Impact of BMI and Cardiorespiratory Fitness on Oxidative Stress in Plasma and Circulating Exosomes Following Acute Exercise.

Simple Summary: The regulation of oxidative stress at rest and in response to a single session of exercise is vital for cardiovascular and metabolic health. However, the lack of regular physical activity and exercise and the presence of obesity are known to negatively impact oxidative stress under both conditions. In the present study, the oxidative stress response in circulation and within exosome-like extracellular vesicles (ELVs) released by contracting skeletal muscle during exercise was examined following maximal intensity treadmill running. As a result, we demonstrate that aerobically untrained individuals with obesity exhibit an altered oxidative stress response to maximal treadmill running compared to aerobically untrained and aerobically trained individuals without obesity. Similarly, body mass index, an index of obesity, but not cardiorespiratory fitness, was associated with an adverse oxidative response at rest and immediately following maximal treadmill running. These findings suggest that obesity, more than improved cardiorespiratory fitness, differentially regulates plasma and circulating ELV indices of oxidative stress prior to and immediately following acute maximal treadmill exercise. The impact of cardiorespiratory fitness (VO2max) and obesity on indices of oxidative stress in plasma and circulating exosome-like extracellular vesicles (ELVs) were examined following acute exercise. Indices of oxidative stress in plasma and isolated plasma ELVs were examined in aerobically trained (NW-Tr; n = 15) and untrained (NW-UTr; n = 18) normal-weight individuals and aerobically untrained individuals with obesity (Ob-Utr; n = 10) prior to and immediately following acute maximal treadmill running. Following exercise, ELV flotillin-1 expression (p = 0.008) and plasma total antioxidant capacity (TAC; p = 0.010) increased more in NW-UTr compared to NW-Tr and Ob-UTr participants, whereas plasma protein carbonyls (PC) decreased more in Ob-UTr compared to NW-Tr and NW-UTr groups. ELV glutathione (GSH) concentrations decreased more in NW-Tr compared to NW-UTr and Ob-UTr participants (p = 0.009), whereas lipid peroxidase (LPO) concentrations increased more in Ob-UTr compared to NW-Tr and NW-UTr participants (p = 0.003). Body mass index (BMI) was associated negatively with plasma TAC and PC (p < 0.05) and positively with ELV LPO concentration responses (p = 0.009). Finally, plasma-to-total (plasma + ELV) GSH ratios decreased in Ob-UTr compared to NW-Tr and NW-UTr participants (p = 0.006), PC ratios increased in NW-Tr and NW-UTr compared to Ob-UTr subjects (p = 0.008), and reactive oxygen/nitrogen species ratios increased in NW-UTr and decreased in Ob-UTr participants (p < 0.001). BMI, independently of VO2max, differentially regulates indices of oxidative stress within plasma and circulating ELVs prior to and immediately following acute maximal treadmill exercise. [ABSTRACT FROM AUTHOR]