# An executive summary on the Global conceptual definition of Sarcopenia

Ben Kirk, Peggy M Cawthon, Hidenori Arai, Jose Alberto Avila-Funes, Rocco Barazzoni, Shalender Bhasin, Ellen F Binder, Olivier Bruyère, Tommy Cederholm, Liang-Kung Chen, et al.

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Ben Kirk, Peggy M Cawthon, Hidenori Arai, Jose Alberto Avila-Funes, Rocco Barazzoni, et al. An executive summary on the Global conceptual definition of Sarcopenia. Aging Clinical and Experimental Research, 2024, 36 (1), pp.153. 10.1007/s40520-024-02798-4. hal-04701390

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# An executive summary on the Global conceptual definition of Sarcopenia

Ben Kirk<sup>1,2</sup> · Peggy M. Cawthon<sup>3,4</sup> · Hidenori Arai<sup>5</sup> · José A. Ávila-Funes<sup>6,7</sup> · Rocco Barazzoni<sup>8</sup> · Shalender Bhasin<sup>9</sup> · Ellen F. Binder<sup>10</sup> · Olivier Bruyère<sup>11,12</sup> · Tommy Cederholm<sup>13,14</sup> · Liang-Kung Chen<sup>15,16</sup> · Cyrus Cooper<sup>17,18</sup> · Gustavo Duque<sup>19,20</sup> · Roger A. Fielding<sup>21</sup> · Jack Guralnik<sup>22</sup> · Douglas P. Kiel<sup>23</sup> · Francesco Landi<sup>24</sup> · Jean-Yves Reginster<sup>25,26</sup> · Avan A. Sayer<sup>27</sup> · Marjolein Visser<sup>28,29</sup> · Stephan von Haehling<sup>30,31</sup> · Jean Woo<sup>32</sup> · Alfonso J. Cruz-Jentoft<sup>33</sup> · The Global Leadership Initiative in Sarcopenia (GLIS) Group

Received: 7 June 2024 / Accepted: 23 June 2024
© The Author(s) 2024

**Keywords** Sarcopenia · Muscle mass · Muscle strength

## Objective

To address a significant gap in research and clinical practice by developing the global conceptual definition of Sarcopenia.

## Methodology

### Study design

Two-phase Delphi study with participants from leading international musculoskeletal organisations and sarcopenia societies [1]. A steering committee was formed of representatives from each continent/region (Asia, Europe, North America, South America, New Zealand/Australia). The steering committee then developed a glossary of research terms on sarcopenia [2]. Following this, a list of statements on critical aspects of sarcopenia was developed and finalised.

### Participants

Invitations to complete an online survey were sent to international experts from academic, industry, and healthcare professions. All participants including steering committee members completed a declaration of interest form prior to participation.

## Statistical analysis

Prespecified criteria were set by the steering committee including a two-phase study design and an acceptable threshold of > 80% for accepted statements [1].

## Findings

### Participants

107 participants (64% men) from 29 countries and across 7 continents/regions completed the Delphi. The majority were residing in Europe (40%), Asia (22%) and North America (19%). Participants reported their primary role as academic professionals (76 [71%]), health professional (23 [22%], industry professionals (3 [2%]), or other-mixed (5 [5%]).

## Accepted and rejected statements

Across the three facets of sarcopenia; ‘general aspects’, ‘components’ and ‘outcomes’, 20 statements were accepted with strong agreement and 4 rejected with low agreement. Figure 1 shows the list of accepted and rejected statements

## Key points

### General aspects

Sarcopenia is a disease of skeletal muscle; the definition will be the same for research and clinical practice; the definition will not depend on age, setting of care or clinical condition.

<footnote>The list of societies and organisations taking part in the GLIS initiative are mentioned in Acknowledgements.</footnote>

