Effect of acupuncture on heart rate variability in primary dysmenorrheic women

Primary dysmenorrhea is a common gynecological complaint among young women which is related to an autonomic nervous system (ANS) disturbance. Acupuncture is one of several therapeutic approaches for primary dysmenorrhea since it can modulate ANS function. The heart rate variability (HRV) parameters such as high frequency (HF), low frequency (LF) and LF/HF ratio are generally accepted tools to assess ANS activity. The purpose of this study was to investigate the effects of acupuncture applied at Hegu (LI4) and Sanyinjiao (SP6) points on HRV of women with primary dysmenorrhea during the late luteal phase. The experimental design was a crossover and patient-blinded procedure. All subjects participated in Sham (SA) and Real Acupuncture (RA) procedure, separated by one month, in a crossover sequence. The participants included 38 women (mean age 22.3 years; weight 53.8 kg; height 162.6 cm). HRV measurement was for 15 min before and after an acupuncture procedure. The RA procedure was performed at two bilateral acupoints, but needles were inserted subcutaneously to the acupuncture points for the SA procedure. The RA induced a significant decrease in LF/HF ratio and a significant increase in the HF power, while SA treatment caused a significant increase only in the HF power. Manual acupuncture at bilateral acupoints of LI4 and SP6 may play a role in dysmenorrhea treatment with autonomic nervous system involvement.