Impact of Menstrual Cycle Phase on Metabolic Effects of Sleep Restriction

Abstract

The effects of one night of 3h sleep on cortisol levels were assessed in two groups of women at different points in their menstrual cycles: mid-follicular and mid-luteal. Eighteen women (age: 21.8 ± 0.54; BMI: 22.6 ± 0.63, mean ± SEM) were studied. Salivary samples were collected at six times during two consecutive days: first after a 10 h overnight sleep opportunity and then after a night with a 3 h sleep opportunity. Secondary analysis examined the impact of sleep restriction on self-reports of hunger ratings and mood. Women in the follicular phase showed a significant decrease (p =0.004) in their cortisol awakening responses after sleep restriction and an elevation in afternoon/evening cortisol levels (p =0.008), whereas women in the luteal phase showed no change. Overall group increases in hunger and deterioration in fatigue and vigour were observed. Menstrual cycle phase dramatically altered the responses of women to a single night of sleep restriction.