<footnote>Extended author information available on the last page of the article</footnote>
<table><caption>**Fig. 1** The list of accepted and rejected statements from the Delphi study (n = 107 participants). Sourced from Kirk et al. [1]</caption><thead><tr><th></th><th>Agreement (mean ± SD)</th><th>Agreement (%)</th><th>Outcome</th></tr></thead><tbody><tr><td colspan="4"><strong>Statements from round 1</strong></td></tr><tr><td>Sarcopenia is a generalised disease of skeletal muscle</td><td>8.1 ± 2.3</td><td>85.4%</td><td>Accepted</td></tr><tr><td>The prevalence of sarcopenia increases with age</td><td>9.7 ± 0.6</td><td>98.3%</td><td>Accepted</td></tr><tr><td>The conceptual definition of sarcopenia should not vary by setting of care (e.g., inpatient vs. outpatient)</td><td>8.8 ± 1.7</td><td>91.2%</td><td>Accepted</td></tr><tr><td>The conceptual definition of sarcopenia should not vary by age or condition (e.g., heart failure, kidney disease, cancer etc.)</td><td>7.8 ± 2.7</td><td>83.2%</td><td>Accepted</td></tr><tr><td>The conceptual definition of sarcopenia should be the same for clinical practice and research</td><td>8.9 ± 1.6</td><td>92.0%</td><td>Accepted</td></tr><tr><td>Muscle mass should be part of the conceptual definition of sarcopenia</td><td>8.5 ± 2.0</td><td>89.4%</td><td>Accepted</td></tr><tr><td>Morphological characteristics of muscle tissue (e.g., muscle fat infiltration, muscle density or texture) should be part of the conceptual definition of sarcopenia</td><td>6.2 ± 2.8</td><td>69.9%</td><td>Rejected</td></tr><tr><td>Muscle strength should be a part of the conceptual definition of sarcopenia</td><td>9.1 ± 1.9</td><td>93.1%</td><td>Accepted</td></tr><tr><td>Muscle power should be part of the conceptual definition of sarcopenia</td><td>6.1 ± 2.5</td><td>68.4%</td><td>Rejected</td></tr><tr><td>Sarcopenia increases the risk of impaired physical performance</td><td>9.6 ± 0.8</td><td>97.9%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of mobility (walking) limitations</td><td>9.4 ± 1.1</td><td>96.1%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of mobility (transfer from chair or bed to rising) limitations</td><td>9.3 ± 1.1</td><td>95.0%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of falls</td><td>9.2 ± 1.2</td><td>94.6%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of fractures</td><td>8.5 ± 1.7</td><td>89.4%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of inability to perform instrumental ADLs</td><td>8.6 ± 1.8</td><td>88.6%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of inability to perform basic (self-care) ADLs</td><td>8.8 ± 1.7</td><td>90.7%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of hospitalizations</td><td>8.7 ± 1.4</td><td>91.0%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of new admission to care (nursing) homes</td><td>8.6 ± 1.7</td><td>89.5%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of poor quality of life</td><td>8.9 ± 1.5</td><td>91.8%</td><td>Accepted</td></tr><tr><td>Sarcopenia increases the risk of mortality</td><td>8.9 ± 1.4</td><td>91.6%</td><td>Accepted</td></tr><tr><td colspan="4"><strong>Statements from round 2</strong></td></tr><tr><td>Muscle specific strength (e.g., muscle strength/muscle size) should be part of the conceptual definition of sarcopenia</td><td>7.5 ± 2.7</td><td>80.8%</td><td>Accepted</td></tr><tr><td>Physical performance should be part of the conceptual definition of sarcopenia</td><td>7.5 ± 2.6</td><td>79.8%</td><td>Rejected</td></tr><tr><td>The conceptual definition of sarcopenia should be a potentially reversible disease</td><td>7.9 ± 2.3</td><td>84.1%</td><td>Accepted</td></tr><tr><td>The conceptual definition of sarcopenia should include levels of severity of the disease</td><td>7.1 ± 2.7</td><td>77.0%</td><td>Rejected</td></tr><tr><td colspan="4"><strong>N.B. An 11-point Likert scale ranging from strongly disagree (0) to strongly agree (10) accompanied each statement</strong></td></tr><tr><td colspan="4"><table><thead><tr><th></th><th>Weighted-scales calculation</th><th></th></tr><tr><th></th><th>Response</th><th>Weight</th><th>Interpretation</th></tr></thead><tbody><tr><td>Statements with strong agreement (&gt;80% respondents scoring ≥7) accepted</td><td>9, 10</td><td>100%</td><td>Strongly agree</td></tr><tr><td>Statements with low agreement (&lt;70% respondents scoring ≥7) rejected</td><td>7, 8</td><td>80%</td><td>Agree<br>Neither agree<br>nor disagree</td></tr><tr><td></td><td>4, 5, 6</td><td>60%</td><td>Disagree</td></tr><tr><td></td><td>2, 3</td><td>40%</td><td>Strongly disagree</td></tr><tr><td></td><td>0, 1</td><td>20%</td><td>Strongly disagree</td></tr></tbody></table></td></tr></tbody></table>

## Components

The definition will comprise of both reduced muscle mass and strength, as well as muscle-specific strength. Physical performance will not be considered as a component of sarcopenia but instead as an outcome.

## Outcomes

Sarcopenia increases a host of adverse health outcomes (e.g. fragility fractures, disability, poor quality of life), nursing home admissions and premature mortality. Impaired

physical performance will be considered a measurable outcome of sarcopenia.

Figure 2 shows the global conceptual definition of sarcopenia that will be used to develop an operationalized definition

## Summary

The global conceptual definition of sarcopenia has been developed using an International Delphi Study including academic, industry and healthcare professionals from

<figure><img src="image_2.png" /><figcaption>**Fig. 2** The global conceptual definition of Sarcopenia. Sourced from Kirk et al. [1]</figcaption></figure>
leading musculoskeletal organisations and sarcopenia soci-
eties. This inclusive approach will serve as a strong back-
bone to develop an operational definition of sarcopenia for
research and clinical settings.

Future directions

Three working groups are currently underway to develop an
operational definition of sarcopenia. These working groups,
comprising of experts on specific sarcopenia topics includ-
ing components and outcomes of the disease, are expected
to finalise the operational definition in the coming year(s).

The Global Leadership Initiative in Sarcopenia (GLIS)
represents a significant advancement in the field to improve
the prevention, diagnosis and treatment of this muscle
disease.

