Objective: To observe the therapeutic effect of ear-electroacupuncture (Ear-EA) on dysmenorrhea in patients with endometriosis and to explore its underlying mechanism.
Methods: A total of 80 endometriosis patients were randomly and equally divided into ear-EA group and body-EA group. EA (50 Hz, 0.5-0.8 mA) was applied to auricular points (Uterus, Subcortex, Shenmen, Endocrine, etc.) and body acupoints [Tianshu (ST 25), Qihai (CV 6), Guanyuan (CV 4), Sanyinjiao (SP 6), Diji (SP 8), Uterus (EX-CA 1), etc.] respectively for 30 min, once every other day for 3 months. Dysmenorrhea severity score (DSS) was assessed and plasma prostaglandin (PGE2) and 6-Keto-PGF1alpha levels detected by radioimmunoassay.
Results: Compared with pre-treatment, DSS lowered significantly during the 1st and 2nd menstrual cycle in body-EA group, and during the 1st, 2nd and 3rd menstruation in ear-EA group; and the DSS of ear-EA group during the 3rd menstruation was evidently lower than that of body-EA group (P < 0.05). During the 3rd menstrual onset after the treatment, plasma PGE2 contents in both groups decreased obviously (P < 0.01), and plasma 6-Keto-PGF1alpha, levels increased considerably in comparison with pre-treatment (P < 0.01). Comparison between two groups during the 3rd menstruation showed that plasma PGE2 level of ear-EA group was markedly lower than that of body-EA group, and 6-Keto-PGF1alpha, level of ear-EA group was significantly higher than that of body-EA group (P < 0.05). No significant difference was found between two groups in clinical therapeutic effect (P > 0.05).
Conclusion: Both ear-EA and body-EA can effectively relieve endometriosis-induced dysmenorrhea, and the former is superior to the later in reducing pain severity, which may be closely related to their effects in reducing plasma PGE2 and raising 6-Keto-PGF1alpha level.