102 Participants Needed

Inspiratory Muscle Strength Training for High Blood Pressure

DH
NM
Overseen ByNarissa McCarty, MS
Age: 18+
Sex: Any
Trial Phase: Academic
Sponsor: University of Colorado, Boulder
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)

Trial Summary

What is the purpose of this trial?

Above-normal systolic blood pressure (SBP), defined as SBP \>/= 120 mmHg, is the major modifiable risk factor for cardiovascular disease, stroke, cognitive decline/dementia, and other chronic health problems. Despite the availability of treatments to lower SBP, over 75 percent of adults with above-normal SBP fail to control BP, which has led to a nearly 50 percent increase in the number of deaths attributable to BP over the past decade. Therefore, above-normal SBP is a major public health burden. * Greater than 65 percent of adults 50 years of age and older have above-normal SBP. The number of adults age 50 years and older is rapidly increasing, predicting a continued increase in above-normal SBP driven morbidity and mortality in the absence of effective treatment strategies. This makes developing novel SBP-lowering therapies an urgent biomedical research priority. * Increasing SBP is closely linked to vascular dysfunction, observable as impaired endothelial function, increased large-elastic artery stiffness, and impaired cerebrovascular function. Declines in these functions play a large role in the increased risk of chronic disease associated with above-normal SBP. The primary mechanism responsible for SBP-induced vascular dysfunction is thought to be oxidative stress-associated inhibition of nitric oxide bioavailability. Therefore, to have the largest biomedical impact, new SBP-lowering therapies should also improve vascular function by decreasing oxidative stress. * Healthy lifestyle practices, such as conventional aerobic exercise, maintaining a healthy diet, or reducing sodium intake, are all first-line strategies to lower SBP. Importantly, these lifestyle practices also improve vascular function, in large part by reducing oxidative stress. However, adherence to healthy lifestyle practices is poor, with adherence to guidelines generally between 20 to 40 percent in adult Americans. The greatest reported barrier to meeting healthy lifestyle guidelines is lack of time. Therefore, time-efficient interventions have great promise for promoting adherence, reducing SBP, and improving other physiological functions. * High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise. However, these results need to be confirmed in an appropriately powered clinical trial with a longer, guideline-based treatment duration. Furthermore, the influence of IMST on functions impaired by above-normal SBP (endothelial, cerebrovascular, cognitive) needs to be determined, as do the mechanisms through which IMST exerts beneficial effects. * Accordingly, we will conduct a randomized, blinded, sham-controlled, parallel group design clinical trial to assess the efficacy of 3-months of IMST (75 percent maximal inspiratory pressure) vs. brisk walking (40-60% heart rate reserve; an established healthy lifestyle strategy) for lowering SBP and improving endothelial, cerebrovascular, and cognitive function in adults age 50 years and older with above-normal SBP. I hypothesize IMST will lower SBP and improve endothelial function by decreasing oxidative stress and increasing nitric oxide bioavailability. I also hypothesize IMST will improve cerebrovascular and cognitive function, and that these improvements will be related to reductions in SBP and improvements in endothelial function. I also expect adherence to the intervention to be excellent (over 80 percent of all training sessions completed at the appropriate intensity). * To test my hypothesis, I will recruit 102 adults age 50 years and older who have SBP \>/= 120 mmHg. Subjects will undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function. Innovative mechanistic probes including pharmaco-dissection with vitamin C, analysis of biopsied endothelial cells, and high-throughput metabolomics, will be performed to assess oxidative stress and nitric oxide bioavailability at baseline. * After baseline testing, subjects will be randomized to perform either 3-months of high-resistance IMST or brisk walking. Subjects will train 6 days/week with one training session supervised in the laboratory and the other 5 performed unsupervised at home. Following 3 months of training, subjects will redo all the tests that were done during baseline testing to assess training-induced changes in SBP, physiological functions, and underlying mechanisms.

Will I have to stop taking my current medications?

The trial does not require you to stop taking your current medications. In fact, participants must maintain their current medication regimen without changes during the study.

What data supports the effectiveness of the treatment Inspiratory Muscle Strength Training for High Blood Pressure?

Research shows that high-resistance inspiratory muscle strength training (IMST) can significantly lower blood pressure, with reductions in systolic blood pressure by 9 mmHg and diastolic blood pressure by 4 mmHg after six weeks of training. These improvements were observed in a wide range of adults, indicating that IMST is effective in lowering blood pressure.12345

Is inspiratory muscle strength training safe for humans?

Inspiratory muscle strength training (IMST) is generally safe and well-tolerated in humans, with studies showing high adherence and no significant adverse effects reported in both healthy and at-risk adults.12678

How does inspiratory muscle strength training differ from other treatments for high blood pressure?

Inspiratory muscle strength training (IMST) is unique because it involves breathing exercises that strengthen the muscles used for inhaling, which can lower blood pressure by improving respiratory endurance and reducing cardiovascular strain. Unlike traditional medications, this non-drug approach can be done at home with a simple device and has shown significant blood pressure reductions in just six weeks.128910

Research Team

DH

Daniel H Craighead, PhD

Principal Investigator

University of Colorado, Boulder

Eligibility Criteria

Adults aged 50 or older with high blood pressure (systolic BP of at least 120 mmHg), a BMI under 40, and stable weight are eligible for this trial. They must be non-smokers, not on changing medication regimens, able to consent, and have no history of uncontrolled hypertension or regular vigorous exercise.

