The implications of sarcopenia and sarcopenic obesity on cardiometabolic disease

The important changes in body composition associated with aging are a decline in skeletal muscle mass and an increase in body fat. Body fat distribution also changes with age; subcutaneous fat decreases and visceral abdominal fat increase, which contributes to numerous cardiometabolic diseases (CMDs) such as type 2 diabetes, dyslipidemia, and cardiovascular disease (CVD). Sarcopenia often accompanied by an increase in body fat and vice versa, a scenario termed sarcopenic obesity (SO), which might lead to the cumulative risk of both sarcopenia and obesity. However, there is still no consensus regarding the definition and consequences of SO. The lack of a unified definition for SO might contribute to inconsistent findings about the association of SO with CMD. Complex etiologies are associated with development of SO. A vicious cycle between the loss of muscle and the accumulation of ectopic fat might be associated with CMD via an intricate interplay of factors including proinflammatory cytokines, oxidative stress, mitochondrial dysfunction, insulin resistance, dietary energy, physical activity, mitochondrial dysfunction, and other factors that have yet to be identified. Moreover, recent epidemiological studies suggest that SO is related to CVD and mortality. This review focuses on the current literature with regard to the association between sarcopenia, dynapenia, and obesity, as well as their implications for CMD. The ultimate goal of this Prospects is to encourage conduct of well-designed future studies that elucidate the relationship among sarcopenia, SO, and CMD.