The effect of a controlled 8-week metabolic ward based lysine supplementation on muscle function, insulin sensitivity and leucine kinetics in young men

摘要

Background & aims: The 2007 FAO/WHO/UNU lysine requirement is 30mgkg-1d-1. Developing country populations may be at risk of lysine deficiency, with effects on muscle and its function. The effect of an 8wk lysine supplementation diet on muscle mass and function was assessed. Methods: Healthy, under and well-nourished men were studied before and after 8wk, during which low (n=20) and high (n=20) lysine diets were consumed. The low lysine diets (～25 and ～40mgkg-1d-1 for under and well-nourished respectively) were based on the subjects' habitual lysine intake, while the high lysine diet supplied 80mgkg-1d-1. Anthropometry, muscle function, insulin sensitivity (IS) and leucine kinetics were measured before and after the experimental period. Results: The high lysine diet had a small positive effect (about +7.5%) on muscle strength, but no effect on other parameters. Over the 8. wk period in the whole group, the change in muscle strength correlated with the change in muscle mass (r=0.5, P=0.001), while the change in muscle mass correlated with the change in IS (r=0.3, P=0.04), but there were no intake specific differences. Conclusion: Over an 8wk controlled feeding period, an intake of 80mglysinekg-1d-1 had a small positive effect on muscle strength, but no other effects.