Abstract
Background: In the Indian subcontinent, 118 million people are with hypertension, and this figure is anticipated to double by 2025. Yoga has been widely claimed to play a role in the prevention and management of psychosomatic, stress-induced, and lifestyle disorders such as hypertension.

Aims and Objective: To study the effect of 12 weeks of yoga therapy as a lifestyle intervention on cardiac autonomic functions in patients of essential hypertension.

Materials and Methods: Subjects with hypertension from the Medicine Outpatient Department of the Jawaharlal Institute of Postgraduate Medical Education and Research were randomized into control and yoga groups. The control group was treated only with the allopathic medicines. The yoga group was given 12 weeks of yoga therapy module designed by JIPMER Institute Advanced Center for Yoga Therapy Education and Research along with the routine medical treatment. The participants’ blood pressure and cardiac autonomic function were recorded before and after the 12 weeks of the study period.

Result: No significant change was observed in the body weight (BW), body mass index (BMI), abdominal circumference, and waist–hip ratio (WHR) in both the control and yoga groups at the end of the 12 week-study period. There was a significant decrease in the resting systolic pressure (SP), diastolic pressure (DP), rate pressure product (RPP), and mean arterial pressure (MAP) in the yoga group. In contrast, there was no significant change in the SP, DP, RPP, and MAP of the control group. High frequency (HF) power, total spectral power, and HF normalized units (nu) showed a significant increase in the yoga group. Low frequency (LF) power, HF power, and LF (nu) showed a significant (p < 0.05) decrease in the yoga group at the end of the 12-week yoga therapy.

Conclusion: Twelve weeks of yoga therapy reduced both the SP and DP in the yoga group. Furthermore, yoga therapy increased the heart rate variability and vagal tone and decreased the sympathetic tone in the subjects with hypertension. At the same time, it increased both the parasympathetic and sympathetic reactivity.

Key words: Autonomic Function Tests; Hypertension; Yoga; HRV