Inclusion Criteria

Your blood pressure when you are relaxed is 120 mmHg or higher.
I am healthy except for high blood pressure.
I haven't changed my medications or doses in the last 3 months and will keep them the same.
See 6 more

Exclusion Criteria

I am under 50 years old.
Your blood pressure doesn't react normally during exercise, or it becomes very high during exercise.
You do intense aerobic exercise more than four times a week for at least 30 minutes each time.
See 2 more

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Testing

Subjects undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function.

1-2 weeks
1 visit (in-person)

Treatment

Participants perform either 3-months of high-resistance IMST or brisk walking. Subjects train 6 days/week with one training session supervised in the laboratory and the other 5 performed unsupervised at home.

12 weeks
12 visits (1 per week, in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including redo of all baseline tests to assess training-induced changes.

4 weeks
1 visit (in-person)

Treatment Details

Interventions

  • Brisk walking
  • Inspiratory muscle strength training
Trial OverviewThe trial is testing whether a time-efficient breathing exercise called Inspiratory Muscle Strength Training (IMST) can lower systolic blood pressure more effectively than brisk walking. Participants will do one of these activities for three months to see if there's an improvement in blood pressure and vascular health.
Participant Groups
2Treatment groups
Experimental Treatment
Active Control
Group I: Inspiratory muscle strength trainingExperimental Treatment1 Intervention
Using a handheld device, participants will perform 30 breaths a day at 75% of maximal inspiratory pressure, six days a week, for three months.
Group II: Brisk walkingActive Control1 Intervention
Participants will walk for 25 minutes a day, six days a week, for three months at a target heart rate of 40-60% heart rate reserve. Heart rate will be monitored with a heart rate monitor.

Find a Clinic Near You

Who Is Running the Clinical Trial?

University of Colorado, Boulder

Lead Sponsor

Trials
128
Recruited
29,600+

Findings from Research

Inspiratory muscle training (IMT) significantly reduces systolic blood pressure (SBP) by an average of 12.55 mmHg and diastolic blood pressure (DBP) by 4.77 mmHg in patients with hypertension, based on a meta-analysis of 8 randomized controlled trials involving 215 patients.
Low-intensity IMT is particularly effective, showing greater reductions in both SBP and DBP compared to medium-high-intensity IMT, suggesting it could be a valuable auxiliary treatment for managing hypertension.
Effects of inspiratory muscle training in patients with hypertension: a meta-analysis.Zheng, S., Zhang, Q., Li, S., et al.[2023]
High-resistance inspiratory muscle strength training (IMST) significantly lowers systolic blood pressure (SBP) by 9 mmHg and diastolic blood pressure (DBP) by 4 mmHg in adults over 6 weeks, with effects noticeable as early as week 2.
IMST also improves inspiratory muscle strength, as indicated by increased maximal inspiratory pressure (PIMAX), and is effective across a wide range of adult ages and health statuses, making it a promising intervention for managing blood pressure.
A multi-trial, retrospective analysis of the antihypertensive effects of high-resistance, low-volume inspiratory muscle strength training.Craighead, DH., Tavoian, D., Freeberg, KA., et al.[2023]
Inspiratory muscle training (IMT) significantly improved respiratory muscle strength and functional capacity in 29 patients with pulmonary arterial hypertension (PAH) over a 6-week program, leading to better performance in activities like walking.
Patients undergoing IMT reported reduced fatigue and dyspnea, indicating that this training is a safe and effective treatment option for enhancing quality of life in PAH patients.
Inspiratory muscle training in pulmonary arterial hypertension.Saglam, M., Arikan, H., Vardar-Yagli, N., et al.[2015]

References

Effects of inspiratory muscle training in patients with hypertension: a meta-analysis. [2023]
A multi-trial, retrospective analysis of the antihypertensive effects of high-resistance, low-volume inspiratory muscle strength training. [2023]
Inspiratory muscle training in pulmonary arterial hypertension. [2015]
Effects of inspiratory muscle training in patients with heart failure. [2011]
Efficacy of inspiratory muscle training in chronic heart failure patients: a systematic review and meta-analysis. [2018]
Time-Efficient Inspiratory Muscle Strength Training Lowers Blood Pressure and Improves Endothelial Function, NO Bioavailability, and Oxidative Stress in Midlife/Older Adults With Above-Normal Blood Pressure. [2022]
Six Months of Inspiratory Muscle Training to Lower Blood Pressure and Improve Endothelial Function in Middle-Aged and Older Adults With Above-Normal Blood Pressure and Obstructive Sleep Apnea: Protocol for the CHART Clinical Trial. [2022]
Comparison of inspiratory muscle strength training effects between older subjects with and without chronic obstructive pulmonary disease. [2016]
Effectiveness and safety of inspiratory muscle training in patients with pulmonary hypertension: A systematic review and meta-analysis. [2022]
A short course of high-resistance, low-volume breathing exercise extends respiratory endurance and blunts cardiovascular responsiveness to constant load respiratory testing in healthy young adults. [2023]