Circadian RhythmDISCONCT06535178
The Influence of Sleep on Cardiovascular Outcomes
A study testing Sleep Regularity Group in people with Circadian Rhythm and Cardiometabolic Health, run by Oregon Health and Science University at 1 site in United States.
Trial summary
The goal of this study is to identify the effects of sleep regularity on cardiovascular regulatory mechanisms. The investigators are hoping to discover if improving the regularity of sleep timing will improve metabolic and vascular health markers. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Circadian Rhythm, Cardiometabolic Health, Vascular Health
- What is being tested?
- Sleep Regularity Group
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2024to 30 Sep 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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:
- Widespread pain index (WPI) ≥7 and symptom severity (SS) scale score ≥5 or WPI 3-6 and SS scale score ≥9.
- Symptoms have been present at a similar level for at least 3 months.
- The patient does not have a disorder that would otherwise explain the pain.
Who cannot join
- 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).
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Oregon Health & Science University
Portland, Oregon, 97239
Andrew McHill, PhD, (503) 949-2594, mchill@ohsu.edu
About this study
Official title: Determining the Influence of Sleep on Cardiovascular Outcomes
The goal of this study is to identify the effects of sleep regularity on cardiovascular regulatory mechanisms. The investigators are hoping to discover if improving the regularity of sleep timing will improve metabolic and vascular health markers. The protocol is a 12-week prospective cohort study that includes both field and in-laboratory data collection in ostensibly healthy male and female adults, aged 18-40years. We will also have a sub-group of individuals with chronic pain to examine the effects of sleep regularity on pain outcomes.
Read the detailed description
Sleep is a fundamental determinant of heath; however, the impact of day-to-day variations in sleep patterns (i.e., sleep regularity) on cardiometabolic and vascular health has been underappreciated. Emerging evidence suggests that less regularity in sleep timing is correlated with cardiometabolic health and is a stronger predictor of mortality risk than sleep duration. In this cohort, the investigators will determine the influence of sleep regularity on mechanisms that impact cardiometabolic, vascular, and autonomic function.
The misalignment of behaviors (e.g., sleep) with the internal timing system (i.e., circadian misalignment) is likely a mechanistic contributor to unfavorable health outcomes. Laboratory experiments have shown that acute circadian misalignment increases markers of inflammation, alters metabolism, and elevates mean arterial pressure. We have shown that poorer overnight blood pressure dipping patterns are associated with circadian disruptions elicited by decreased sleep regularity, which occurs within 90-days of transitioning to a shift work schedule. There is a need to characterize the influence of sleep regularity on the underlying pathways that affect health.
The goal of this study is to determine the effect of an intervention targeting improved sleep regularity on circadian, metabolic, and vascular health markers. Participants within the lowest tertile for sleep regularity will adhere to a consistent sleep onset time (±30 min) for approximately 12-weeks. The outcomes that the investigators will focus on will be indices of hemodynamics (blood pressure, heart rate, autonomic function), blood biomarkers (markers of inflammation, oxidative stress, and triglycerides), energy metabolism, weight, and percent body fat. We will also have a sub-group of individuals with chronic pain to examine the effects of sleep regularity on pain outcomes.
- Outpatient Biobehavioral Weeks: Actigraphy data will be collected across 2-weeks to assess habitual sleep patterns and calculate a sleep regularity index (SRI).
- Biobehavioral Laboratory Visit: Participants will be asked to visit the OHSU School of Nursing (SON) Biobehavioral Laboratory space for two in-laboratory visits in dim-light settings, which will involve an evening stay (~7.5h) to measure circadian markers, body composition, vascular function, and questionnaire data. Saliva samples will also be collected via salivettes in order to measure the hormone melatonin and determine each participants' dim-light melatonin onset (DLMO). Participants lowest SRI tertile (intervention group) will be instructed to maintain a consistent sleep onset time (±30 min self-selected sleep time) for up to 12-weeks. Compliance will be assessed across 6-weeks of outpatient bio-behavioral data collection via sleep logs, actigraphy, and daily surveys (described below). All other participants (control group) will be instructed to maintain their habitual sleep patterns for up to 12-weeks.
- Ambulatory Monitoring: For participants in the intervention group, biobehavioral data collection will occur at Weeks 1-2, Weeks 6-7, and Weeks 11-12. For the control group, biobehavioral data collection will occur at Weeks 11-12. During these weeks, participants will wear an actigraphy device and keep sleep logs for 2-weeks during the biobehavioral data collection. Participants will also wear an ambulatory blood pressure cuff. Additionally, to measure glucose levels throughout the protocol, participants will be fitted with a continuous glucose monitor. Participants will complete daily surveys each bio-behavioral period to measure self-reported bed and wake times and naps.
- Blood Biomarkers: At baseline and at Week 12, participants will visit the SON Biobehavioral Laboratory for a blood draw to obtain markers of inflammation, oxidative stress, and lipemic markers that will be measured with an ~10mL blood draw.
