A pilot study of light exposure as a countermeasure for menstrual phase-dependent neurobehavioral performance impairment in women

Leilah K. Grant, Joshua J. Gooley, Melissa A. St. Hilaire, Hadine Joffe, George C. Brainard, Eliza Van Reen, Melanie Rüger, Shantha M.W. Rajaratnam, Steven W. Lockley, Charles A. Czeisler, Shadab A. Rahman

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)

Abstract

Objective: To examine effects of menstrual phase and nighttime light exposure on subjective sleepiness and auditory Psychomotor Vigilance Task performance. Methods: Twenty-nine premenopausal women (12 = Follicular; 17 = Luteal) completed a 6.5-hour nighttime monochromatic light exposure with varying wavelengths (420-620 nm) and irradiances (1.03-14.12 µW/cm2). Subjective sleepiness, reaction time, and attentional lapses were compared between menstrual phases in women with minimal (<33%) or substantial (≥33%) light-induced melatonin suppression. Results: When melatonin was not suppressed, women in the follicular phase had significantly worse reaction time (mean difference = 145.1 ms, 95% CI 51.8-238.3, p <.001, Cohen's D = 1.9) and lapses (mean difference = 12.9 lapses, 95% CI 4.37-21.41, p <.001, Cohen's D = 1.7) compared to women in the luteal phase. When melatonin was suppressed, women in the follicular phase had significantly better reaction time (mean difference = 152.1 ms, 95% CI 43.88-260.3, p <.001, Cohen's D = 1.7) and lapses (mean difference = 12.3 lapses, 95% CI 1.14-25.6, p <.01, Cohen's D = 1.6) compared to when melatonin was not suppressed, such that their performance was not different (p >.9) from women in the luteal phase. Subjective sleepiness did not differ by menstrual phase (mean difference = 0.6, p >.08) or melatonin suppression (mean difference = 0.2, p >.4). Conclusions: Nighttime light exposure sufficient to suppress melatonin can also mitigate neurobehavioral performance deficits associated with the follicular phase. Despite the relatively small sample size, these data suggest that nighttime light may be a valuable strategy to help reduce errors and accidents in female shift workers.

Original languageEnglish
Pages (from-to)S34-S40
Number of pages7
JournalSleep Health
Volume10
Issue number1S
DOIs
Publication statusPublished - Feb 2024
Externally publishedYes

Keywords

  • Light
  • Melatonin
  • Menstrual phase
  • Neurobehavioral performance
  • Night work
  • Shift work
  • Women

Cite this