Trial to assess long-term effects of inspiratory muscle training on BP in sleep apnea

A new clinical trial is underway to evaluate the long-term effectiveness of inspiratory muscle training to reduce blood pressure and improve cardiovascular health in adults with obstructive sleep apnea.

The phase 2 clinical trial will be conducted at the University of Arizona College of Medicine – Tucson. E. Fiona Bailey, PhD, professor in the department of physiology at the University of Arizona College of Medicine was awarded a 5-year, $3.4 million grant from the National Institute on Aging to build on her group’s previous research that demonstrated a respiratory workout entailing 30 breaths per day may lower BP, according to a press release.

Inspiratory muscle strength training was originally devised for use by athletes and people with breathing issues, such as asthma, bronchitis and chronic obstructive pulmonary disease. It involves five sets of six breaths with 1 minute between each set. Participants in the new trial will be required to complete 30 breaths per day 5 days per week. This training aids in participants’ lung muscles stretching in small increments until they can overcome the resistance and take deeper breaths, according to the release.

“This started back in 2015, when a PhD student and I started doing some work with inspiratory muscle strength training, initially to improve airflow through the upper airway. But in fact, what we were noticing was that people’s blood pressure was dropping as they completed the training,” Bailey, who is also an associate editor for the Journal of Applied Physiology, told Healio. “After weeks 1, 2 and 3, blood pressure was declining, and we thought that was a more interesting observation.”

Until 2015, most research regarding inspiratory muscle strength training focused on improving athletic performance without patients experiencing fatigue. Only recently have researchers begun evaluating the effects of inspiratory muscle strength training on improving BP.

The phase 2 clinical trial aims to evaluate the long-term effectiveness of inspiratory muscle strength training in adults with OSA, as individuals with sleep apnea experience nightly oxygen deprivation, which can contribute to increased risk for developing higher BP and CVD.

Currently, researchers at the University of Arizona College of Medicine – Tucson are in the process of recruiting participants aged 50 to 80 years with OSA and above-normal BP in the Tucson area. Participants will undergo CV, respiratory and sleep health screenings and will undergo random assignment to high-resistance training or low-resistance training. These participants will complete inspiratory muscle strength training at home for 24 weeks and researchers will follow-up thereafter to assess BP reductions and the duration of the reductions, according to the release.

Bailey said inspiratory muscle strength training is time efficient and can be performed by anybody and in most places, including the standing and sitting positions. In addition, this training can be completed in 30 minutes per week.

“Inspiratory muscle strength training is easily done,” Bailey said. “It’s very brief training, with rather profound beneficial effects on cardiovascular health.”

Reference:

• College of Medicine – Tucson Clinical Trial to Study a Simple Breathing Exercise for Obstructive Sleep Apnea. https://healthsciences.arizona.edu/newsroom/news-releases/2021/college-medicine-tucson-clinical-trial-study-simple-breathing-exercise. Published Aug. 3, 2021. Accessed Sept. 15, 2021.

For more information:

E. Fiona Bailey, PhD, can be reached at ebailey@arizona.edu.