RightFit
RecruitingPhase 4

Sleep Loss and Circadian Misalignment - Mechanisms of Insulin Resistance

Who can join

As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.

Age
18 Years to 45 Years
Sex
All sexes
Healthy volunteers
Accepted
Compensation
Not stated

Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.

What to expect

No one can promise a trial will help you personally — that is what the research is trying to find out.

What participation involves

Not stated in the study description — ask the study team about visits and procedures.

Compensation
Not stated
  • Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
  • Participants are monitored closely by the research team throughout the study.
  • Some participants may receive access to an investigational treatment, which is still being studied.
  • Your participation helps researchers learn whether this approach could help future patients.

About this study

In plain language

This study tests how the timing of cortisol, a stress hormone, affects how well insulin works when people get less sleep. Insulin helps control blood sugar. The study is for healthy men and women ages 18–45.

The purpose of this study is to examine the impact of timed cortisol release or differently timed cortisol rhythms on insulin resistance in both men and women undergoing sleep restriction. Chronic sleep loss is highly prevalent, affecting 1 in 3 adults in the US. Chronic sleep loss causes stress which induces insulin resistance and leads to obesity and type 2 diabetes. Many factors contribute to sleep loss including shift work, environmental disturbances, sleep/circadian disorders and comorbid medical and mental health conditions. Sleep loss increases the stress hormone cortisol in the evening and decreases daytime testosterone. Examining these hormones in a controlled laboratory environment under different sleep schedules may help researchers find solutions for adults experiencing negative health consequences related to chronic sleep loss.

Compensation is read from the study's own description and may be missing — always confirm with the study team.

Eligibility

Who can join

  • Be age 18–45, with a BMI of 18–25. BMI is a measure of weight compared with height. Your weight must have stayed steady for 6 weeks.
  • Be in good physical and mental health, with no hormone disorders or anemia (too few red blood cells).
  • Women must have regular periods and a negative pregnancy test. Study visits must take place during the part of the cycle before an egg is released.
  • Take no medicines or medical treatments, including steroids, hormones, or hormonal birth control.
  • Have blood and urine tests with no major health concerns or signs of drug use. Have no history of drug or alcohol abuse, and do not currently smoke.
  • Usually sleep 6–10 hours with regular bedtimes. Have no sleep or body-clock disorder, and not be an extreme early bird or night owl.
  • Have done no shift work in 3 months and no travel across time zones in 1 month. Have had no bad reactions to sleep loss, jet lag, shift work, or the study drugs.
  • Have donated no blood in 8 weeks and not be in another research study.

Who can't join

    Simplified for readability. The official criteria below are what the study team uses.

    Official eligibility criteria

    Inclusion Criteria: 1. Must be between 18-45 years old. 2. Has a BMI of 18-25 kg/m2 stable weight over the previous 6 weeks. 3. Is physically and psychologically healthy (incl. regular menstrual cycles in women, no clinical disorders and/or illnesses). Women will be studied during the follicular phase of their menstrual cycle. Menstrual cycle criteria (using PMID 10941950) 18 to 25 years - Cycle variation ≤9 days 26 to 41 years - Cycle variation ≤7 days 42 to 45 years - Cycle variation ≤9 days 4. No current medical or drug treatment (to include steroids or hormones of any type including contraceptives), as assessed by questionnaire. 5. Has a negative pregnancy test (women), no clinically significant abnormalities in blood and urine, and free of traces of drugs. 6. No history of clinically relevant psychiatric illness. 7. No previous history of drug or alcohol abuse. 8. Not a current smoker. 9. No history of brain injury or of learning disability. 10. No previous adverse reaction to sleep deprivation, jet lag, shift work or any of the drugs to be administered. 11. Not vision or hearing impairment unless corrected back to normal. 12. No endocrine disorder (no abnormal thyroid function tests; no abnormal morning blood cortisol; no primary gonadal disease as indicated by serum LH or FSH concentration \> 10 or \> 15 IU/L, respectively; and no hyperprolactinemia indicated by prolactin \> 25 μg/L). 13. No sleep or circadian disorder. 14. Has good habitual sleep with regular bedtimes (between 6 and 10 hours in duration). 15. Not extreme morning- nor extreme evening-type using Horne-Ostberg Morningness-Eveningness criteria. 16. No travel across time zones within one month of entering the study. 17. No shift work within three months of entering the study. 18. No anemia (hematocrit \<38% in men, \<34% in women). 19. No blood donation within the previous 8 weeks. 20. No concurrent participation in another research study.

    Study sites (1)

    WA