Sarcopénie des sujets âgés : libérez les acides aminés !

The underlying mechanisms of sarcopenia (i.e. the loss of muscle mass in aging) are still unknown. The primum movens seems to be a blunted anabolic response of muscle to dietary intake which could be related to a decreased systemic availability of amino acids. The latter could be linked to an increased amino acid metabolism in the splanchnic area. This splanchnic sequestration should be saturated by i) an increase in protein intake (global or in specific amino acids), ii) a modification of the rhythm of intake, or iii) the use of “fast” proteins. Alternatively (or in addition), the alteration of protein synthesis with advance in age could be located in the muscle, by decreasing the anabolic stimuli (e.g. insulin, GH, testosterone) or by increasing the catabolic environment (e.g. cortisol, pro-inflammatory cytokines).