Inspiratory Muscle Strength Training for High Blood Pressure
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?
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
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
Exclusion Criteria
Timeline
Screening
Participants are screened for eligibility to participate in the trial
Baseline Testing
Subjects undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function.
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.
Follow-up
Participants are monitored for safety and effectiveness after treatment, including redo of all baseline tests to assess training-induced changes.
Treatment Details
Interventions
- Brisk walking
- Inspiratory muscle strength training
Find a Clinic Near You
Who Is Running the Clinical Trial?
University of Colorado, Boulder
Lead Sponsor