Physical activity affects the vasculature through mechanisms related to
nitric oxide bioavailability, oxidative stress, and
inflammation; with endothelial function at the centre of this triad. In a South African setting, with the prevalence of
hypertension and physical inactivity being alarmingly high, we aimed to investigate relationships of vascular function with markers of oxidative stress,
inflammation and
nitric oxide synthesis capacity in physically active and inactive groups. Based on the 2010 World Health Organisation guidelines, black and white school teachers were divided into physically active (n = 84) and physically inactive (n = 132) groups. Twenty-four-hour blood pressure (24 h BP), total peripheral resistance and Windkessel compliance were measured. Markers of oxidative stress,
inflammation and
nitric oxide synthesis capacity were analysed. Windkessel compliance (p = 0.041) and
homoarginine (p = 0.006) were higher in the physically active group. In the same group, 24 h diastolic BP associated with total
glutathione (β = 0.17; p = 0.056), and 24 h BP (systolic blood pressure: β = 0.23, p = 0.006; diastolic blood pressure: β = 0.22, p = 0.019) associated with
homoarginine. In the physically inactive group, 24 h BP (systolic blood pressure: β = 0.26, p < 0.001; diastolic blood pressure: β = 0.23, p = 0.007) associated with
symmetric dimethylarginine (SDMA). These associations were independent of
inflammation. Despite only reaching moderate physical activity levels, vascular function and
nitric oxide synthesis capacity were more favourable in the physically active population compared to the physically inactive population. These results may suggest that even moderate physical activity could increase
nitric oxide synthesis capacity, which in turn may mitigate the development of
cardiovascular disease in this population.