Sleep Regularity and Heart Health Study

This study is looking at how keeping a regular sleep schedule affects your heart and overall health. Researchers want to see if maintaining a consistent sleep onset time (going to bed around the same time each night, within 30 minutes) for 12 weeks can improve markers related to your heart and blood vessels. They will measure changes in your dim-light melatonin onset (a marker of your body's internal clock), something called SRI, and how well your blood vessels are working. The study is for healthy men and women aged 18 to 50, and also includes a group of people with chronic pain (fibromyalgia). The goal is to understand if better sleep regularity leads to better health.

Study design
This is an interventional study with 30 participants. It is a 12-week prospective cohort study.
What's involved
You would be asked to maintain a consistent sleep onset time (within 30 minutes of your chosen time) for 12 weeks. Data collection will involve both field and in-laboratory measurements.
Compensation
Not stated in the trial record.
Follow-up
Measurements will be taken at the beginning of the study (Week 0) and at the end (Week 12).

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NCT06535178

The Influence of Sleep on Cardiovascular Outcomes

Recruiting
NAAges 18–50Interventional
Oregon Health and Science University
~30 participants
Updated 2025-11-10 on ClinicalTrials.gov
What's tested:Sleep Regularity Group

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Changes in dim-light melatonin onset
Measured over Week 0 and Week 12
+9 more outcomes measured
Circadian Rhythm
Cardiometabolic Health
Vascular Health
Pain
1 sites across 1 states
Oregon1
  • Andrew W McHill, PhD · PRINCIPAL_INVESTIGATOR · Oregon Health and Science University

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Eligibility criteria

Inclusion

Ostensibly healthy men and women Subgroup study (chronic pain)
Satisfies diagnostic criteria for fibromyalgia according to the Widespread Pain Index - Symptom Severity (WPI-SS) scale with the following three conditions being met:

Exclusion

No history of drug or alcohol dependency.
Must be current non-smokers, and are required to have a history of less than 5 pack years of smoking.
No history of working irregular day and night hours, regular night work, or rotating shift work for the 1 year prior to the study. In addition to this, individuals must not have traveled across more than 1 time zone during the 3 months prior to the study.
Chronobiologic and sleep disorders.
Diseases of the cardiovascular system.
Hypertension. Individuals will be allowed to be normotensive (resting systolic blood pressure of \<140/90 mmHg, measured on more than one occasion) or uncomplicated stage 1 hypertension (systolic BP between 140 and 159 mmHg or a diastolic BP between 90 and 99 mmHg).
Disorders of the respiratory system.
Pre-diabetes/Diabetes. For participants who have self-reported pre-diabetes/diabetes.
Disorders of the kidney and urinary tract.
Infectious diseases.
Disorders of the gastrointestinal system.
Disorders of the immune system.
Disorders of the hematopoietic system.
Neoplastic diseases.
Endocrine and metabolic diseases.
Neurologic disorders.
Must not be participating in another research study that would influence their safe participation in the study.
  • Changes in dim-light melatonin onsetWeek 0 and Week 12

    Saliva samples will be collected pre- and post-12-week intervention and will be assayed for melatonin using standardized assays. Dim-light melatonin onset will be calculated using the linear interpolated point in time in which each participant's melatonin crosses and remains elevated above a 4pg/mL threshold. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in SRIWeek 0 and Week 12

    SRI will be calculated from 2-weeks actigraphy data prior to the first in-laboratory visit. Changes in SRI will be measured for 2-weeks during Weeks 1-2, Weeks 6-7, and Weeks 11-12 for the intervention group and during Weeks 11-12 for the control group. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in vascular endothelial functionWeek 0 and Week 12

    Vascular endothelial function will be assessed via flow mediated dilation pre- and post-12-week intervention. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in heart rateWeek 0 and Week 12

    Heart rate will be measured every \~30 minutes via a blood pressure cuff. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in blood pressureWeek 0 and Week 12

    Changes in resting blood pressure will be measured every \~30 minutes via ambulatory blood pressure machines for up to 48-hours during Weeks 1-2, Weeks 6-7, and Weeks 11-12 for the intervention group and Weeks 11-12 for the control group. Blood pressure patterns during the day and night will be assessed, as well as a contrast of day and nighttime blood pressure levels. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in resting cardiac vagal toneWeek 0 and Week 12

    High frequency power of the heart rate variability power spectrum will be used to estimate cardiac parasympathetic activity (vagal tone). These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in heart rate response to exerciseWeek 0 and Week 12

    Beat by beat heart rate will be recorded during a Monark bicycle ergometer exercise test where workload will be increased every 3-min until \~75% age predicted heart rate max is achieved. Heart rate will be averaged at rest, during each 3-min stage, and each minute during a 2-minute recovery. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in blood pressure response to exerciseWeek 0 and Week 12

    Beat by beat blood pressure will be recorded during a Monark bicycle ergometer exercise test. Blood pressure will be averaged at rest, during each 3-min stage, and each minute during a 2-minute recovery. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in energy metabolismWeek 0 and Week 12

    Resting energy expenditure and macronutrient oxidation will be measured via indirect calorimetry. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.

  • Changes in glucoseWeek 0 and Week 12

    Changes in glucose will be measures during Weeks 1-2, Weeks 6-7, and Weeks 11-12 for the intervention group and Weeks 11-12 for the control group. These data will be used to calculate mean differences and standard deviations between the control and intervention group for future experiments. Examined using planned comparison dependent t-tests to compare the changes pre- and post-12-weeks.