BODY composition significantly influences the quality of life for patients with knee and hip osteoarthritis, according to a study led by Professor Anne-Christine Rat. Drawing on data from the Knee and Hip OsteoArthritis Long-term Assessments (KHOALA) cohort, researchers explored how fat mass and muscle mass affect physical and mental well-being over a four-year period.
The study analysed 878 patients with symptomatic knee or hip osteoarthritis, using dual X-ray absorptiometry (DXA) scans to measure body composition variables such as fat mass index (FMI), skeletal muscle mass index (SMI), and fat distribution. Findings revealed that higher FMI and low muscle mass were associated with worsening physical function, as assessed by patient-reported outcomes such as the Study Short Form-36 (SF-36) and OsteoArthritis Knee and Hip Quality of Life (OAKHQOL) scales. Conversely, higher trunk-to-leg fat mass ratios and greater skeletal muscle mass were linked to improved mental health and vitality over time.
Interestingly, the study found no significant association between body composition and changes in pain levels. This challenges assumptions that weight-related factors directly influence pain in osteoarthritis patients, instead highlighting the nuanced roles of fat and muscle in overall health outcomes.
Professor Rat noted the importance of these findings for personalising osteoarthritis care. Addressing excess fat and promoting muscle retention could improve both physical functioning and mental well-being in patients with knee or hip osteoarthritis. The research emphasises the need for a holistic approach to body composition management, moving beyond weight loss alone.
These findings underscore the potential for tailored interventions to enhance the quality of life for osteoarthritis patients, offering new insights into the broader impacts of fat and muscle mass on long-term health outcomes.
Aleksandra Zurowska, EMJ
Reference
Rat A et al. Body composition is associated with changes in health-related quality of life in patients with knee and/or hip osteoarthritis. RMD Open. 2025; DOI: 10.1136/rmdopen-2024-004733.
