Blood Pressure Responses to Slow Breathing in Young Healthy Individuals: Is there an Effect of Sex?

Abstract

Slow breathing has been recommended by the American Heart Association as an effective adjunctive approach for the treatment of hypertension. RESPeRATE is an FDA‐approved device that guides the user into a slow breathing pattern, sensitizing the baroreflex and thus acutely reducing blood pressure (BP). Limited research has demonstrated the effectiveness of this device in inducing sustained reductions in BP in older adults with hypertension. However, whether responsiveness to device‐guided slow breathing is affected by sex remains unknown. Therefore, the purpose of this study was to compare the effectiveness of the RESPeRATE device in acutely reducing BP between women and men. We hypothesized that slow breathing would result in larger decreases in BP in men than in women, given that men typically have higher resting blood pressure than women. We examined BP at baseline and during the last minute of a 15‐min slow breathing session guided by the RESPeRATE device in 9 young healthy subjects: 5 women (mean±SD age: 23±1 y, BMI: 22±1 kg/m2) and 4 men (mean±SD age: 24±2 y, BMI: 26±6 kg/m2). There were no differences in age (p=0.8) or BMI (p=0.2) between groups. We assessed the effects of sex and slow breathing on mean arterial pressure (MAP), systolic BP (SBP), and diastolic BP (DBP) using two‐way ANOVAs. Compared to men, women had lower resting MAP (77±4 vs. 87±7 mmHg; p=0.03) and DBP (64±3 vs 77±6 mmHg; p<0.01) with a trend towards lower SBP (103±4 vs 110±9 mmHg; p=0.1). Respiration rate was similar between sexes at rest (women: 15±4 breaths/min, men: 13±3; p=0.4). Respiration rate decreased during slow breathing (−7.4±1.6 breaths/min, main effect of slow breathing: p<0.01) with no effect of sex (p=0.4). Slow breathing was associated with reduced MAP (women: 68±12 mmHg, men: 79±10; main effect of slow breathing: p=0.02, effect of sex: p=0.1), SBP (women: 93±21 mmHg, men: 96±17; main effect of slow breathing: p=0.04, effect of sex: p=0.6), and DBP (women: 56±10 mmHg, men: 69±8; main effect of slow breathing: p<0.01). However, we observed a significant effect of sex on DBP (p<0.01), as women maintained lower DBP than men during slow breathing. In conclusion, the RESPeRATE device acutely reduced BP in young healthy individuals, and these effects were consistent in both women and men. That is, despite women starting at lower resting BPs, slow breathing was equally effective in reducing BP in young healthy women and men. Our results provide preliminary support for the efficacy of the RESPeRATE device as an intervention to reduce blood pressure in young healthy individuals of both sexes.Support or Funding InformationThis project was supported by a Natural Sciences and Engineering Research Council Discovery Grant (CWU). TEA & YC were supported by the McGill Department of Kinesiology and Physical Education Graduate Excellence Fellowship.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.