Comparison of the effects of inspiratory muscle strength training and aerobic exercise training on vascular function in patients with hypertension

Purpose: This study examined the comparative effects of aerobic exercise training (AET) and inspiratory muscle strength training (IMST) as an emerging exercise modality for improving vascular function in hypertensive patients. Methods: Twenty-eight hypertensive patients (aged 61 ± 7 years; 9 males, 19 females) were randomized to AET (n = 14, 70% of heart rate reserve for 30 min/session, 5 days/week) or IMST (n = 14, 30 breaths/session at 75% of maximal inspiratory pressure, 5 days/week) groups. Both supervised interventions lasted 8 weeks. Vascular outcome measurements included endothelial function, measured by brachial artery flow-mediated dilation (FMD) and arterial stiffness, assessed by carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx). These measurements were taken at baseline and 8-weeks post-intervention. Results: The mean ± SD change in FMD from baseline to post-intervention improved similarly in both groups (IMST, + 1.60 ± 2.2%; p < 0.05 and AET, + 1.05 ± 1.7%; p < 0.05), with no significant difference between the groups (p = 0.46). However, the IMST group showed a significant improvement in cfPWV (0.38 ± 0.6 m/s; p < 0.05) and AIx@75 (2.6 ± 4.0%; p < 0.05), which was not observed in the AET group. Conclusion: Both IMST and AET similarly improved endothelial function. IMST was slightly more effective than AET in improving arterial stiffness. Taken together and findings support the efficacy of IMST as a time-efficient strategy for enhancing vascular function in hypertensive patients.