Breathe: Slow Paced Breathing to Lower Blood Pressure

Not Applicable

Completed

Brief Summary: The purpose of this study is to investigate the nature of the physiological reasons for the decreases in resting blood pressure that can result from systematic practice of computer-guided breathing exercises or meditative relaxation.

Detailed Description: In this randomized clinical trial, persons with moderately elevated blood pressure were trained in either computer-guided breathing exercises or meditative relaxation to breathing. The computer-guided breathing exercise involves listening to tones of ascending and descending pitch to which breathing is entrained to low frequencies over a 15 minute interval. The meditative relaxation involves passive attention to natural breathing for the same duration. Participants will perform these breathing exercises daily at home for four weeks. Before and after the intervention, respiratory, cardiovascular, and urinary endogenous digitalis-like factors will be systematically recorded to determine the extent to which chronic neuroendocrine changes underlie the reductions in blood pressure.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

More than one antihypertensive medication
Beta blockers, angiotensin converting enzyme inhibitors or angiotensin receptor blockers
History of coronary artery disease, heart failure, stroke, angina or coronary revascularization
Kidney disease, defined as plasma creatinine > 1.5mg/dL
Diabetes, defined by insulin or oral hypoglycemic medication or blood sugar > 126mg/dL
Pulmonary disease, defined as chronic obstructive pulmonary disease, bronchitis, asthma, or use of inhaler
Upper respiratory infection during past 30 days
Medication that affects central nervous system function
Steroid use
Current pregnancy or lactation within past six months
Current birth control medication or hormone replacement therapy
Condition that in the judgment of the Principal Investigator is incompatible with the research study

Arm && Interventions

Group	Intervention	Description
Device Guided Breathing	RESPeRATE	Individual breathing rate was determined from an expandable band around the torso connected to a commercially available device (RESPeRATE, Lod, Israel) that presented distinctive tones via earphones.
Control Group	Guided Breathing	Control group were instructed to sit in the same manner passively attend to their breathing, and silently repeat 'one' during each exhalation. If other thoughts came to mind, they were instructed to calmly attend to their breathing.

Primary Outcome Measures

Name	Time	Method
Breathing Rate	After 15 minutes of guided breathing or control task	Breathing rate was monitored continuously via inductive plethysmography.

Secondary Outcome Measures

Name	Time	Method
Minute Ventilation	After 15 minutes of guided breathing or control task	Minute Ventilation was continuously monitored via inductive plethysmography
End Tidal CO2 (PetCO2)	After 15 minutes of guided breathing or control task	End tidal CO2 was monitored continuously using a respiratory gas monitor