A Comparative Study on the Immediate Effects of Electroacupuncture at Sanyinjiao (SP6), Xuanzhong (GB39) and a Non-Meridian Point, on Menstrual Pain and Uterine Arterial Blood Flow, in Primary Dysmenorrhea Patients

Abstract

The objective of this study was to compare the effects of Sanyinjiao (SP6), Xuanzhong (GB39), and an adjacent non-meridian point on menstrual pain and uterine arterial blood flow in primary dysmenorrhea patients. The design of the study was a prospective, randomized controlled trial. The setting of the study was the Shandong Institute of Medical Imaging, Jinan, China. The patients were 52 women with primary dysmenorrhea. Women received electroacupuncture (EA) at SP6 (n=13), GB39 (n=14), and an adjacent non-meridian point (n=12), respectively, for 10 minutes when scored ≥40 on a 100-mm visual analog scale (VAS), and for 30 minutes on the next 2 days. There was no EA in the waiting list group (n=13). Primary outcomes were menstrual pain, resistance index (RI), and the ratio between peak systolic to end-diastolic flow velocity (S/D) in uterine arteries. Secondary outcomes included verbal rating scale (VRS) and retrospective symptom scale (RSS). The SP6 group had a highly significant reduction in VAS scores compared with the waiting list group (-23.19mm, 95% confidence interval [CI]-32.06 to -14.33, P<0.0001), GB39 group (-18.58mm, 95% CI -27.29 to -9.88, P<0.0001) and the non-meridian point group (-20.78mm, 95% CI -29.82 to -11.73, P<0.0001), respectively. A significant reduction in VRS scores was found in the SP6 group compared with the GB39 group (P=0.034) and the non-meridian point group (P=0.038). There were no significant differences of RI, S/D-values and RSS scores among the four groups (P>0.05). EA at SP6 can immediately relieve menstrual pain and minimize the influence of pain on daily life compared with GB39 and an adjacent non-meridian point. The data preliminarily show the specificity of SP6 for the immediate pain relief of primary dysmenorrhea.