Effect Of Acute Ingestion Of Caffeine On Acupuncture Analgesia

Objective:To reveal the effect of acute ingestion of caffeine on acupuncture analgesia.Methods:Cross design was used in this study.Thirty subjects who met the inclusion criteria were randomly assigned to the A group and the B group and every group had fifteen samples. The interventions of the A group were to drink coffee (containing 200 mg caffeine) and acupuncture on the point of left Zusanli and the B group were to drink water and acupuncture on the point of left Zusanli.The human pain model was induced by potassium ion. The Change of pain threshold will be measured with Potassium Pain Tester at the time of the baseline,30 minutes after drinking coffee or water,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed.A week washout period later, the A group and the B group exchanged intervention measures and recorded the pain threshold.The group of coffee intaking was called the test group, and the group of pure water intaking was called the control group.Statistical analysis used SPSS21.0 to process.Results:1.The results of pain threshold on the point of left Zusanli:The pain threshold of the test group on the time of the baseline,30 minutes after drinking coffee,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.40±0.16,0.30±0.19,0.35±0.26,0.37±0.23,0.33±0.20,0.31±0.15.The change rate of pain threshold reduced 25% at 30 minutes after drinking coffee (p>0.05) and reduced 12%(p>0.05),8%(p>0.05),18%(p>0.05) at 10,20,30 minutes during acupuncture, while the change rate of pain threshold was reduced 23% at 30 minutes after acupuncture intervention (p<0.05).The pain threshold of the control group on the time of the baseline,30 minutes after drinking pure water,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.39±0.19,0.38±0.15,0.59±0.21,0.63±0.24,0.67± 0.19,0.23±0.14.The change rate of pain threshold was no significant difference at 30 minutes after drinking pure water (p>0.05) and increased 51%,62%,72% at 10,20, 30 minutes during acupuncture (P<0.05), while the change rate of pain threshold reduced at 30 minutes after acupuncture intervention(p>0.05).Compare the test group and the control group, baseline and drinking coffee or water 30min later the pain threshold had no significant difference,while acupuncture 10min,20min,30min, resting after 30 min, the differences were statistically significant (P< 0.05).2.The results of pain threshold on the point of right Zusanli:The pain threshold of the test group on the time of the baseline,30 minutes after drinking coffee,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.38±0.17,0.30±0.11,0.33±0.20,0.39±0.22,0.37± 0.19,0.32±0.20.The change rate of pain threshold reduced 21% at 30 minutes after drinking coffee (p>0.05) and reduced 13%(p>0.05),-2%(p>0.05),2%(p>0.05) at 10,20,30 minutes during acupuncture, while the change rate of pain threshold was reduced 16% at 30 minutes after acupuncture intervention (p>0.05).The pain threshold of the control group on the time of the baseline,30 minutes after drinking pure water,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.37±0.15,0.37±0.16,0.53±0.20,0.56±0.19,0.61± 0.16,0.37±0.17.The change rate of pain threshold was no significant difference at 30 minutes after drinking pure water (p>0.05) and increased 43%,51%,65% at 10,20, 30 minutes during acupuncture (P<0.05), while the change rate of pain threshold reduced at 30 minutes after acupuncture intervention (p>0.05).Compare the test group and the control group,baseline and resting after 30 min the pain threshold had no significant difference,while drinking coffee or water 30min later,acupuncture 10min, 20min,30min, the differences were statistically significant (P<0.05).3.The results of pain threshold on the point of left Hegu:The pain threshold of the test group on the time of the baseline,30 minutes after drinking coffee,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.25±0.17,0.21±0.16,0.25±0.19,0.24±0.21,0.23±0.21,0.20±0.14.The change rate of pain threshold reduced 16% at 30 minutes after drinking coffee (p>0.05)and reduced 0%(p>0.05),4%(p>0.05),8%(p>0.05)at 10,20,30 minutes during acupuncture, while the change rate of pain threshold was reduced 20% at 30 minutes after acupuncture intervention (p>0.05).The pain threshold of the control group on the time of the baseline,30 minutes after drinking pure water,10,20,30 minutes during acupuncture and 30 minutes after acupuncture intervention completed were 0.27±0.16,0.26±0.15,0.39±0.26,0.44±0.25,0.45±0.23,0.25±0.16.The change rate of pain threshold was no significant difference at 30 minutes after drinking pure water (p>0.05) and increased 44%(p>0.05),63%(P< 0.05),67%(P < 0.05) at 10,20,30 minutes during acupuncture, while the change rate of pain threshold reduced at 30 minutes after acupuncture intervention (p>0.05).Compare the test group and the control group,baseline and drinking coffee or water 30min later and resting after 30 min, the pain threshold had no significant difference,while acupuncture 10min,20min,30min, the differences were statistically significant (P< 0.05).Conclusions:Acute intaking of 200mg caffeine can inhibit the analgesic effect of acupuncture.The degree of decrease was more obvious in 30 minutes of acupuncture.