Sarcopenic obesity as a determinant of cardiovascular disease risk in older people: a systematic review

BACKGROUND: Aging is associated with body composition changes that include a reduction of muscle mass or sarcopenia and an increase in visceral obesity. Thus, aging involves a muscle-fat imbalance with a shift toward more fat and less muscle. Therefore, sarcopenic obesity, defined as a combination of sarcopenia and obesity, is a global health phenomenon due to the increased aging of the population combined with the increased epidemic of obesity. Previous studies have shown inconsistent association between sarcopenic obesity and the risk of cardiovascular disease (CVD). AIMS: To systematically review the recent literature on the CVD risks associated with sarcopenic obesity and summarizes ways of diagnosis and prevention. METHODS: A systematic review of studies that reported the association between sarcopenic obesity and CVD risk in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. RESULTS: Risk factors of sarcopenic obesity included genetic factors, aging, malnutrition, sedentary lifestyle, hormonal deficiencies and other molecular changes. The muscle-fat imbalance with increasing age results in an increase in the pro-inflammatory adipokines secreted by adipocytes and a decline in the anti-inflammatory myokines secreted by myocytes. This imbalance promotes and perpetuates a chronic low-grade inflammatory state that is characteristic of sarcopenic obesity. After application of exclusion criteria, only 12 recent studies were included in this review. The recent studies have shown a consistent association between sarcopenic obesity and cardiovascular disease risk although most of the studies are of cross-sectional design that does not confirm a causal relationship. In addition, most of the population studied were of Asian origin which may limit the generalizability of the results. Non-pharmacological interventions by exercise training and adequate nutrition appear to be useful in maintenance of muscle strength and muscle mass in combination with a reduction of adiposity to promote healthy aging. CONCLUSIONS: Sarcopenic obesity appears to increase the risk of CVD in older people; however, future prospective studies of diverse population are still required. Although non-pharmacologic interventions are useful in reducing the risk of sarcopenic obesity, novel specific pharmacologic agents are lacking.