The Effects of Night Shift Work on Health Across the Menstrual Cycle

Primary outcomes

1. The effect of sleep deprivation vs sleep on brain health across the menstrual cycle

   Time frame: 1 year

   Blood analysis for neurodegenerative biomarkers, specifically Tau protein phosphorylated at amino acid 181 and 231, Aβ40 and Aβ42, GFAP, NfL.

2. The effects of sleep deprivation across the menstrual cycle on EEG

   Time frame: 1 year

   The Dreem headband will be used to record EEG, assessing wakefulness levels during the sleep deprivation night through spectral power analysis. It will also be used to generate a hypnogram for sleep stage classification.

3. The effects of sleep deprivation on metabolic function (TEE)

   Time frame: 2 years

   Energy Expenditure is measured with the K5 wearable system to monitor VO₂ and VCO₂ in real-time, assessing total energy expenditure (TEE).

4. The effects of sleep deprivation on glucose metabolism

   Time frame: 1 year

   Assessed with an Oral Glucose Tolerance Test (OGTT) and continuous blood glucose monitoring.

5. The effects of sleep deprivation on leptin/adiponectin ratio

   Time frame: 2 years

   Blood analysis to assess the ratio of leptin/adiponectin for metabolic health throughout the menstrual cycle.

6. The effects of sleep deprivation on vaginal microbiota identification across the menstrual cycle

   Time frame: 2 years

   Identification and comparison of bacterial species composition and diversity (alpha- and beta-diversity)

7. The effects of sleep deprivation on vaginal microbiota classification across the menstrual cycle

   Time frame: 2 years

   Classification of community state types (CST)

8. The effects of sleep deprivation on vaginal microbiota across the menstrual cycle

   Time frame: 2 years

   Changes in total phage content

9. The effect of sleep deprivation on stress response across the menstrual cycle

   Time frame: 2 years

   An auditory paradigm for stress induction will employ eye tracking to monitor changes in pupil dilation.

10. The effect of sleep deprivation on stress response across the menstrual cycle

    Time frame: 2 years

    Galvanic skin response measures the electrical characteristics or conductance of the skin as an indirect measure of sympathetic autonomic activity using the change of electrical properties of skin measured continuously throughout an auditory paradigm designed to induce stress.

11. The effect of sleep deprivation on stress response across the menstrual cycle

    Time frame: 2 years

    Heart rate is tracked to assess autonomic responses to stress throughout the auditory paradigm for stress induction.

12. The effects of sleep deprivation on immune system profiling across menstrual cycle

    Time frame: 3 years

    Human blood samples are analyzed to determine the levels of proangiogenic neutrophils characterized as CD45+CD3-CD19-CD16+CD49d+VEGFR1+. Additionally, the presence of cytotoxic natural killer (NK) cells defined as CD56dim, CD16+, CX3CR1+, CCR7-, CXCR4dim, and CD57+, alongside non-cytotoxic NK cells, which are identified as CD56bright, CD16-, CX3CR1-, CCR7+, CXCR4 high, and CD57-. The cellular populations are expressed as a percentage of CD45+ positive cells, reflecting the total leukocyte population in the blood. To quantify these cell types, the leukocytes are isolated through gradient centrifugation and analyzed using spectral flow cytometry following incubation with two multicolor antibody panels.

    The technique used is FACS, fluorescence-activated cell sorting.

13. The levels of 6-sulfatoxymelatonin across the menstrual cycle during sleep and sleep deprivation conditions

    Time frame: 2 years

    Urine levels measured 6-sulfatoxymelatonin during both sleep and sleep deprivation condition

14. The effects of sleep vs sleep deprivation on ABI across the menstrual cycle

    Time frame: 1 year

    Ankle-Brachial Index (ABI) assessed by comparing blood pressure in legs and arms.

15. The effects of sleep deprivation on palatability across the menstrual cycle

    Time frame: 2 years

    Subjective rating of palatability for food items on a Visual Analogue Scale (VAS).

    Scale Range: 0 to 100, with 0 indicating "not at all palatable" and 100 indicating "extremely palatable." Higher scores indicate greater palatability, potentially signaling increased appeal for certain foods/calories following sleep deprivation, typically viewed as an adverse outcome.

16. The effects of sleep deprivation on appetite across the menstrual cycle

    Time frame: 2 years

    Blood analysis for leptin/ghrelin ratio

17. The effects of sleep deprivation on food arousal across the menstrual cycle

    Time frame: 2 years

    Food arousal response will be assessed using an eye tracker to analyze changes in pupil dilation.

18. The effects of sleep deprivation on hunger across the menstrual cycle

    Time frame: 2 years

    A portion size task is administered to the participant on the morning following both sleep and sleep deprivation conditions to assess hunger. Hunger will be measured by the total caloric content of food portions selected by the participant during the task.

19. The effects of sleep deprivation on psychomotor vigilance across the menstrual cycle

    Time frame: 2 years

    The Psychomotor Vigilance Task (PVT) is a visual reaction time test used to objectively assess sustained attention and alertness. Participants respond as quickly as possible to visual stimuli, with mean reaction time and the number of lapses (missed responses) serving as key outcome measures that reflect cognitive performance, particularly in conditions like sleep deprivation or fatigue.

20. The effect of salivary cortisol on sleep vs sleep deprivation across the menstrual cycle

    Time frame: 2 years

    Salivary cortisol samples will be collected during the sleep deprivation night and on the following morning after both sleep and sleep deprivation conditions to investigate cortisol levels in response to sleep loss across menstrual cycle.

21. Oral microbiota changes across menstrual cycle and sleep deprivation

    Time frame: 4 years

    Analyze the changes in the oral microbiota across the menstrual cycle in sleep and sleep deprivation conditions by investigating shifts in microbial composition, diversity, and the abundance of bacteria. This could provide insights into how sleep patterns and menstrual phases interact to impact oral health.