Abstract
Purpose: Bright light therapy has favorable effects on treating patients with seasonal affective disorder, sleep disturbance, or premenstrual disorder (PMD) with the. In this study, we observed the effects of light therapy to the autonomic nervous system throughout the menstrual periods to investigate the possibility to apply for PMD treatment.Methods: The study consists of 6 college female students (age 21±1 years old) without PMD. ECG was recorded for 24 hours during the follicular and luteal phases of the menstrual cycles. The responses to the lightening of white light emitting diode (LED) were observed in each phase of menstration. The R-R variabilities were analyzed by MEMCALC methods in order to observe the changes of the autonomic nervous activities.Results: The power of high frequency (HF) component was lower during luteal phase and higher in the follicular phase, while low frequency/high frequency (LF/HF) ratio was lower in the follicular phase and higher in the luteal phase. The light therapy enhanced the fluctuation of LF/HF ratio during luteal phase, compared to that during follicular phase.Conclusion: During luteal phase, sympathetic nerve activities (LF/HF) was higher, and the fluctuation was exaggerated by the exposure to the white LED. These data suggest that autonomic nervous activities would be affected by the menstrual cycle, and the exposure to white LED.
