Sleep Loss and Circadian Misalignment - Mechanisms of Insulin Resistance

Conditions

• Circadian Misalignment
• Circadian Rhythm
• Insulin Resistance
• Shift Work Schedule

Eligibility Criteria

Sex

ALL

Age

18 Years - 45 Years

Healthy Volunteers

Accepted

Interventions

• Metyrapone And Hydrocortisone — DRUG
  Cortisol will be clamped with oral administration of Metyrapone, which blocks endogenous cortisol biosynthesis. A loading dose of 3,000mg will be given at 10:00 on day 2. Every 4 hours throughout the sleep restriction and sleep deprivation phases, 500mg will be administered beginning at 14:00 on day 2 and ending with a dose at 18:00 on day 5. Using a subcutaneous pump, hydrocortisone is administered here as physiological replacement, with pulses every 3 hours beginning at 10:00 on day 2. Participants will receive 3 tiers of doses: low (0.5mg), moderate (2.3mg) and high (4.0mg), the timing of which is specified by their condition assignment. For all participants, an oral 25mg dose of hydrocortisone will be given at the end of the constant routine period to prevent any future hypocortisolemia associated with the hormone clamp.
• Dextrose — DRUG
  The frequently sampled intravenous glucose tolerance test is performed before and after sleep restriction, and is widely used and validated. This procedure requires intravenous administration of dextrose, 300 mg/kg as a bolus at time zero. Insulin (0.03 units/kg/min) will be slowly infused intravenously over a 5 minute period from 20 to 25 minutes. Few side effects are anticipated as both doses of glucose and insulin should result in a high, but physiological peak. Administration of insulin as 5-min infusion for clinical studies (rather than bolus) reduces the max concentrations achieved. It is not uncommon for glucose to dip below fasting glycemia at some point after the insulin administration. The concentration at the nadir depends on the subject's insulin sensitivity. Return to fasting level is a function of the waning of the insulin effect (incorporated into the minimal model) as well as counterregulation (which depends on the concentration at the nadir). This can be addressed,
• insulin — DRUG
  The frequently sampled intravenous glucose tolerance test is performed before and after sleep restriction, and is widely used and validated. This procedure requires intravenous administration of dextrose, 300 mg/kg as a bolus at time zero. Insulin (0.03 units/kg/min) will be slowly infused intravenously over a 5 minute period from 20 to 25 minutes. Few side effects are anticipated as both doses of glucose and insulin should result in a high, but physiological peak. Administration of insulin as 5-min infusion for clinical studies (rather than bolus) reduces the max concentrations achieved. It is not uncommon for glucose to dip below fasting glycemia at some point after the insulin administration. The concentration at the nadir depends on the subject's insulin sensitivity. Return to fasting level is a function of the waning of the insulin effect (incorporated into the minimal model) as well as counterregulation (which depends on the concentration at the nadir). This can be addressed,

Study Details

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.

Key Dates

Start date

Jul 1, 2026

Status verified

May 2026

Primary completion

Mar 31, 2029

Completion

Jul 31, 2029

Study Design

Enrollment

48 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

DIAGNOSTIC

Arms

• Active Comparator: Misaligned cortisol rhythm-night shift condition
  Cortisol will be clamped with oral administration of Metyrapone, which blocks endogenous cortisol biosynthesis. A loading dose of 3,000mg will be given at 10:00 on day 2. Every 4 hours throughout the sleep restriction and sleep deprivation phases, 500mg will be administered beginning at 14:00 on day 2 and ending with a dose at 18:00 on day 5. Using a subcutaneous pump, hydrocortisone is administered here as physiological replacement, with pulses every 3 hours beginning at 10:00 on day 2. Participants assigned to the misaligned cortisol rhythm condition will receive: lowest doses (0.5mg) at 22:00 and 01:00; moderate doses (2.3mg) at 13:00, 16:00, and 19:00; and highest doses (4.0mg) at 04:00, 07:00, and 10:00. An oral 25mg dose of hydrocortisone will be given at the end of the constant routine period to prevent any future hypocortisolemia associated with the hormone clamp.
• Active Comparator: Realigned cortisol rhythm-night shift condition
  Cortisol will be clamped with oral administration of Metyrapone, which blocks endogenous cortisol biosynthesis. A loading dose of 3,000mg will be given at 10:00 on day 2. Every 4 hours throughout the sleep restriction and sleep deprivation phases. Participants will receive their doses at a 12-hour offset from the misaligned condition, with: lowest doses (0.5mg) at 10:00 and 13:00; moderate doses (2.3mg) at 01:00, 04:00, and 07:00; and highest doses (4.0mg) at 16:00, 19:00, and 22:00. The last subcutaneous dose will be administered at 19:00 on day 5. An oral 25mg dose of hydrocortisone will be given at the end of the constant routine period to prevent any future hypocortisolemia associated with the hormone clamp.
• Active Comparator: Fixed cortisol shape condition- day shift condition
  Cortisol will be clamped with oral administration of Metyrapone, which blocks endogenous cortisol biosynthesis. A loading dose of 3,000mg will be given at 10:00 on day 2. Every 4 hours throughout the sleep restriction and sleep deprivation phases, 500mg will be administered beginning at 14:00 on day 2 and ending with a dose at 06:00 on day 5. Using a subcutaneous pump, hydrocortisone is administered here as physiological replacement, with pulses every 3 hours beginning at 10:00 on day 2. Participants assigned to the fixed cortisol shape condition will receive: lowest doses (0.5mg) at 22:00 and 01:00; moderate doses (2.3mg) at 13:00, 16:00, and 19:00; and highest doses (4.0mg) at 04:00, 07:00, and 10:00. The last subcutaneous dose will be administered at 07:00 on day 5. An oral 25mg dose of hydrocortisone will be given at the end of the constant routine period to prevent any future hypocortisolemia associated with the hormone clamp.
• Placebo Comparator: Unfixed cortisol shape condition-day shift condition
  Participants will receive a metyrapone placebo at times matching the doses in Condition A (i.e., at 10:00 on day 2 and continuing every 4 hours until 06:00 on day 5). Using a subcutaneous pump, placebo hydrocortisone is administered matching the doses in Condition A (i.e., with pulses every 3 hours beginning at 10:00 on day 2 until 07:00 on day 5). A placebo matching the oral hydrocortisone will be administered at 10:00 on day 5.

Primary Outcome Measure

Insulin resistance-Minimal Model (Si) [ Time Frame: Change from baseline collection. ]

Central Contacts

• Devon A Hansen, PhD
  509-358-7754
  [email protected]
• Olivia Brooks, MS
  509-358-7904
  [email protected]

Locations (1)

Find similar trials in Spokane, WA

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