Current sarcopenia definitions and clinical outcomes: a need for homogeneity?

Article: Predictive validity of current sarcopenia definitions (EWGSOP2, SDOC, and AWGS2) for clinical outcomes: A scoping review

Three new definitions of sarcopenia have emerged in the past four years, proposed by the Sarcopenia Definition and Outcome Consortium (2020, SDOC), the European Working Group on Sarcopenia in Older People (2019, EWGSOP2) and the Asian Working Group on Sarcopenia (2019, AWGS2). No consensus on a unique definition of sarcopenia has yet been achieved, as the three new definitions proposed exhibit significant differences from each other. EWGSOP2’s definition of sarcopenia, for instance, characterises it as low muscle strength and mass, while the one developed by SDOC focuses on low muscle strength and gait speed instead.

The aim of this scoping review was to investigate all three recent sarcopenia definitions’ predictive validity for clinical outcomes.

Key learnings:

Significant heterogeneity was found between definitions of clinical outcomes used to test the predictive ability of EWGSOP2, SDOC, and AWGS2, with a substantial proportion of validity tests assessing the definitions’ predictive validity on general health outcomes instead of sarcopenia-specific ones. This greatly impaired the study’s ability to analyse each definition’s predictive value. It is thus critical to achieve consensus on an operational definition of clinical outcomes relevant to sarcopenia. Furthermore, future studies should focus on including both men and women to effectively compare current sarcopenia definitions’ predictive validity for defined key clinical outcomes.

Reviewed by: S. Duarte

Authors: Stuck AK, Basile G, Freystaetter G et al.

Published in: JCSM 2022