Effects of acupressure on gastric myoelectrical activity in healthy humans

Objective. Acupressure at Neiguan point (P6) has been used as an antiemetic in Eastern countries and many studies have reported its effectiveness on gastrointestinal symptoms. The aim of the present study was to investigate the effects of acupressure on gastric myoelectrical activity in healthy humans. Material and methods. Fifteen healthy volunteers (9 M, 6 F) served as subjects. Acupressure at P6 was applied for 1 min followed by 1 min of rest, and this alternating sequence was continued for a total of 30 min. Electrogastrogram (EGG) was recorded for 30 min before ("baseline"), during ("acupressure") and after ("recovery") the application of acupressure. Heart rate variability (HRV) was also recorded to analyze autonomic nervous activities. Results. The percentage of normal 3 cycles per minute slow wave (%NSW) was changed significantly by the application of acupressure (86.5 +/- 2.4, 92.3 +/- 1.2, 92.8 +/- 1.9% in the baseline, acupressure and recovery periods, respectively, p = 0.0424). The %NSW was significantly larger in the acupressure and the recovery periods than in the baseline period (p < 0.03). The changes in %NSW from the baseline to the acupressure (r = -0.8598, p < 0.001) and to the recovery (r = -0.6422, p < 0.01) periods were negatively correlated with the baseline %NSW. There was no change in HRV. Conclusions. Acupressure at P6 increased %NSW of gastric myoelectrical activity. The negative correlation between the baseline value and the change in %NSW may extrapolate a possible normalizing effect of acupressure on impaired gastric myoelectrical activity in symptomatic patients.