The proposed study will assess the effects of yoga postures and slow, deep breathing in altering oxidative stress, vascular function, and blood pressure.
The purpose of this study is to determine the mechanism by which yoga lowers blood pressure in hypertensive adults. Free radicals and enzyme activity will be analyzed from isolated immune cells and blood pressure and vascular health will be assessed at baseline and at weeks 4, 8, and 12 during the interventions or control conditions. Sedentary adults (ages 30-60 years) with elevated blood pressure or stage I hypertension will be recruited and randomized to 12 weeks of yoga, video-based breathing, or app-based breathing conditions. Yoga classes will be completed 3 times weekly at Texas State University and slow, deep breathing interventions will be completed at home 5 times weekly. Participants assigned to the app-based breathing group will also complete 5- 20-minute breathing exercises per week at home before being re-randomization at week 12. Three testing sessions will be completed at the beginning of the study: 1) familiarization and screening for elevated blood pressure or hypertension and other exclusion criteria; 2) confirmation of elevated blood pressure or hypertension via addition seated blood pressure measurements and 24-hour ambulatory blood pressure and 3-day physical activity monitoring; and 3) blood marker assessment and endothelial function measurements. All outcomes will be measured at baseline and at 4-week intervals throughout the 12-week data collection period in all 3 groups. At each follow up visit after randomization, testing will be completed over the course of 2 sessions: 1) ambulatory blood pressure monitor and physical activity monitoring and 2) blood marker and endothelial function measurements. At the end of the waitlist sham/control period, waitlisted participants will be rerandomized to yoga or slow, deep breathing interventions. Once re-randomized, participants in each group will complete follow up testing 4,8, and 12 weeks into their respective interventions.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
30
12-week yoga intervention in which 60-minute classes are completed at Texas State University 3 times per week
12-week home-based intervention in which 5 weekly 20-minute breathing sessions are completed
12-week home-based intervention in which 5 weekly 20-minute breathing sessions are completed
Cardiovascular Physiology Laboratory-Texas State University
San Marcos, Texas, United States
Change in peripheral blood mononuclear cell reactive oxygen species
Blood draws will be performed at baseline and at weeks 4, 8, and 12 during the study after randomization and analyzed for free radicals after white blood cells are separated from whole blood.
Time frame: Baseline and week 4, 8, and 12 measurements
Change in peripheral blood mononuclear cell NADPH oxidase cell NADPH oxidase enzyme activity
A portion of the white blood cells isolated from a whole blood sample will be frozen and later analyzed for enzyme activity. This will be completed for blood samples obtained at baseline and weeks 4, 8, and 12.
Time frame: Baseline and week 4, 8, and 12 measurements
Change in 24-hour blood pressure
An automated cuff will be worn for 24 hours while the devices takes automatic measurements every 30 minutes.
Time frame: Baseline and week 4, 8, and 12 measurements
Change in flow-mediated dilation
A cuff will placed around the forearm while an ultrasound probe is held on the upper arm to obtain a brachial artery image. The forearm cuff will be inflated for 5 minutes, then ultrasound images of the upper arm will be obtained for 3 minutes after cuff deflation.
Time frame: Baseline and week 4, 8, and 12 measurements
Change in microvascular endothelial function/thermal hyperemia
A small probe will be secured on the forearm and gradually heated for 45 minutes.
Time frame: Baseline and week 4, 8, and 12 measurements
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