Recruiting

Observational Study

Sponsor:

Colorado State University

Code:

NCT06550115

Conditions

Circadian Rhythm Sleep Disorder of Shift Work Type

Metabolic Disease

Insulin Sensitivity

Blood Pressure

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Interventions

Time-restricted eating

Control eating

Study Details

Brief summary:

People who experience repeated bouts of circadian misalignment, such as shift workers, are at higher risk of cardiovascular disease (CVD) and Type 2 diabetes (T2D) compared to daytime workers. However, the mechanism(s) by which shift work and associated circadian misalignment increase CVD and T2D risk are unknown. This project will examine whether elevated plasma lipids are a mechanism by which circadian misalignment impairs vascular function, insulin sensitivity, glucose homeostasis and muscle lipid accumulation, which could be targeted to prevent and treat cardiometabolic disease in people who chronically experience circadian misalignment, which includes more than 20% of the US workforce.

Conditions

Circadian Rhythm Sleep Disorder of Shift Work Type

Metabolic Disease

Insulin Sensitivity

Blood Pressure

Study ID

NCT06550115

Start date

Mar 1, 2024

Status verified date

Dec, 2025

Completion date

Jun, 2029

Anticipated

Primary completion date

Jun, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 18-65 years old
  • worked the night shift for the last 1 year or more,
  • habitually sleep 5-9 hours per 24h period (night shift workers typically experience chronic insufficient sleep),
  • body mass index (BMI) of 20.0 - 35.0 kg/m2 and weight stable (plus or minus 5% of current body weight in the last 6 months); sedentary to mild physical activity level (less than 2 days of planned exercise per week);

Exclusion Criteria:

  • existing diagnosed sleep or eating disorder (e.g. obstructive sleep apnea \[OSA\], periodic limb movements of sleep \[PLMS\], narcolepsy, travel more than 1 time zone in 3 weeks before the study; anorexia nervosa, more than one food allergy to maintain flexibility in diet planning);
  • following any TRE (time-restricted eating) or intermittent fasting plan in the last year;
  • following any special diet plan, like paleo, keto, gluten-free or vegan, that can affect the primary lipid outcome measures in the last 6 months; any clinically significant surgical condition within the last year;
  • diagnosed diabetes or cardiovascular disease

  • The prevalence of insomnia in shift workers is fairly high, ranging from 12.8% to 76.4%, which is higher than estimated for the general population. Insomnia itself is associated with elevated neural cardiovascular responsiveness to stress compared to people without insomnia. Thus, since excessive sleepiness and symptoms of insomnia may be present in night shift workers they will not be exclusionary.

Study Design

Enrollment

50 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Control eating during overnight work shift

For 4 weeks, participants will eat during the biological night as is typically done in night shift workers.

experimental: Time-restricted eating during overnight work shift

For 4 weeks, participants will refrain from eating during the biological night while maintaining the same sleep opportunity and daily energy intake and macronutrient distribution without changing 24h energy intake.

Interventions

Time-restricted eating

Night shift workers will participate in 4 weeks of fasting during the biological nighttime while remaining awake during overnight work shifts.

Control eating

Night shift workers will participate in 4 weeks of Control eating across the daytime and nighttime hours while remaining awake during overnight work shifts.

Primary outcome measure

  • Blood pressure via 24-hour assessments [ Time Frame: Collected during inpatient laboratory visit after 4 weeks of Control and TRE ]
  • Insulin sensitivity via clamp [ Time Frame: Collected during inpatient laboratory visit after 4 weeks of Control and TRE ]

Central Contacts and Locations

Central contacts

Josiane L Broussard, PhD

9704913103josiane.broussard@colostate.edu

Ellen Lyon, MS

9704913103ellen.lyon@colostate.edu

Locations

Colorado State University

Recruiting

Fort Collins, Colorado, United States, 80523

Contacts

Ellen Lyon, MS

970-491-3103ellen.lyon@colostate.edu

Principal Investigator:

Josiane L Broussard, PhD

More Information

Sponsor

Colorado State University

Last update posted

Dec 17, 2025

Last verified

Dec, 2025

Keywords

  • Shift work
  • Sleep
  • Blood sugar
  • Metabolism
  • Lipids
  • Blood pressure

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Colorado State University on 2025-12-17.