Acupuncture effects on reflex responses to mental stress in humans

In animal studies, acupuncture has been shown to be sympathoinhibitory, but it is unknown if acupuncture is sympathoinhibitory in humans. Nineteen hea lthy volunteers underwent mental stress testing pre- and postacupuncture. M uscle sympathetic nerve activity (MSNA), blood pressure, and heart rate dur ing mental stress were compared pre- and postacupuncture. Control acupunctu re consisted of acupuncture at nonacupoints and "no-needle" acupuncture. Ac upuncture had no effect on resting MSNA, blood pressure, or heart rate. Aft er real acupuncture, the increase in mean arterial pressure (pre- vs. posta cupuncture 4.5 vs. 1.7 mmHg, P < 0.001), but not MSNA or heart rate, was bl unted during mental stress. Similarly, following nonacupoint acupuncture, t he increase in mean arterial pressure was blunted during mental stress (5.4 vs. 2.9 mmHg, P < 0.0003). No-needle acupuncture had no effect on these va riables. In conclusion, acupuncture at traditional acupoints, nonacupoints, and no-needle acupuncture does not modulate baseline MSNA or MSNA response s to mental stress in normal humans. Acupuncture significantly attenuates t he increase in blood pressure during mental stress. Needling nonacupoints, but not "no-needle" acupuncture, have a similar effect on blood pressure.