**Acknowledgements** The list of societies and organisations taking part in the GLIS initiative Aging in Motion (AIM) coalition/Alliance for Aging Research (AAR). American Geriatrics Society (AGS). American Society for Bone and Mineral Research (ASBMR). Asian Association for Frailty and Sarcopenia (AAFS). Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR). European Association for the Study of Obesity (EASO). European Geriatric Medicine Society (EuGMS). European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO). European Society for Clinical Nutrition and Metabolism (ESPEN)/ Global Leadership Initiative on Malnutrition (GLIM). Gerontological Society of America (GSA). International Association of Gerontology and Geriatrics (IAGG). International Conference on Frailty and Sarcopenia Research (ICFSR). International Osteoporosis Foundation (IOF). Society on Sarcopenia, Cachexia and Wasting Disorders (SCWD).

**Author contributions** All authors contributed to the original manuscript

**Data Availability** No datasets were generated or analysed during the current study.

Declarations

**Conflict of interest** All authors declarations of conflicts of interests and declarations of sources of funding can be read here: https://www.eugms.org/fileadmin/images/news/2022/GLIS_Steering_Committee_Rev3.pdf

**Open Access** This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

References

1. Kirk B, Cawthon PM, Arai H et al (2024) The conceptual definition of sarcopenia: Delphi consensus from the global leadership initiative in sarcopenia (GLIS). Age Ageing. https://doi.org/10.1093/ageing/afae052

2. Cawthon PM, Visser M, Arai H et al (2022) Defining terms commonly used in sarcopenia research: a glossary proposed by the global leadership in sarcopenia (GLIS) steering committee. Eur Geriatr Med 13:1239–1244. https://doi.org/10.1007/S41999-022-00706-5

**Publisher's Note** Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Authors and Affiliations

Ben Kirk¹,² · Peggy M. Cawthon³,⁴ · Hidenori Arai⁵ · José A. Ávila-Funes⁶,⁷ · Rocco Barazzoni⁸ · Shalender Bhasin⁹ · Ellen F. Binder¹⁰ · Olivier Bruyère¹¹,¹² · Tommy Cederholm¹³,¹⁴ · Liang-Kung Chen¹⁵,¹⁶ · Cyrus Cooper¹⁷,¹⁸ · Gustavo Duque¹⁹,²⁰ · Roger A. Fielding²¹ · Jack Guralnik²² · Douglas P. Kiel²³ · Francesco Landi²⁴ · Jean-Yves Reginster²⁵,²⁶ · Avan A. Sayer²⁷ · Marjolein Visser²⁸,²⁹ · Stephan von Haehling³⁰,³¹ · Jean Woo³² · Alfonso J. Cruz-Jentoft³³ · The Global Leadership Initiative in Sarcopenia (GLIS) Group

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Alfonso J. Cruz-Jentoft
alfonsojose.cruz@salud.madrid.org

¹ Department of Medicine, Western Health, Melbourne Medical School, University of Melbourne, St Albans, Melbourne, VIC, Australia

² Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St Albans, Melbourne, VIC, Australia

³ California Pacific Medical Center, Research Institute, 550 16th Street, Second Floor, San Francisco, CA 94143, USA

⁴ Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA

5 National Center for Geriatrics and Gerontology, Obu, Aichi, Japan

⁶ Department of Geriatrics, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico, Mexico

7 Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, UMR 1219, 33000 Bordeaux, France

8 Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
9 Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA

10 Division of General Medicine and Geriatrics, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA

11 WHO Collaborating Center for Public Health Aspects of Musculo-Skeletal Health and Ageing, Division of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium

12 Department of Sport and Rehabilitation Sciences, University of Liège, Liège, Belgium

13 Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden

14 Theme Inflammation and Ageing, Karolinska University Hospital, Stockholm, Sweden

15 Center for Geriatrics and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan

16 Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan

17 MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK

18 Department of Epidemiology, University of Oxford, Oxford, OX, UK

19 Bone, Muscle and Geroscience Group, Research Institute of the McGill University Health Centre, Montreal, QC, Canada

20 Dr. Joseph Kaufmann Chair in Geriatric Medicine, Department of Medicine, McGill University, Montreal, QC, Canada

21 Nutrition Exercise, Physiology, and Sarcopenia Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition

Research Center On Aging, Tufts University, Boston, MA, USA

22 Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA

23 Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Department of Medicine Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA

24 Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, 00168 Rome, Italy

25 WHO Collaborating Center for Epidemiology of Musculoskeletal Health and Aging, Liège, Belgium

26 Chair for Biomarkers of Chronic Diseases, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

27 AGE Research Group, NIHR Newcastle Biomedical Research Centre, Newcastle Hospitals and Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK

28 Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands

29 The Amsterdam Public Health Research Institute, Amsterdam, The Netherlands

30 Department of Cardiology and Pneumology, University Medicine Göttingen (UMG), Göttingen, Germany

31 German Centre for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany

32 Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China

33 Servicio de Geriatría, Hospital Universitario Ramón y Cajal (IRYCIS), Madrid, Spain