Metabolomics:Open Access

Polyamines have been implicated in a number of age-related phenotypes. The relationship between polyamines and lean body mass has been less explored. Moreover, the relative influence of amino acids and polyamines on skeletal muscle mass is unknown. Therefore, the purpose of the present study was to investigate circulating amino acid and polyamine patterns and determine their relative influence on skeletal muscle mass. Subjects consisted of 10 females and 53 males. Targeted metabolomics analysis was performed using the AbsoluteIDQ™ p180 kit combined with liquid chromatography tandem mass spectrometry. Analysis of lean body mass index (LBI), lean body mass divided by height squared, found that males had a higher LBI than females (P<0.01) and LBI decreased with advancing age (P<0.05). Using forward stepwise linear regression, only spermidine was related to LBI independent of age and gender. For circulating amino acids, only tyrosine (Tyr) was associated with LBI independently of age and gender. When circulating Tyr was combined with spermidine in the regression