Relationship between muscle mass and muscle strength with physical performance in older adults: A systematic review

BACKGROUND: Declining muscle mass is not always accompanied by declining muscle strength in older adults, challenging the notion that low muscle mass is the sole criterion for diagnosing sarcopenia. OBJECTIVE: This review aims to find out the relationships between muscle mass and muscle strength with physical performance in older adults. DESIGN: This article was a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. DATA SOURCES AND METHODS: We do a systematic search of observational studies that are published between 2013 and August 2023 in PubMed, ScienceDirect, Sage journal, Tripdatabase, Cochrane Library, Embase, and CINAHL. Two reviewers selected and extracted data independently and an association measure was recorded from included studies. RESULTS: The review analyzed 17 observational studies conducted between 2013 and September 2023. The findings suggest that while declining muscle mass is often associated with sarcopenia, it may not always correspond to declining muscle strength in older individuals. The most common method used to measure muscle mass was bioelectrical impedance analysis, while handgrip strength was the predominant measure of muscle strength. Tests such as timed up and go and gait speed were used to assess physical performance. CONCLUSIONS: Physical performance in older adults is significantly related to muscle strength, whereas the relationship between muscle mass and physical performance is either weak or negligible. Therefore, when evaluating physical performance in older individuals, focusing on muscle strength is more important than muscle mass alone.