Low muscle strength, rather than sarcopenia itself, may be a key driver of falls risk in patients with rheumatoid arthritis, according to a six-year prospective cohort study. The findings suggest that functional measures of muscle strength may offer greater prognostic value than body composition alone in this population.
Sarcopenia Prevalence Remains Stable Over Time
The study followed 90 patients with rheumatoid arthritis for a median of 6.4 years, assessing changes in body composition, muscle strength, physical performance, and clinical outcomes including falls, fractures, and mortality. Sarcopenia was defined using EWGSOP2 criteria and evaluated using dual-energy X-ray absorptiometry, grip strength testing, and physical performance measures.
At baseline, 7.7% of patients met criteria for sarcopenia, including one case of severe sarcopenia. Most participants were overweight with elevated fat mass index. Notably, no new cases of sarcopenia developed during follow-up, and overall prevalence and clinical characteristics remained stable, suggesting that sarcopenia did not substantially progress in this cohort receiving regular rheumatologic care.
Muscle Strength Emerges as a Key Prognostic Factor
Although sarcopenia and low muscle mass were not independently associated with falls, fractures, or mortality, muscle strength told a different story. After adjusting for age, disease duration, glucocorticoid exposure, and disease-modifying antirheumatic drug use, low muscle strength was significantly associated with an increased risk of falls.
Low grip strength was linked to nearly a fourfold increase in falls risk. In addition, low muscle strength showed a trend toward increased mortality risk, although this association did not reach statistical significance, likely due to the limited sample size.
Importantly, neither low appendicular lean mass nor impaired physical performance were associated with adverse outcomes, highlighting the distinct clinical relevance of strength-based assessments.
Implications for Clinical Care in Rheumatoid Arthritis
The findings underscore the importance of routinely assessing muscle strength in patients with rheumatoid arthritis, particularly as a marker of fall risk. While sarcopenia prevalence remained stable over time, muscle weakness appeared to carry independent prognostic value.
The authors note that the absence of a control group limits conclusions regarding disease-specific versus age-related changes. However, the results support incorporating simple strength assessments, such as grip strength testing, into routine rheumatology practice to help identify patients at higher risk of falls and potentially poorer outcomes.
Reference
do Espírito Santo et al. Longitudinal impact of sarcopenia and its components on falls, fractures, and mortality in rheumatoid arthritis: a six-year study. BMC Rheumatol. 2025;DOI: 10.1186/s41927-025-00593-w.
