Impact of aerobic exercise, sex, and metabolic syndrome on markers of oxidative stress: results from the Brain in Motion study.

Oxidative stress may be involved in disease pathology and dependent on both modifiable and nonmodifiable factors. This study aimed to assess exercise-induced changes in markers of oxidative stress among older, sedentary adults and to determine the effects of metabolic syndrome (MetS) status, aerobic capacity, age, sex, and weight on these biomarkers. Two hundred and six participants (means ± SE; 66.8 ± 6.4 yr, 104 women) of the Brain in Motion study underwent a 6-mo aerobic exercise intervention. At three time points, venous blood samples were collected and analyzed for markers of oxidative stress [advanced oxidation protein products (AOPP), malondialdehyde (MDA), 3-nitrotyrosine (3-NT) and antioxidant status: catalase, uric acid (UA), superoxide dismutase (SOD), and ferric-reducing ability of plasma (FRAP)]. AOPP levels significantly decreased after 6 mo of aerobic exercise (P = 0.003). This decrease was not modified by MetS status (P = 0.183). Subjects with MetS possessed significantly higher levels of AOPP (P < 0.001), MDA (P = 0.004), and FRAP (P = 0.049) across the intervention (months 0-6). Men possessed significantly higher levels of FRAP (P < 0.001), catalase (P = 0.023), and UA (P = 0.037) across the intervention (months 0-6). Sex-MetS status interaction analyses revealed that the effect of MetS is highly sex dependent. These findings are multifaceted because the effect of MetS status seems distinctly different between sexes, pointing to the importance of acknowledging modifiable and nonmodifiable factor differences in individuals who possess conditions where oxidative stress may be part of the etiology.NEW & NOTEWORTHY Oxidative stress is implicated in a myriad of conditions, namely cardiovascular disease risk factors. This article details the effect of aerobic exercise, sex, and metabolic syndrome on markers of oxidative stress. We conclude that 6 mo of aerobic exercise significantly decreased oxidative stress, and further, that there is an effect of metabolic syndrome status on oxidative stress and antioxidant status levels, which are highly dependent on the sex of the individual.