Acupuncture Research

WOMEN'S HEALTH

Acupuncture at Neiguan (P6) Increases Vagal Modulation

Huang ST, et al. Department of Chinese Medicine, Chang Gung Memorial Hospital, Kaohsiung, Taiwan.

Acupuncture at Neiguan (P6) point has been demonstrated to decrease nausea and vomiting, both of which are related to vagal modulation. A study was conducted to determine whether acupuncture at P6 could improve vagal modulation by using heart rate variability analysis.

A comparison was made of the heart rate variability measures of 39 subjects receiving acupuncture at P6, 38 subjects receiving sham acupuncture, and 34 subjects receiving no treatment at all. A normalized high-frequency power was used as the index of vagal modulation, and a low-/high-frequency power ratio was used as the index of sympathovagal balance. The normalized high-frequency power after acupuncture increased significantly from 28.1 +/- 12.6 nu (mean +/- SD) to 30.7 +/- 14.1 nu in the P6 acupuncture group, but not in the sham acupuncture (30.6 +/- 13.7 nu versus 31.8 +/- 13.8 nu) or no-treatment group (30.1 +/- 15.0 nu versus 30.1 +/- 15.7 nu).

In both the P6 and sham acupuncture groups, the average RR interval (the intervals between consecutive R waves in the electrocardiogram) increased significantly after acupuncture. However, in the no-treatment group, there was no statistical difference in all heart rate variability measures in the initial and later sessions.

In conclusion, acupuncture at P6 can increase vagal modulation.