Sarcopenic obesity prevalence is 28% in adults with advanced knee OA and severe obesity

OBJECTIVE: Individuals with advanced knee osteoarthritis (OA) and a larger body size are at risk for sarcopenic obesity (SO), an unfavourable condition of high fat and low muscle mass and function that markedly impacts mobility and morbidity. We examined the prevalence and implications of SO in adults with knee OA and a BMI ≥35 kg/m, comparing various established diagnostic criteria. METHODS: We conducted a cross-sectional analysis of participants at baseline from the POMELO [Prevention of MusclE Loss in Osteoarthritis] pilot randomized clinical trial. The diagnosis of SO was based on published criteria, identifying the co-presence of low muscle function, low muscle mass, and high fat mass. Assessments included maximal handgrip strength (absolute and relative to body size), chair sit-to-stands, muscle [appendicular lean soft tissue] and fat mass measured by DXA, health-related quality of life by Euroqol EQ-5D, and physical function by 6-min walk (6MWT) and Western Ontario and McMaster Osteoarthritis Index (WOMAC). RESULTS: Out of 50 adults (74 % female, 63.7 ± 6.9 years, BMI 42.1 ± 4.6 kg/m), 28 % had criteria for SO (95%CI 15.5-40.4). Individuals with SO had shorter 6MWT distance, -78.6 m (p = 0.012), worse WOMAC function score, 7.2 (p = 0.046), and lower EQ-5D visual analog score, -14.7 (p = 0.016), compared to those without SO. CONCLUSION: SO was present in 28 % (95%CI 15.5-40.4) of our sample with knee OA, with clinically unfavourable implications on measured and self-reported physical function and quality of life. Identification of SO may better stratify patients and enable personalized support to preserve muscle mass and function prior to weight loss or arthroplasty considerations.