Abstract P3057: Slow Breathing Training Reduces Blood Pressure in Healthy Normotensive Subjects

Slow breathing, an integral part of different body mind relaxation practices, might modulate autonomic tone and lower bp. It is unknown if extended exhalation technique (E>I) will have different effects than common slow breathing (E=I). We hypothesized that E>I will have a greater impact on blood pressure. We studied 86 healthy participants (41±4 years, 76% female) randomly assigned to E=I (n=41) or E>I (n=45) daily exercise guided by Yoga teachers over 12 weeks. We measured blood pressure, autonomic tone by spectral analysis of heart rate and blood pressure variability and cardio-vagal baroreflex sensitivity by spontaneous sequence technique (BRS) at baseline and at 12 weeks. For comparison, we included two groups without breathing interventions: normotensives (NTN), n=14 SBP 114± 5 mm Hg and hypertensives (HTN), n=15 SBP 141± 3 mm Hg, that were studied on two separate visits at least one month apart. SBP significantly decreased at 12 weeks for both intervention groups, 3.5 ± 6.6 mm Hg for E>I (p<0.001) and 3.5 ± 5.5 mm Hg for E=I (p<0.001). No differences were found between groups or for the controls. The blood pressure drop was significantly greater among subjects with higher initial SBP [SBP=123±2 mm Hg, n=24, (HBP)] as compared with lower SBP [SBP=96±1 mmHg, n=24 (LBP)]: SBP changed 6.3 ± 7.3 mm Hg (p<0.001) for HBP, with no significant drop for LBP (figure). BRS changed differently by time and group with increase in E>I (E>I: 3.07±1.2 ms/mmHg, E=I:-0.24±0.8 ms/mmHg, p(time)=0.013, p(timeXgroup)=0.019.In conclusion, 12 weeks of slow breathing exercises resulted in a significant reduction of blood pressure and changes in baroreflex sensitivity independently of the type of breathing.