The association between metabolic syndrome severity and oxidative stress induced by maximal exercise testing – a cross-sectional study

Abstract

Purpose: Oxidative stress (OS) has been implicated in the pathogenesis of metabolic syndrome (MetS). The acute change in OS biomarkers due to exercise, known as exercise-induced OS (EIOS), is postulated to be a more appropriate marker of OS compared to spot OS measures. These studies objectives were to investigate EIOS in participants with MetS and compare the associations between EIOS, spot OS measures and MetS severity.

Methods: Sixty-three participants with MetS had MetS severity assessed using the MetS Z-score. Participants undertook a cardiorespiratory fitness test ($\mathrm{V}$O₂peak) to volitional exhaustion (∼8–12 minutes). Plasma OS (total F2-isoprostanes (IsoP), protein carbonyls (PCs)) and antioxidant (glutathione peroxidase (GPx), total antioxidant status (TAS)) biomarkers were measured from samples obtained before and five minutes post-$\mathrm{V}$O₂peak test. Wilcoxon’s signed-rank tests were used to determine changes in OS markers.

Results: There were no significant (p > 0.05) changes in OS or antioxidant biomarkers from pre- to post-exercise (median (interquartile range): IsoP –15.5 (–71.8 to 47.8) pg/mL; PC –0.01 (–0.16 to 0.13) nmol/mg protein; GPx 0.76 (–4.94 to 9.82) U/L, TAS 0.03 (0.00–0.05) mmol/L).

Conclusions: A $\mathrm{V}$O₂peak test to exhaustion failed to induce OS in participants with MetS. There were no associations between MetS severity and spot OS or EIOS biomarkers.

Keywords:

• F2-isoprostanes
• protein carbonyls
• antioxidants
• cardiorespiratory fitness
• exercise

Disclosure statement

The authors have reported that they have no relationships relevant to the contents of this article to disclose.

Additional information

Funding

This study was funded by an unrestricted research grant from the from the Coca-Cola company. The funders had no role in the design and conduct of the study.