The Healthy Heroes Study

Study Overview
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Brief Summary
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This is the first study of its kind to assess and test an intervention to improve biological rhythms and general health of shift workers, specifically first responders with San Diego Fire and Rescue. In a randomized control trial, investigators intend to measure the health impact of Time Restricted Eating in emergency responders who work a 24-hour shift schedule.

Detailed Description
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Participants will be randomly assigned to a control group of behavioral nutrition counseling (standard of care) or the intervention group of standard of care with the addition of adopting a 10 hour eating window for one year (TRE). For the first 3 months of intervention, participants will be monitored closely by the research team. For the following 9 months, participants will be in a self-monitored intervention period. Investigators will evaluate the impact of TRE on blood glucose levels, biomarkers, sleep/mood, and weight loss. These assessments will be made at baseline, at the end of the 12-week monitored intervention period, and every 3 months (months 6, 9, and 12) during the self-monitored intervention period for one year. Food/drink intake, activity, and sleep will be monitored with the smartphone myCircadianClock application (mCC app) throughout the study. A continuous glucose monitor, a wrist-worn actigraphy device, and questionnaires will also be used during the study.

Official Title
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Optimizing Circadian Rhythms by Regulating Eating Patterns to Reduce Cardiometabolic Disease Risk Among Firefighters--The Healthy Heroes Study

Conditions
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Fasting, Shift Workers' Health, Time Restricted Eating

Intervention / Treatment
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* Behavioral: Time Restricted Eating + Standard of Care
* Behavioral: Standard of Care


Participation Criteria
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Eligibility Criteria
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As per recommendations from the fire department, fire department unions, and funding agencies, we did not require compromised health measures (e.g. hyperglycemia, hypertension, etc.) as inclusion criteria for they would be discriminatory against some firefighters. Inclusion Criteria: Firefighter or work a 24-hr shift schedule with San Diego Fire and Rescue Age: 21-65 years Own a smartphone (Apple or Android Operating System) If participants are on cardiovascular medications (HMG-CoA reductase inhibitors (statins), other lipid modifying drugs (including over the counter drugs such as red yeast rice and fish oil), anti-hypertensive, anti-diabetes drugs), no dose adjustments will be allowed during the study period Exclusion Criteria: Insulin-dependent diabetes mellitus Presence of acute chronic inflammatory or autoimmune disease (defined by acute symptoms or C-reactive protein >10 mg/L), malabsorption syndromes, liver disease, or kidney disease (stage 3 or greater) Uncontrolled thyroid disease Intake of drugs likely to interfere with study endpoints, including corticosteroids, anabolic steroids, anti-psychotics, antiretroviral drugs, and immunosuppressive drugs (within 3 months of starting the study) Presence or recent history of anemia (hematocrit <33% within 3 months of starting the study) History of bariatric surgery Pregnant or breast-feeding women Current or recent (within 12 months of starting the study) pregnancy or breastfeeding, or intention of becoming pregnant in the next 6 months Any cancer other than non-melanoma skin cancer in the last 3 years On a special or prescribed diet for other reasons (e.g. Celiac disease) Depression determined by the Beck Depression Inventory (BDI) Planned international travel during study period Insufficient logging on the mCC app (does not log at least 2 entries a day for 10 of 14 days) during baseline will exclude from being randomized into the intervention period

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: TRE + SOC<br>Time Restricted Eating + Standard of Care | Behavioral: Time Restricted Eating + Standard of Care<br>* Participants in this arm will adhere to a daily, consistent 10-hr eating window for the course of the study as well as receive nutritional counseling from the study dietician.<br>* Other names: Time Restricted Eating;|
| Other: SOC<br>Standard of Care | Behavioral: Standard of Care<br>* Participants in this arm will receive nutritional counseling from the study dietician, but will not be required to adopt a 10-hr eating window.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the impact of TRE on glucose homeostasis at end of intervention compared to baseline | Measured by an ambulatory continuous glucose monitoring device and blood work throughout the study. Note: Significant changes expected in participants who had elevated glucose homeostasis at baseline. No significant changes expected in those within normal ranges at baseline. Primary endpoint analysis will be done by comparing baseline and 12-week intervention. | primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 
| Assess the feasibility and adherence of TRE | Measured by percentage of days logged that participants ate within their 10-hour window and by end of study responses. Note: Significant changes expected in participants in the TRE arm of the study on and off shift. No significant changes expected in the standard of care arm of the study. Primary endpoint analysis will be done by comparing baseline and 12-week intervention. | primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess changes in metabolic biomarkers in response to TRE at end of intervention compared to baseline | Measured with blood biochemistry.Measured with blood biochemistry under TRE, including, but not limited to: fasting glucose, HbA1c, cholesterol, and triglycerides. Note: Significant changes expected in participants who had abnormal levels at baseline (e.g. elevated LDL cholesterol, low HDL cholesterol, elevated triglycerides). No significant changes expected in those were within normal ranges at baseline. | Timeframe: primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 
| Systolic blood pressure (mmHg) in response to TRE at end of intervention compared to baseline | Measured at baseline and during TRE intervention. Note: Significant changes expected in participants who had elevated systolic blood pressure at baseline. No significant changes expected in those without elevated systolic blood pressure at baseline. | Timeframe: primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 
| Diastolic blood pressure (mmHg) in response to TRE at end of intervention compared to baseline | Measured at baseline and during TRE intervention. Note: Significant changes expected in participants who had elevated diastolic blood pressure at baseline. No significant changes expected in those without elevated diastolic blood pressure at baseline. | primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 
| Body weight (kg) | Measured on a digital scale. Note: Significant changes expected in participants who had elevated weight at baseline. No significant changes expected in those who were not overweight at baseline. | primary endpoint=12-week intervention (compared to 2-week baseline); follow-up will be at 1-year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Shift Workers, Time-Restricted Eating, Fasting, Firefighters, San Diego Fire and Rescue, Cardiometabolic Health, First Responder