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Circadian Intervention to Improve Cardiometabolic Health

Timing of Circadian Synchronizers: The TOCS Study

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05943626
Acronym
TOCS
Enrollment
20
Registered
2023-07-13
Start date
2023-06-13
Completion date
2027-06-01
Last updated
2026-08-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiometabolic Syndrome, Eating Habit, Insulin Sensitivity, Lifestyle Factors, Overweight and Obesity, Sleep, Sleep Hygiene, Time Restricted Feeding, Type 2 Diabetes

Brief summary

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).

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.

Interventions

BEHAVIORALCircadian 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.

Sponsors

University of Utah
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)

Masking description

Group allocation will be blinded to research staff and participants until the conclusion of the baseline segment.

Eligibility

Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Insulin sensitivity change from baselineChange from baseline to end of the ~8 week experimental segmentOral Glucose Tolerance Test (OGTT), Matsuda Index

Secondary

MeasureTime frameDescription
Timing of central circadian clock change from baselineChange from baseline to end of the ~8 week experimental segmentQuantified as dim-light melatonin onset from salivary melatonin samples
Plasma ceramides change from baselineChange from baseline to end of the ~8 week experimental segmentFasting plasma samples will be analyzed for plasma ceramides using targeted metabolomics
Average (per week) nightly total sleep time change from baselineAnalyzed as change from baseline for each week of the ~8 week experimental segmentAnalyzed by wrist-actigraphy
Average (per week) sleep satisfaction change from baselineAnalyzed as change from baseline for each week of the ~8 week experimental segment5 point likert scale on daily sleep log (1 = very good; 5 = very poor)
Average (per week) self-reported sleep duration change from baselineAnalyzed as change from baseline for each week of the ~8 week experimental segmentDaily electronic sleep logs will be used to track sleep and waketimes during the ambulatory monitoring phases of the study
Average (per week) timing of food intake change from baselineChange from baseline to week 8 of the ~8 week experimental segmentTime 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
Average (per week) daytime alertness change from baselineAnalyzed as change from baseline for each week of the ~8 week experimental segment5 point likert scale on daily sleep log (1= most alert; 5 = not alert at all)

Countries

United States

Contacts

CONTACTChristopher M Depner, PhD
christopher.depner@utah.edu801-581-2275

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 6, 2026