7 Lifestyle habits have a major impact on sarcopenia as well. These factors include impaired nutrition, reduced physical activity, alcohol consumption, and cigarette smoking.7–9 A scheme of the effects of these lifestyle factors on skeletal muscle and the progression of sarcopenia is presented (Figure 1). Genetic factors may also affect the progression of sarcopenia. Muscle mass and strength are multifactorial traits that vary widely among individuals. Inhibitors,research,lifescience,medical The genetic component of sarcopenia is complex and driven by many genes. Several genes have been identified that
contribute to variation of skeletal muscle mass and strength, including the IGF-1 and vitamin D receptor genes.10 Since lifestyle factors are more controllable in comparison with age-related systemic changes and genetic Inhibitors,research,lifescience,medical factors, it is of great importance to raise the public awareness regarding their
influence on the progression of sarcopenia. This review aims to Inhibitors,research,lifescience,medical present the importance of lifestyle factors as causes of sarcopenia and potential strategies for prevention and treatment of sarcopenia. Figure 1 Lifestyle factors affecting sarcopenia. DIETARY FACTORS IN SARCOPENIA Aging is associated with reduced appetite and low food intake, which was previously termed the “anorexia of ageing.”11 Several causes have been suggested to explain this phenomenon. Anorexia of aging may be the result of early satiety owing to decreased relaxation of the fundus, increased release of cholecystokinin, and increased leptin levels.6,11 Altered taste and smell, social changes, and economic Inhibitors,research,lifescience,medical limitations may also lead to decreased food intake.12 These may result in low nutrient intake, which is an important risk factor in the development of sarcopenia. In particular, protein intake has a major influence on skeletal muscle metabolism. Inadequate protein intake is one of the major mechanisms Inhibitors,research,lifescience,medical underlying sarcopenia. The current recommended dietary
allowance (RDA) of protein is Dipeptidyl peptidase 0.8 g/kg/day.3 It has been estimated that approximately 40% of people over the age of 70 do not meet this RDA.3 Furthermore, ERK inhibitor mw nitrogen balance studies in aging populations have indicated greater protein needs for the elderly (1.14 g/kg/day) relative to the young (0.8 g/kg/day).13 Thalacker-Mercer et al.14 assessed the effect of 1 week of inadequate protein intake (0.5 g/kg/day) compared with adequate protein intake (1.2 g/kg/day) on gene expression profiles in skeletal muscle of older adults. It was shown that inadequate protein intake is associated with down-regulation of transcripts associated with protein synthesis, myosin formation, and proliferation of satellite cells.