Breathing Training for Improving Cardiovascular Health in Older Adults With Sleep Apnea

NCT ID: NCT04932447

Last Updated: 2025-10-08

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

NA

Total Enrollment

122 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-09-01

Study Completion Date

2026-09-30

Brief Summary

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This clinical research study will investigate the effects of respiratory strength training on blood pressure and cardiovascular health in adults who are 50 years of age and older and have been diagnosed with moderate or severe obstructive sleep apnea.

Detailed Description

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Exercise has well-documented benefits for systolic blood pressure (SBP) and cardiovascular health. Whereas current guidelines advocate \~150 min moderate intensity exercise/week, our preliminary data show \~5 min/day of inspiratory muscle strength training (IMST) for 6 weeks lowers casual (resting) SBP by \~12 mmHg.

This simple approach to lowering BP could be applied to almost any population however we are studying IMST in older adults with obstructive sleep apnea (OSA). OSA is an ideal population to target because OSA prevalence is growing and because snoring and apneas result in chronic intermittent hypoxemia that drives sympathetic nervous system (SNS) hyperactivity, endothelial dysfunction and hypertension. These substantive risks for cardiovascular disease are compounded by poor adherence to the mainstay treatment continuous positive airway pressure (\<50%), obesity, fatigue and a robust intolerance for exercise.

Our findings in healthy young adults (n=50) show IMST-related reductions in BP are mediated by decreases in systemic vascular resistance, suggesting changes in vascular tone and function. Consistent with this hypothesis, our results from a pilot clinical trial in adults with OSA (n=24) show IMST-related reductions in plasma norepinephrine levels (PNE) and muscle sympathetic nerve activity (MSNA), both markers of SNS activity. Our preliminary mechanistic assessments indicate IMST may lower circulating concentrations of other vasoconstrictor factors and increase nitric oxide (NO)-mediated endothelium-dependent dilation. And, findings in a novel endothelial cell culture model, point to increases in NO and declines in reactive oxygen species (ROS) and oxidative stress. However, it is unknown if: 1) IMST lowers casual and 24-h (ambulatory) SBP in older adults with OSA; 2) the reductions in SBP are long-lasting; 3) arterial stiffness, NO-mediated endothelial dilation and/or oxidative stress are improved; and 4) if adherence in this population is high long term.

In this randomized, double-blind clinical trial we will establish the efficacy of high-intensity IMST (75% maximum inspiratory pressure, \[PImax\]) 5 days/week for 24 weeks vs. low-intensity IMST (15%PImax) (n=61/group) for lowering SBP in adults (\>50 years) with above normal BP and OSA. We hypothesize that IMST will lower SBP via reductions in SNS activity and circulating vasoconstrictor factors, improvements in vascular function, and reductions in oxidative stress/inflammation and that reductions in SBP will be sustained 4 and 12 weeks post-intervention.

Conditions

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Obstructive Sleep Apnea Hypertension

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Participants will be randomly allocated using a 1:1 ratio to A) High-Intensity Training Group (75 % maximal inspiratory pressure) or B)Low-Intensity Training Group (15% maximal inspiratory pressure)
Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

DOUBLE

Participants Investigators
This is a randomized double-blinded clinical trial.

Study Groups

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Training Group A

Participants will perform their respiratory training (high-intensity, low-volume IMST) on a hand-held respiratory training device.

Group Type EXPERIMENTAL

Inspiratory Muscle Strength Training

Intervention Type BEHAVIORAL

30 breaths/ day, 5 days/week for 24 weeks.

Training Group B

Participants will perform their respiratory training (low-intensity, low-volume IMST) on a hand-held respiratory training device.

Group Type SHAM_COMPARATOR

Inspiratory Muscle Strength Training

Intervention Type BEHAVIORAL

30 breaths/ day, 5 days/week for 24 weeks.

Interventions

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Inspiratory Muscle Strength Training

30 breaths/ day, 5 days/week for 24 weeks.

