Circadian Intervention to Improve Cardiometabolic Health (TOCS)

Timing of Circadian Synchronizers: the TOCS Study

The overall goal is to examine the efficacy of a circadian intervention in people with overweight and obesity and habitual short sleep duration (HSSD). Participants will undergo a randomized controlled trial, with circadian intervention and control (healthy lifestyle) groups. The circadian intervention is designed to reduce nighttime light exposure and after-dinner snack food intake. Alternatively, the control group will receive basic health information (e.g., physical activity, goal setting, and nutrition when eating out).

Study Overview

• Status: Recruiting
• Conditions: Sleep; Type 2 Diabetes; Overweight and Obesity; Insulin Sensitivity; Time Restricted Feeding; Sleep Hygiene; Cardiometabolic Syndrome; Eating Habit; Lifestyle Factors
• Intervention / Treatment: Behavioral: Circadian Intervention

Detailed Description

The study is a randomized controlled trial with control and circadian intervention groups. Group allocation will be blinded to research staff and participants until the conclusion of the baseline segment. The circadian intervention group will receive counseling and instruction to reduce evening and nighttime light exposure, increase morning room light and sunlight exposure, and complete all food consumption at least 4 hours before bedtime. Participants randomized to control will maintain their habitual food intake and sleep habits in their home environment for ~8 weeks. Both groups will have equal contact time with the study team.

Prior to enrollment participants will complete an clinical overnight sleep disorders screening. Baseline consists of an ~1-week ambulatory real-world monitoring segment. Following baseline participants will be randomized to the control or intervention groups for the 8 week experimental segment. Throughout the study sleep duration will be monitored using an actiwatch wrist-device and a daily electronic sleep log. At the end of the baseline and experimental segments participants will complete overnight laboratory visits to assess insulin sensitivity and circadian timing by oral glucose tolerance test and dim light melatonin onset, respectively.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christopher M Depner, PhD; Phone Number: 801-581-2275; Email: christopher.depner@utah.edu

Study Locations

• United States
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • Recruiting
      • College of Health Research Complex--University of Utah
      • Contact: Christopher Depner; Phone Number: 8015812275; Email: sleepstudyparticipant@utah.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Age: 18-45 years old; equal numbers of men and women
2. Body mass index (BMI): 25.0-34.9 kg/m2,
3. Sleep Habits: habitual self-reported average total sleep time (TST) <6.5 hours per night for prior 6 months

Exclusion Criteria:

1. Clinically diagnosed sleep disorder or major psychiatric illness
2. Evidence of significant organ dysfunction or disease (e.g., diagnosed diabetes, cardiovascular disease, or kidney disease)
3. Use of prescription drugs or substances known to influence sleep or glucose metabolism
4. Shift-work: current or history of within last year
5. Weight change: >10% of body weight over prior six months
6. Experiencing menopause or post-menopausal
7. Current enrollment in weight loss or physical activity program like the Diabetes Prevention Program
8. Currently pregnant or planning to become pregnant, or currently lactating.
9. Currently smoking
10. Alcohol intake >3 drinks per day or >14 drinks per week

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control Group; Provided with general health information on diet and physical activity.
Experimental: Intervention Group; Circadian-based intervention focused on timing of light exposure and food intake.	Behavioral: Circadian Intervention; The circadian intervention group will receive counseling and instruction to reduce evening and nighttime light exposure, increase morning room light and sunlight exposure, and to finish all food consumption at least 4 hours before bedtime.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin sensitivity change from baseline	Oral Glucose Tolerance Test (OGTT), Matsuda Index	Change from baseline to end of the ~8 week experimental segment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Timing of central circadian clock change from baseline	Quantified as dim-light melatonin onset from salivary melatonin samples	Change from baseline to end of the ~8 week experimental segment
Plasma ceramides change from baseline	Fasting plasma samples will be analyzed for plasma ceramides using targeted metabolomics	Change from baseline to end of the ~8 week experimental segment
Average (per week) nightly total sleep time change from baseline	Analyzed by wrist-actigraphy	Analyzed as change from baseline for each week of the ~8 week experimental segment
Average (per week) sleep satisfaction change from baseline	5 point likert scale on daily sleep log (1 = very good; 5 = very poor)	Analyzed as change from baseline for each week of the ~8 week experimental segment
Average (per week) self-reported sleep duration change from baseline	Daily electronic sleep logs will be used to track sleep and waketimes during the ambulatory monitoring phases of the study	Analyzed as change from baseline for each week of the ~8 week experimental segment
Average (per week) timing of food intake change from baseline	Time of day 50% of calories are consumed collected by picture based food diaries. Average per week will consist of 2 weekdays and 1 weekend day for baseline and final week of intervention	Change from baseline to week 8 of the ~8 week experimental segment
Average (per week) daytime alertness change from baseline	5 point likert scale on daily sleep log (1= most alert; 5 = not alert at all)	Analyzed as change from baseline for each week of the ~8 week experimental segment

Collaborators and Investigators

• Sponsor: University of Utah

Study record dates

Study Major Dates

• Study Start (Actual): June 13, 2023
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): March 1, 2026

Study Registration Dates

• First Submitted: June 12, 2023
• First Submitted That Met QC Criteria: July 5, 2023
• First Posted (Actual): July 13, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 18, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Glucose Metabolism Disorders; Hyperinsulinism; Overweight; Metabolic Syndrome; Insulin Resistance
• Other Study ID Numbers: 22-60

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No