NCT06550115 · Colorado State University
Impact of Circulating and Tissue-specific Lipids on Vascular Function and Insulin Sensitivity in Chronic Night Shift Workers
(SHINE)
What this study is about
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.
View original scientific description
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.
Interventions
BEHAVIORAL
Time-restricted eating
Night shift workers will participate in 4 weeks of fasting during the biological nighttime while remaining awake during overnight work shifts.
BEHAVIORAL
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 measures
Blood pressure via 24-hour assessments
Time frame: Collected during inpatient laboratory visit after 4 weeks of Control and TRE
Four weeks of TRE during shift work will reduce 24-hour blood pressure versus Control.
Insulin sensitivity via clamp
Time frame: Collected during inpatient laboratory visit after 4 weeks of Control and TRE
Four weeks of TRE during shift work will improve insulin sensitivity versus Control.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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.
Where
- Fort Collins, Colorado
Collaborators
University of Colorado, Denver, National Heart, Lung, and Blood Institute (NHLBI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 17, 2025 · Source of record for eligibility and locations