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Age 50 and older
* Ability to understand study procedures and to comply with them for the entire length of the study
* Ability to provide informed consent;
* Willing to accept random assignment to condition
* AHI ≥15
* Individuals with who are unwilling or unable to adhere to CPAP
* Individuals who are adherent to CPAP therapy (i.e., 4 hours/night on 70%/nights over 30 days in the first 3 months of initial usage)
* Individuals who are adherent to mandibular advancement device each night
* Above-normal SBP (i.e., SBP ≥120)
* BMI ≤40 kg/m2
* Weight stable in the prior 3 months (\<3.0 kg weight change) and willing to remain weight stable throughout the study
* No change in anti-hypertensive medications or other medications (prescription or dosing) in the prior 3 months and willingness to maintain current medication regimen throughout the study
* Absence of unstable clinical disease as determined by medical history, physical examination, and blood chemistries
* Total cholesterol \<240 mg/dL
* Fasting plasma glucose \<300 mg/dL

Exclusion Criteria

* Age \<50
* AHI \<15
* Individuals with central or mixed sleep disordered breathing
* Severe hypoxemia (\<80% for \>10% of recording time) during sleep
* ESS \>15
* SBP ≥160 or DBP ≥120
* Current smoker
* Chronic overt and poorly controlled medical condition (e.g., diabetes, chronic kidney disease, cancer, congestive heart failure)
* Cheyne-Stokes Respiration
* Alcohol or illegal drug dependence or abuse
* Uncontrolled thyroid disease or change in thyroid medication within previous 3 months
* Regular/vigorous aerobic exercise (\> 4 bouts/week, \>30 min/bout at high workload \>6 METS)
Minimum Eligible Age

50 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Institutes of Health (NIH)

NIH

Sponsor Role collaborator

National Institute on Aging (NIA)

NIH

Sponsor Role collaborator

University of Colorado, Boulder

OTHER

Sponsor Role collaborator

University of Arizona

OTHER

Sponsor Role lead

Responsible Party

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Elizabeth Fiona Bailey, PhD

Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Elizabeth F Bailey, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Arizona

Locations

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Arizona Respiratory and Neurophysiology Laboratory

Tucson, Arizona, United States

Site Status

Countries

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United States

References

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DeLucia CM, DeBonis DR, Schwyhart SM, Bailey EF. Acute cardiovascular responses to a single bout of high intensity inspiratory muscle strength training in healthy young adults. J Appl Physiol (1985). 2021 Apr 1;130(4):1114-1121. doi: 10.1152/japplphysiol.01015.2020. Epub 2021 Feb 18.

Reference Type BACKGROUND
PMID: 33600284 (View on PubMed)

Ramos-Barrera GE, DeLucia CM, Bailey EF. Inspiratory muscle strength training lowers blood pressure and sympathetic activity in older adults with OSA: a randomized controlled pilot trial. J Appl Physiol (1985). 2020 Sep 1;129(3):449-458. doi: 10.1152/japplphysiol.00024.2020. Epub 2020 Jul 30.

Reference Type BACKGROUND
PMID: 32730174 (View on PubMed)

DeLucia CM, De Asis RM, Bailey EF. Daily inspiratory muscle training lowers blood pressure and vascular resistance in healthy men and women. Exp Physiol. 2018 Feb 1;103(2):201-211. doi: 10.1113/EP086641. Epub 2018 Jan 15.

Reference Type BACKGROUND
PMID: 29178489 (View on PubMed)

Vranish JR, Bailey EF. Inspiratory Muscle Training Improves Sleep and Mitigates Cardiovascular Dysfunction in Obstructive Sleep Apnea. Sleep. 2016 Jun 1;39(6):1179-85. doi: 10.5665/sleep.5826.

Reference Type BACKGROUND
PMID: 27091540 (View on PubMed)

Vranish JR, Bailey EF. Daily respiratory training with large intrathoracic pressures, but not large lung volumes, lowers blood pressure in normotensive adults. Respir Physiol Neurobiol. 2015 Sep 15;216:63-9. doi: 10.1016/j.resp.2015.06.002. Epub 2015 Jun 22.

Reference Type BACKGROUND
PMID: 26112283 (View on PubMed)

Tavoian D, Ramos-Barrera LE, Craighead DH, Seals DR, Bedrick EJ, Alpert JS, Mashaqi S, Bailey EF. 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. Front Cardiovasc Med. 2021 Nov 24;8:760203. doi: 10.3389/fcvm.2021.760203. eCollection 2021.

Reference Type DERIVED
PMID: 34901220 (View on PubMed)

Related Links

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https://redcap.link/breathe

Pre-screening questionnaire for interested participants

Other Identifiers

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1R01AG065346-01A1

Identifier Type: NIH

Identifier Source: secondary_id

View Link

1200000220

Identifier Type: -

Identifier Source: org_study_id

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