Obesity in the sarcopenia era

摘要

WITH the coining of the term "sarcopenia," lean body mass has been a major focus of aging research for the past 25 years. The motivating idea is that weakness, a hallmark of physical disability, is determined by skeletal muscle mass. Therefore, a logical strategy to prevent disability would be to slow or reverse age-related decreases in muscle mass (1). However, evidence shows that the situation is more nuanced than originally expected. In community-dwelling older adults, the linkage between lean mass and strength is not especially strong, and some interventions that are effective in increasing lean mass do not appear to affect strength (2,3). Furthermore, intentional weight loss in obese older adults does not necessarily reduce muscle strength, despite significant reductions in muscle mass (4).