High-intensity intermittent exercise regulates oxidative stress and improves endothelial progenitor cell function in patients with essential hypertension

Background Vascular endothelial damage associated with endothelial progenitor cell dysfunction is considered as an initiating step of hypertension and target organ damage, in which oxidative stress plays a key role. High-intensity intermittent exercise is an effective prevention and treatment method of various chronic diseases; however, little attention has been paid to its effects and mechanisms on endothelial progenitor cells.

Objective To observe the effect of high-intensity intermittent exercise on the function of endothelial progenitor cells in patients with hypertension and explore the mechanism of oxidative stress.

Methods A total of 60 patients with essential hypertension were randomly divided into a control group and an exercise group. The control group received conventional drug treatment (including diuretics, calcium blockers, and beta-blockers), and the exercise group performed high-intensity intermittent exercise for 8 weeks (3 times·week⁻¹) in addition to the treatment plan of the control group. Before and after intervention, brachial artery flow-mediated vasodilation (FMD) was used to evaluate vascular endothelial function; venous blood was sampled to perfrom circulating endothelial progenitor cell counts; endothelial progenitor cells were cultured in vitro, and the modified Boyden chamber assay and Matrigel lumen formation assay were used to detect their migration and tube formation ability, superoxide fluorescent anion probe method to detect reactive oxygen species levels, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining method to detect cell apoptosis, Western blotting to determine protein expression of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2, NADPH oxidase 4, and superoxide dismutase.

Results Four patients (13.3%) in the control group and 2 patients (6.7%) in the exercise group dropped out; the completion rate of the exercise group's training plan was 94.9%. Compared with the before-intervention indicators, blood pressure decreased, brachial artery FMD increased, number of circulating endothelial progenitor cells increased, their migration and tube formation ability were enhanced, reactive oxygen species levels and cell apoptosis rate were reduced, NADPH oxidase 2 and NADPH oxidase 4 protein expressions were down-regulated, and superoxide dismutase protein expression was up-regulated in the after-intervention exercise group, and the differences were all statistically significant (P < 0.05). There was no significant difference in the above indicators in the control group between before and after intervention (P > 0.05).

Conclusion High-intensity intermittent exercise regulates oxidative stress mediated by NADPH oxidase, improves endothelial progenitor cell function, and restores vascular endothelial disorders in patients with essential hypertension.