Regular exercise, overweight/obesity and sedentary lifestyle cause adaptive changes in thiol–disulfide homeostasis

: Dynamic thiol-disulfide homeostasis is considered to have critical roles in maintenance of physiological functioning. We aimed to reveal whether there is any specific aberration in thiol-disulfide homeostasis in three distinct categories of individuals, including those who 1) exercise regularly (fitness group), 2) have a sedentary lifestyle (sedentary group) and 3) are overweight or obese (overweight/obese group). 72 male individuals were included in the study, 21 of whom were in fitness group, 28 of whom were overweight or obese and 23 of whom had a sedentary lifestyle. Plasma native thiol (-SH) and total thiol [(-SH) + (-S-S-)] levels were quantitatively determined. Total thiol levels in sedentary group were significantly lower than those in overweight/obese (p<0.05) and fitness groups (p<0.001). Also, disulfide values in fitness group were significantly higher than those in sedentary and overweight/obese groups (p<0.005, p<0.05). On the other hand, disulfide level, reduced and oxidized thiol ratios and oxidation/reduction ratio in fitness group differed significantly from the other groups (p<0.05). Thiol-disulfide homeostasis varies depending on lifestyle. The results of our study indicate that higher total thiol and disulfide levels are conspicuously distinctive features of thiol-disulfide homeostasis in individuals exercising regularly.