-8.

  37. 37.

    Duchowny KA, Peters KE, Cummings SR, et al. Association of change in muscle mass assessed by D3 -creatine dilution with changes in grip strength and walking speed. J Cachexia Sarcopenia Muscle. 2020;11(1):55-61.

  38. 38.

    Cawthon PM, Manini T, Patel SM, et al. Putative cut-points in sarcopenia components and incident adverse health outcomes: an SDOC analysis. J Am Geriatr Soc. 2020;68(7):1429-37.

  39. 39.

    Otsuka R, Matsui Y, Tange C, et al. What is the best adjustment of appendicular lean mass for predicting mortality or disability among Japanese community dwellers? BMC Geriatr. 2018;18(1):8.

  40. 40.

    Chien KY, Chen CN, Chen SC, et al. A community-based approach to lean body mass and appendicular skeletal muscle mass prediction using body circumferences in community-dwelling elderly in Taiwan. Asia Pac J Clin Nutr. 2020;29(1):94-100.

  41. 41.

    Baumgartner RN, Koehler KM, Gallagher D, et al. Epidemiology of sarcopenia among the elderly in New Mexico. Am J Epidemiol. 1998;147(8):755-63.

  42. 42.

    Furushima T, Miyachi M, Iemitsu M, et al. Comparison between clinical significance of height-adjusted and weight-adjusted appendicular skeletal muscle mass. J Physiol Anthropol. 2017;36(1):15.

  43. 43.

    Seino S, Kitamura A, Abe T, et al. Dose-response relationships between body composition indices and all-cause mortality in older Japanese adults. J Am Med Dir Assoc. 2020;21(6):726-33.e4.

  44. 44.

    Newman AB, Kupelian V, Visser M, et al. Sarcopenia: alternative definitions and associations with lower extremity function. J Am Geriatr Soc. 2003;51(11):1602-9.

  45. 45.

    Delmonico MJ, Harris TB, Lee JS, et al. Alternative definitions of sarcopenia, lower extremity performance, and functional impairment with aging in older men and women. J Am Geriatr Soc. 2007;55(5):769-74.

  46. 46.

    Cawthon PM, Peters KW, Shardell MD, et al. Cutpoints for low appendicular lean mass that identify older adults with clinically significant weakness. J Gerontol A Biol Sci Med Sci. 2014;69(5):567-75.