Changes in Cardiovascular Autonomic Activity and Reactivity in Essential Hypertensive Patients after Yogic Practices

Abstract

Globally prevalence of essential hypertension (EH) is increasing. It is one of the leading risk factors for global mortality. Several modifiable factors including overweight, obesity, physical inactivity contribute to the high prevalence rates of hypertension. Despite long‐term normalization of blood pressure by anti‐hypertensive drugs, there exists autonomic dysfunction. It is reported that yogic practices decrease BMI, BP and modify other risk factors in EH patients. We aimed to study whether combined easy yogic practices improve cardiovascular autonomic regulation both activity and reactivity in EH patients. Fifty essential hypertensive patients on similar pharmacotherapy were randomized into yoga (n=25, age 46.73±7.72 years) and control (n=25, age 46.1±7.01 years) groups. Yoga group practiced meditation, pranayama and few easy asanas for 40 min/day for one month. Control group did not practice yoga or any relaxation procedures. In both the groups cardiac autonomic activity was assessed using short‐term heart rate variability (HRV) by both time domain and spectral analysis, and reactivity using deep breathing (DBT), Valsalva Maneuver (VM), Handgrip (HGT) and Lying to standing (LST) tests before start of the study and after one month of the study. Institutional Ethical Committee approved the study. Age, BMI, BP, HR, and respiratory rate were comparable between both the groups before start of the study. The SBP (135.42 ± 15.5 vs 125.85 ±14.68, p=0.044), DBP (98.28 ± 12.95 vs 82.85 ± 10.09, p=0.019) and BMI (25.97 ± 2.96 vs 24.87 ± 2.70, p=0.039) decreased in yoga group after one month of yoga practice. Time domain measures of HRV, which are markers of cardiac parasympathetic activity [SDNN: 26.8(18.33.3) vs 35.2(26.87–38.3) ms, p=0.013; rMSSD: 25.2(8.95–33.3) vs 38.2(29.0–68.97) ms, p=0.024] increased in yoga group after yoga practice. Similarly, in spectral analysis, HF power [210(115.75–352.0) vs 400(141.0–518.25) ms2, p=0.0 46; Total power: 650.5(227.75–863.0) vs 862(634.5–1317), p=0.006] were increased in yoga group after yoga practice, whereas, there were no significant changes in markers of sympathetic activity; LF nu and LF/HF ratio after yoga practice. The E:I ratio (1.18 ± 0.08 vs 1.26 ± 0.09, p=0.003) and Valsalva ratio, which are indicators of parasympathetic reactivity also increased in yoga group after yoga practice. In conclusion, both parasympathetic activity and reactivity increased in EH patients after a month of yoga practice. It indicates that combined easy yoga practices improve cardiovascular autonomic regulation by increasing cardiac parasympathetic activity.Support or Funding InformationBPKIHS Research grantThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.