Association between sarcopenic obesity and knee osteoarthritis: A narrative review

Sarcopenia and obesity have been studied independently as risk factors for knee osteoarthritis. However, there is now research interest in investigating whether the co-existence of sarcopenia and obesity (sarcopenic obesity) within the same individual significantly increases the risk of knee osteoarthritis, compared to sarcopenia or obesity alone. This review synthesises current literature to explore the association between sarcopenic obesity and knee osteoarthritis, emphasising both the clinical evidence and existing gaps. We highlight the challenges and progress in defining sarcopenic obesity and discuss the impact that the lack of a consensus definition of sarcopenic obesity has on comparing outcomes of studies investigating the relationship between sarcopenic obesity and knee OA. We offer methodological insights to guide future studies investigating whether sarcopenic obesity increases the risk of knee osteoarthritis above and beyond the risk associated with each condition on its own. The implications for clinical practice are discussed, including the need to incorporate effective resistance exercise into weight loss programs for individuals with sarcopenic obesity. This is critical as a general weight loss program alone among individuals with sarcopenic obesity can include substantial loss of muscle mass, potentially predisposing patients to further functional decline.