Association of muscle wasting with mortality risk among adults: A systematic review and meta-analysis of prospective studies.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of prospective cohort studies
PubMed 37209044 · doi:10.1002/jcsm.13263
What was done
A systematic review and meta-analysis of prospective cohort studies searched PubMed, Web of Science, and the Cochrane Library through March 22, 2023. Eligible studies examined associations between low versus normal muscle mass categories and all-cause or cause-specific mortality in general adult populations. Random-effects models calculated pooled relative risks (RRs) and 95% confidence intervals (CIs). Subgroup analyses, meta-regression, and dose-response analyses were performed.
What was found
Across 49 prospective studies comprising 878,349 participants and 61,055 deaths followed for 2.5 to 32 years, muscle wasting was associated with higher mortality risks across multiple outcomes: - All-cause mortality: RR = 1.36 (95% CI, 1.28 to 1.44; I² = 94.9%; 49 studies) - Cardiovascular disease mortality: RR = 1.29 (95% CI, 1.05 to 1.58; I² = 88.1%; 8 studies) - Cancer mortality: RR = 1.14 (95% CI, 1.02 to 1.27; I² = 38.7%; 3 studies) - Respiratory disease mortality: RR = 1.36 (95% CI, 1.11 to 1.67; I² = 62.8%; 3 studies) Subgroup analyses showed muscle wasting predicted all-cause mortality regardless of muscle strength. An approximately inverse linear dose-response relationship was observed between mid-arm muscle circumference and all-cause mortality (P < 0.01 for non-linearity). Meta-regression showed lower risk estimates in studies with longer follow-ups for all-cause (P = 0.06) and cardiovascular (P = 0.09) mortality.
Why it matters
This review establishes that low muscle mass is independently associated with increased risks of all-cause, cardiovascular, cancer, and respiratory mortality in the general population. It supports early detection and preservation of muscle mass to promote longevity.
Limits
Statistical heterogeneity was extremely high for all-cause (I² = 94.9%) and cardiovascular (I² = 88.1%) mortality. Cause-specific analyses for cancer and respiratory disease were based on only 3 studies each. As an observational synthesis, residual confounding and reverse causality cannot be completely excluded.
Cited by
- supports Muscle strength and muscle size serve as predictors of all-cause mortality and disability.