Sarcopenia and mortality in different clinical conditions: A meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of cohort studies
PubMed 33997305 · doi:10.1016/j.afos.2021.02.001
What was done
A systematic search of PubMed, Cochrane Library, and Embase was conducted for cohort studies published before December 20, 2017, examining the association between lean mass and all-cause mortality. Included studies measured lean mass using dual-energy X-ray absorptiometry (DXA), bioimpedance analysis (BIA), or computed tomography (CT) as continuous (per standard deviation decrease) or binary variables (sarcopenia cutoffs). Studies using muscle surrogates, anthropometrics, rate of change, or composite diagnostic criteria were excluded. Pooled hazard ratios (HR) were calculated using a random-effects model.
What was found
A total of 188 studies with 98,468 participants from 34 countries were included. Across the 68 studies in the quantitative meta-analysis, the pooled HR for mortality was 1.36 for every standard deviation decrease in lean mass and 1.74 for low lean mass defined by cutoffs. Significant associations were reported in elderly populations and across all disease subgroups and measurement modalities. The abstract did not report confidence intervals or exact p-values.
Why it matters
This review establishes a consistent association between low lean mass and increased all-cause mortality across diverse clinical conditions, demonstrating that lean mass measurement has broad prognostic relevance.
Limits
All included data derive from observational cohort studies, preventing causal inference and leaving open confounding by disease severity or malnutrition. The analysis excluded composite sarcopenia definitions that incorporate muscle strength or physical performance. Search results were limited to publications up to 2017, and confidence intervals or heterogeneity statistics are omitted from the abstract.
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