Electroacupuncture Inhibition of Hypertension is Slow Onset and Long-Lasting

Abstract

Our recent study shows that electroacupuncture (EA) at P 5-6 + S 36-37 acupoints with low current and low frequency once a week for 4–8 weeks can effectively reduce systolic blood pressure (SBP) and diastolic blood pressure (DBP) in patients with mild to moderate HTN (BP: > 140 90 < 110 mmHg). Thirty six hypertensive patients without medication were assessed with 24 h ambulatory BP monitoring, and EA at P 5-6 and S 36-37 given once weekly for 30 min for eight weeks. The 8-week treatment significantly decreased peak and average SBP/24 h in 25 patients (~70%). The peak and average DBP/24 h also decreased significantly. Heart rate was unchanged. After termination of EA treatment, SBP remained reduced for an additional four weeks but over the next four weeks returned to near pretreatment levels. Eleven patients (~30%) did not respond to the EA treatment. Both SBP and DBP/24 h were not reduced in 28 other patients treated with control acupoints (LI 6-7 + G 37-39). These data suggest that EA at select acupoints, performed once weekly for 8 weeks, significantly reduced BP. This beneficial effect was slow in onset but persisted for a prolonged period of time. The mechanism of the slow onset and long-lasting EA effect is complicated. It likely is related to opioids and GABA in rostral ventrolateral medulla (rVLM), neural circuit between arcuate nucleus in hypothalamus and rVLM, and preproenkephalin mRNA in rVLM. In subgroups of patients we measured plasma catecholamines (n = 25), renin (n = 22) and aldosterone (n = 18). After eight weeks of EA, plasma concentrations of nor-epinephrine, renin and aldosterone decreased significantly (P < 0.05) in the EA-responders in contrast to low-responders. Thus, the renal sympathetic function and renin-aldosterone system were related to the long-lasting effect of EA inhibition.