Study On The Effect Of Transcutaneous Acupoint Electrical Stimulation On Gastric Receptivity And Autonomic Nerves

Transcutaneous electrical acustimulation synchronized with inspiration improves gastric accommodation impaired by cold stress in healthy subjectsBackground and Aims:Impaired gastric accommodation(GA)is recognized as one of major pathophysiologies in functional dyspepsia and gastroparesis.Stress has been reported to alter GA.A previous study demonstrated an ameliorating effect of transcutaneous electrical acustimulation(TEA)on cold stress-induced impairment in GA.The aim of this was to investigate whether TEA synchronized with inspiration(STEA),a method known to enhance vagal activity,was more effective in improving cold stress-induced impairment in GA and dyspeptic symptoms in healthy subjects.Methods: After routine physical examination,excluding organic and systemic diseases of stomach and whole body,fifteen healthy subjects,aged 25-47 years,10 males and 5 females,were enrolled.Each of fifteen healthy subjects(10 men,25–47years)was studied in five randomized sessions: control(37℃warm nutrient liquid),4℃ cold nutrient liquid(CNL),CNL+sham-TEA,and CNL+TEA,CNL+STEA.The subjects were requested to drink Ensure until reaching maximum satiety.The electrogastrogram(EGG)and electrocardiogram(ECG)were recorded to assess gastric slow waves(GSW)and autonomic functions,respectively.Dyspeptic symptoms were graded at the end of each session.TEA was performed via acupuncture point,PC6 using following parameters: pulse frequency of 25 Hz,width of 0.6ms,and amplitude of2~10m A(depending on tolerability),train-on of 2 s and off of 3s.STEA was performed using the same parameters as TEA but asking the subjects to breathe in when they sensed each stimulation train.Results:1)GA(maximum amount of liquid intake)was reduced with the CNL in comparison withthe warm drink(913.3±265.2ml vs740.0±195.2ml,P=0.002)but increased with TEA(892.0±226.6ml,P=0.007 vs CNL)and STEA(1038.7±248.3ml,P=0.004 vs CNL);STEA was more potent than TEA in improving GA(P<0.001).2)The percentage of normal GSW was reduced from76.8±13.1% to 59.8±13.3% with CNL(P=0.001)but improved with both TEA(70.8±11.9%,P=0.001 vs CNL)and STEA(74.8±12.2%,P<0.001 vs CNL);STEA was more potent in improving GSW than TEA(P=0.008).3)The total symptom score was increased significantly from127±33 with warm drink to 203±26 with CNL(P<0.001)but reduced with both TEA(143±16,P<0.001)and STEA(117±20,P<0.001);STEA was more effective in reducing the total symptom score than TEA(P<0.01)as well as individual symptom scores,including bloating(P=0.001),postprandial fullness(P=0.009)and nausea(P=0.048).4)The CNL did not alter autonomic functionsin comparison with the warm drink,nor did TEA in comparison with CNL.However,STEA significantly increased vagal activity(0.38±0.14 vs 0.30±0.14,P=0.007)and decreased sympathetic activity(0.62±0.14 vs 0.70±0.14,P=0.006)compared with TEA.Conclusions: TEA synchronized with inspiration is more potent than TEA in improving cold stress-induced impairment in GA and GSW and dyspeptic symptoms,and might be a novel noninvasive therapy for treating stress-induced dysmotility and dyspeptic symptoms.The additive effects of STEA over TEA is probably attributed to its enhancement in vagal activity.Transcutaneous electrical acustimulation on ST36 improves gastric accommodation and vagal activity impaired by emotional stress in healthy subjectsBackground and Aims: Impaired gastric accommodation(GA)is recognized as one of major pathophysiologies in functional dyspepsia and gastroparesis.Stress has been reported to alter GA.However,it is unknown about the effect of transcutaneous electrical acustimulation(TEA)at ST36 on the improvement of emotional stress-induced impairment in GA and vagal activity.Therefore,the aim of this study was to investigate whether TEA at ST36 was effective in improving emotional stress induced impairment in gastric accommodation,dyspeptic symptoms and autonomic dysfunction in healthy subjects.Methods and materials: Each of twenty one healthy subjects was studied in there randomized sessions: control,emotional stress+sham TEA,emotional stress+TEA.The subjects were requested to drink Ensure until reaching maximum satiety.Each TEA/sham-TEA session included a 15-min acclimation period,a 30-min baseline recording,a 30-min preprandial period with TEA/sham-TEA treatment and emotional stress,a satiety drinking test and a 30-min postprandial period with TEA/sham-TEA and emotional stress.The electrogastrogram(EGG)and electrocardiogram(ECG)were recorded to assess gastric slow waves(GSW)and autonomic functions,respectively.Results: a)GA was reduced with the emotional stress in comparison with the control session but increased with TEA;b)The total symptom score of bloating,postprandial fullness,nausea,abdominal pain increased significantly in stress+sham TEA session in comparison with the control session and decreased in the stress+TEA session,furthermore,TEA was effective in reducing the individual symptom score including bloating,postprandial fullness and nausea;c)GSW were impaired by the emotional stress and improved in TEA session.The impairment of GSW by emotional stress was attributed to an increase in bradygastria,tachygastria and a decline in percentage of normal gastric slow wave and dominant power,furthermore,the improvement in GSW with TEA was also attributed to a reduction in bradygastria,tachygastria and an increase in percentage of normal gastric slow wave and dominant power as well.d)TEA significantly enhanced vagal activity and suppressed sympathetic activity compared with sham TEA.Conclusions: Emotional stress could impaire gastric accommodation and autonomic function and gastric myoelectrical activity.TEA at ST36 could improve the impairment,might be a novel noninvasive therapy for treating stress-induced dysmotility and dyspeptic symptoms.The effects of TEA might probably attribute to its enhancement in vagal activity.