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

Last updated: October 6, 2025
Sponsor: University of Arizona
Overall Status: Active - Not Recruiting

Phase

N/A

Condition

Sleep Apnea Syndromes

Circulation Disorders

Williams Syndrome

Treatment

Inspiratory Muscle Strength Training

Clinical Study ID

NCT04932447
1200000220
1R01AG065346-01A1
  • Ages > 50
  • All Genders

Study Summary

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.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Age 50 and older

  • Ability to understand study procedures and to comply with them for the entire lengthof 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 remainweight stable throughout the study

  • No change in anti-hypertensive medications or other medications (prescription ordosing) in the prior 3 months and willingness to maintain current medication regimenthroughout the study

  • Absence of unstable clinical disease as determined by medical history, physicalexamination, and blood chemistries

  • Total cholesterol <240 mg/dL

  • Fasting plasma glucose <300 mg/dL

Exclusion

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, chronickidney 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 3months

  • Regular/vigorous aerobic exercise (> 4 bouts/week, >30 min/bout at high workload >6METS)

Study Design

Total Participants: 122
Treatment Group(s): 1
Primary Treatment: Inspiratory Muscle Strength Training
Phase:
Study Start date:
September 01, 2021
Estimated Completion Date:
September 30, 2026

Study Description

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.

Connect with a study center

  • Arizona Respiratory and Neurophysiology Laboratory

    Tucson, Arizona 85724
    United States

    Site Not Available

  • Arizona Respiratory and Neurophysiology Laboratory

    Tucson 5318313, Arizona 5551752 85724
    United States

    Site Not Available

Map preview placeholder

Not the study for you?

Let us help you find the best match. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.