Effects of HIIT and MICT on cardiovascular function in essential hypertension: roles of inflammation, oxidative stress, and RAS axis

Objective To compare the effects of High Intensity Interval Training (HIIT) and Moderate Intensity Continuous Training (MICT) on blood pressure homeostasis, cardiovascular structure, and function, and to explore the underlying neuro-humoral regulatory mechanisms in patients with essential hypertension (EH). Methods A total of 56 EH patients were randomly (1:1) assigned to the MICT (35 min) or HIIT (1 × 10 min with 2 min intervals) for 8 weeks, three times per week. The primary outcome was the change in flow-mediated dilation (FMD). Blood pressure, traditional cardiovascular risk factors, cardiovascular structure and function, as well as neural, specific humoral, and nonspecific humoral regulation were assessed. Results Among 56 patients with EH who were randomized, 54 (96.4%) completed the 8-week evaluation. After an 8-week intervention, the improvement in FMD was significantly greater in the HIIT group compared with the MICT group (mean difference: 0.85% [95% CI, 0.50–1.21]). HIIT showed favored changes in nitric oxide, FMD, and endothelin-1, brachial-ankle pulse wave velocity, peak systolic velocity, corrected QT Interval, Ratio of Early Diastolic Mitral Valve Peak Flow Velocity to Early Diastolic Myocardial Velocity, angiotensin-(1–7), and C-reactive protein in EH patients (all P < 0.05). Both HIIT and MICT significantly improved systolic blood pressure, pulsatility index, resistive index, angiotensin II, and norepinephrine in EH patients (all P < 0.05), with no statistically significant differences between the two groups (all P > 0.05). Conclusion Both HIIT and MICT yielded comparable effects on lowering systolic blood pressure and regulating neurohumoral factors. FMD was improved to a greater extent with HIIT, which also showed superior efficacy in arterial stiffness, hemodynamics, cardiac diastolic function, and inflammatory biomarkers. Clinical Trial Registration https://www.chictr.org.cn , identifier ChiCTR2500097077.