Sarcopenia: revised European consensus on definition and diagnosis

This is the 2019 EWGSOP2 (European Working Group on Sarcopenia in Older People, second iteration) consensus statement — the framework that recast sarcopenia diagnosis and that anchors the contemporary sarcopenia-trial literature in Europe and increasingly globally. The document is a Tier 2 source in the corpus's framework: a peer-reviewed consensus guideline rather than a primary trial, but the rate-limiting reference for how sarcopenia is operationally defined and therefore for how every sarcopenia-relevant peptide trial is interpreted.

The structural innovation of EWGSOP2 is the demotion of muscle mass from the primary diagnostic criterion. The original EWGSOP 2010 framework treated low muscle mass as the entry criterion, with strength and function as confirmatory. EWGSOP2 reverses that order: low muscle strength becomes the primary diagnostic indicator, low muscle quantity or quality becomes the confirmatory finding, and poor physical performance becomes the severity grade. The reasoning is empirical — across longitudinal cohorts, muscle strength predicts the outcomes that make sarcopenia a clinical priority (falls, fractures, hospitalization, loss of independence, mortality) more reliably than mass alone. Sarcopenia, on the EWGSOP2 framing, is fundamentally a muscle disease defined by what muscle does, not by how much of it there is on a DXA scan.

The operational algorithm is the "Find-Assess-Confirm-Severity" sequence. Case-finding starts with SARC-F (a five-item screening questionnaire) or with clinical suspicion (recent falls, weakness, slow walking, unintentional weight loss). Assessment of strength is by grip dynamometry (cutoffs ≤27 kg in men, ≤16 kg in women) or by the five-times-sit-to-stand test (>15 seconds). Confirmation of low muscle quantity is by DXA-derived appendicular lean mass, bioimpedance analysis in field settings, or CT/MRI in research-grade work. Severity grading uses physical performance measures: gait speed ≤0.8 m/s, Short Physical Performance Battery score ≤8, Timed Up-and-Go ≥20 seconds, or 400-meter walk failure. The algorithm produces three operational categories — probable sarcopenia (low strength only), confirmed sarcopenia (low strength plus low mass/quality), and severe sarcopenia (all three components).

The editorial weight of EWGSOP2 for the sarcopenia-and-peptides dossier rests on what the strength-first reframing implies about the GH-axis and GHSR-1a-agonist peptide literature. Lean-mass gains on MK-677 (Nass et al. 2008, Adunsky et al. 2011) and on anamorelin (Temel et al. 2016) did not translate into strength or function improvements. Under the older mass-first EWGSOP framework, those results would have been read as encouraging — the lean-mass endpoint moved. Under EWGSOP2, the same results are a structural caution: the variable that moved is not the variable that defines the clinical condition. The strength-first reframing turns "mass-without-strength" from a side observation into a frame-defining null. The dossier's recurrent pattern across the GH-secretagogue class is read through this lens.