Comparison of Hemodynamic Changes During Acupuncture Stimulation in Supine or Sitting Position in Human Subjects.

Objective: Position change influences acupuncture-induced heart rate (HR) reduction, which is caused by a somatoautonomic reflex. However, the influences of position on the hemodynamic system-including HR, blood pressure (BP), and cardiac output (CO) during acupuncture-remains unclear. This study comprehensively compared cardiovascular changes induced by acupuncture in human beings supine and sitting positions. Materials and Methods: Comprehensive measurements were made of 30 healthy male volunteers, including HR, stroke volume (SV), and BP, in a supine posture for 15 minutes. Manual acupuncture stimulation was performed at the left LI-10 point for 1 minute. After at least 1 week, the same protocol was performed with all subjects in a sitting position. Results: Preacupuncture, there were increases in HR and BP, and decreases in SV and CO in the sitting position, compared with the supine position. Acupuncture stimulation induced HR reduction more when the subjects were in the sitting position, compared with them in the supine position. Acupuncture-induced increase in SV and decrease in diastolic BP were not different in either position. In the sitting position, CO decreased during acupuncture, compared with preacupuncture; this did not occur in the supine position. Conclusions: The effects of acupuncture on the hemodynamic system changed between the supine and sitting positions in healthy young men. Autonomic nervous-tone influences acupuncture-induced cardiovascular changes through physiologic responses, including the somatoautonomic reflex and the baroreflex.