# Inspiratory muscle strength training for lowering blood pressure in hypertensive mid-life adults

> **NIH NIH R21** · UNIVERSITY OF COLORADO · 2020 · $193,278

## Abstract

Project Summary
 This R21 application is responsive to NIA PA-18-153 Prevention Research in Mid-Life Adults. Systolic
hypertension, defined as systolic blood pressure (SBP) ≥130 mmHg, affects 65-70% of mid-life adults (50-64
years), and is a major modifiable risk factor for cardiovascular diseases, cognitive decline/dementia, renal
dysfunction and other chronic conditions of aging. Many mid-life adults do not engage in time-intensive healthy
lifestyle practices that would reduce SBP due to competing personal and professional time demands that tend
to peak during this period of life. The number of mid-life adults is rapidly increasing, necessitating the
development of novel, time- and effort-efficient lifestyle interventions to prevent and treat systolic hypertension.
 Co-I Dr. Fiona Bailey has found that brief (~5 min/day) inspiratory muscle strength training (IMST)
consisting of 30 breaths at 75% of maximal inspiratory pressure (PIMAX), 5-6 days/week for 6 weeks lowers
casual (resting) SBP by 12 mmHg in patients with obstructive sleep apnea (OSA), with excellent adherence
(<10% dropout, 97% of training sessions completed). A primary cause of systolic hypertension with aging is
arterial stiffening, demonstrated by increased carotid-femoral pulse wave velocity (CFPWV). Findings in OSA
patients and healthy young adults show that IMST reduces systemic vascular resistance and plasma
norepinephrine (PNE), a marker of sympathetic activity and vascular smooth muscle constrictor, suggesting
actions on vascular tone/stiffness. Oxidative stress-mediated inhibition of nitric oxide (NO) bioavailability and
its tonic vasodilatory influence is another key determinant of arterial stiffening that may play a role in IMST-
induced improvements in SBP. However, the short-term and long-lasting effects of IMST on SBP, arterial
function, sympathetic activity and oxidative stress, and its safety and adherence, in mid-life adults is unknown.
 We propose a small randomized, double-blind, sham-controlled, parallel design clinical trial to assess the
efficacy of 6-weeks of IMST (75% PIMAX) vs. sham training (15% PIMAX) (n=23/group) for decreasing SBP and
improving arterial function in mid-life adults with systolic hypertension. We hypothesize that IMST will lower
SBP and CFPWV, and increase brachial artery flow-mediated dilation (FMDBA), a measure of NO-mediated
endothelium-dependent dilation, and reduce oxidative stress and PNE. We further hypothesize that IMST will
be safe, well-tolerated, and associated with high rates of adherence, and that a portion of the improvements in
SBP and arterial function will persist 6-weeks after completing post-intervention testing.
Aim 1: To measure casual SBP (primary outcome) and 24-hour ambulatory SBP (secondary outcome) before,
after and 6-weeks following IMST vs. sham training. Safety, tolerability and adherence will also be assessed;
Aim 2: To measure CFPWV, FMDBA and PNE before, after and 6-weeks following IMST vs. sham training;
A...

## Key facts

- **NIH application ID:** 9856963
- **Project number:** 5R21AG061677-02
- **Recipient organization:** UNIVERSITY OF COLORADO
- **Principal Investigator:** DOUGLAS R SEALS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $193,278
- **Award type:** 5
- **Project period:** 2019-02-01 → 2021-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9856963

## Citation

> US National Institutes of Health, RePORTER application 9856963, Inspiratory muscle strength training for lowering blood pressure in hypertensive mid-life adults (5R21AG061677-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9856963. Licensed CC0.

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