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

Fig. 1
figure 1

The list of accepted and rejected statements from the Delphi study (n = 107 participants). Sourced from Kirk et al. [1]

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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.

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

Fig. 2
figure 2

The global conceptual definition of Sarcopenia. Sourced from Kirk et al. [1]

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Summary

The global conceptual definition of sarcopenia has been developed using an International Delphi Study including academic, industry and healthcare professionals from leading musculoskeletal organisations and sarcopenia societies. This inclusive approach will serve as a strong backbone 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 including 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.