Higher sirt1 is associated with a better body composition in master sprinters and untrained peers.

Sirt1 is an enzyme involved in several anti-aging pathways. Associations between Sirt1, age, and body fat (BF) were assessed in master sprinters (MS; n = 35; 50.25 ±5.93 yr.), untrained young non-athletes (UY; n = 32; 23.78 ±3.98 yr.), and untrained middle-aged (UMA; n = 24; 47.29 ±8.04 yr.). BF was assessed using a skinfold protocol, and Sirt1 was measured in plasma by using commercial kits. Sirt1 of MS (17.18 ±4.77 ng/mL) was higher than UMA (6.36 ±2.29 ng/mL; p <0.0001) and did not differ from UY (20.26 ±6.20 ng/mL). Relative BF of MS was lower than UMA (12.71 ±4.07% vs. 22.13 ±4.18%; p <0.0001). Sirt1 was negatively correlated with chronological age (r  = -0.735; p <0.0001) when combining UY and UMA in the analysis. However, when Sirt1 of MS and UY was analyzed together, no significant relationship between Sirt1 and chronological age was observed (r =  -0.243; p  = 0.083). Sirt1 correlated inversely with BF (r =  -0.743; p <0.0001) for UY and UMA. Stepwise multiple regression revealed that being either a young or master athlete and body adiposity are possible predictors of Sirt1 levels. MS and UY were associated with higher levels of Sirt1, while UMA and increased BF were associated with lower levels of this enzyme. The relationships among Sirt1, BF, and chronological age of young and middle-aged non-athletes were not statistically significant when the middle-aged participants were MS. These findings suggest possible links between Sirt1 and body composition, which may play roles in the rate of biological aging. Highlights Lower levels of Sirt1 are associated with higher body fat.Master athlete lifestyle seems to promote higher Sirt1 Levels.