Effect of needling at an acupuncture point zusanli (ST-36) on blood pressure and heart rate variability in patients with hypertension: A randomized placebo-controlled study

Background: Acupuncture is a traditional healing system used to prevent and treat hypertension in many countries. Acupuncture point "Zusanli (ST-36)" is used to nourish blood and yin. However, no known studies reported the effect of needling at only ST-36 on cardiovascular parameters. Objectives: This study was performed to find the effectiveness of ST-36 on blood pressure (BP) and heart rate variability (HRV) in patients with hypertension. Methods: A total of 100 participants with primary hypertension aged between 30 years and70 years were randomly assigned into either acupuncture group (AG) or control group (CG). AG underwent only one session of bilateral needling at ST-36 acupuncture point for duration of 20 minutes, while the CG underwent only one session of bilateral needling at non-acupuncture point for the same duration. Results: Results of the study showed a significant reduction in systolic blood pressure, pulse pressure and mean arterial pressure in the AG compared to the CG. In addition, a significant increase in intervals between adjacent QRS complexes (R-R interval), and a significant reduction in heart rate were observed in AG, unlike CG. Conclusions: Needling at ST-36 acupuncture point may improve cardiovascular function better than needling at non-acupuncture points in patients with hypertension.