- Conditions
- Circadian Rhythm, Cardiometabolic Health, Vascular Health, Pain
- Being tested
- Sleep Regularity Group
- Keywords
- Circadian Rhythm, Cardiometabolic Health, Vascular Health, Pain
- Medical subject headings
- Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sleep Regularity GroupBehavioural
Maintained consistent sleep onset time (±30 min self-selected sleep time) for 12-weeks.
| Study group | Role | What they receive |
|---|---|---|
| Sleep Regularity Group | Experimental | Individuals in the lowest SRI tertile will begin the 12-week intervention to improve sleep regularity. Participants will be instructed to maintain a consistent sleep onset time (±30 min self-selected sleep time). Receives: Behavioral: Sleep Regularity Group |
| Control Group | No intervention | All other participants will be instructed to maintain their habitual sleep patterns. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in dim-light melatonin onset
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.
Measured: Week 0 and Week 12
Changes in SRI
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.
Measured: Week 0 and Week 12
Changes in vascular endothelial function
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.
Measured: Week 0 and Week 12
Changes in heart rate
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.
Measured: Week 0 and Week 12
Changes in blood pressure
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.
Measured: Week 0 and Week 12
Changes in resting cardiac vagal tone
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.
Measured: Week 0 and Week 12
Changes in heart rate response to exercise
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.
Measured: Week 0 and Week 12
Changes in blood pressure response to exercise
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.
Measured: Week 0 and Week 12
Changes in energy metabolism
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.
Measured: Week 0 and Week 12
Changes in glucose
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.
Measured: Week 0 and Week 12
Secondary outcomes (9)
Changes in MDA
Changes in malondialdehyde [MDA] will be measured 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.
Measured: Week 0 and Week 12
Changes in TAC
Changes in total antioxidant capacity [TAC] will be measured 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.
Measured: Week 0 and Week 12
Changes in CRP
Changes in C-reactive protein [CRP] will be measured 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.
Measured: Week 0 and Week 12
Changes in triglycerides
Changes in triglycerides will be measured 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.
Measured: Week 0 and Week 12
Changes in percent body fat
Percent body fat will be assessed via dual x-ray absorptiometry [DEXA] and a Tanita body composition scale in all participants at baseline. Changes in percent body fat will be assessed via DEXA (Intervention Group) and Tanita body composition scale (Control Group) post-12-weeks. 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.
Measured: Week 0 and Week 12
Changes in weight
Weight will be assessed via dual x-ray absorptiometry [DEXA] and a Tanita body composition scale in all participants at baseline. Changes in weight will be assessed via DEXA (Intervention Group) and Tanita body composition scale (Control Group) post-12-weeks. 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.
Measured: Week 0 and Week 12
Changes in BMI
Body mass index [BMI] will be assessed via dual x-ray absorptiometry [DEXA] and a Tanita body composition scale in all participants at baseline. Changes in BMI will be assessed via DEXA (Intervention Group) and Tanita body composition scale (Control Group) post-12-weeks. 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.
Measured: Week 0 and Week 12
Changes in PIPR
Changes in post illumination pupil response [PIPR] will be measured using a near-infrared illumination and solid-state video 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.
Measured: Week 0 and Week 12
Subjective Pain
Participants will rate feelings of subjective pain on visual analog scales.
Measured: Week 0 and Week 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2024
- Study start1 Jul 2024
- Primary completion30 Sep 2026 (estimated)
- Study completion30 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Circadian RhythmStudies of the same condition, open and under way.
- More trials run by Oregon Health and Science UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Oregon Health and Science University
- Sponsor type
- University, hospital or other
- Collaborators
- Medical Research Foundation, Oregon
- Responsible party
- Principal investigator, Andrew McHill, Oregon Health and Science University
- Investigators
- Andrew W McHill, PhD, Principal investigator, Oregon Health and Science University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06535178
- Sponsor's protocol ID
- STUDY00026854
- Acronym
- DISCO
- Status last verified
- Nov 2025
- First submitted
- 31 Jul 2024
- Last updated
- 10 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Determining the Influence of Sleep on Cardiovascular Outcomes
- ClinicalTrials.gov ID
- NCT06535178
- Acronym / sponsor ID
- DISCO / STUDY00026854
- Conditions
- Circadian Rhythm, Cardiometabolic Health, Vascular Health, Pain
- Keywords
- Circadian Rhythm, Cardiometabolic Health, Vascular Health, Pain
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Oregon Health and Science UniversityUniversity, hospital or other
- Collaborators
- Medical Research Foundation, Oregon
- Study start
- 1 Jul 2024 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 30 Sep 2026 (estimated)
- First posted
- 2 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to identify the effects of sleep regularity on cardiovascular regulatory mechanisms. The investigators are hoping to discover if improving the regularity of sleep timing will improve metabolic and vascular health markers. The protocol is a 12-week prospective cohort study that includes both field and in-laboratory data collection in ostensibly healthy male and female adults, aged 18-40years. We will also have a sub-group of individuals with chronic pain to examine the effects of sleep regularity on pain outcomes.
Detailed description
Sleep is a fundamental determinant of heath; however, the impact of day-to-day variations in sleep patterns (i.e., sleep regularity) on cardiometabolic and vascular health has been underappreciated. Emerging evidence suggests that less regularity in sleep timing is correlated with cardiometabolic health and is a stronger predictor of mortality risk than sleep duration. In this cohort, the investigators will determine the influence of sleep regularity on mechanisms that impact cardiometabolic, vascular, and autonomic function.
The misalignment of behaviors (e.g., sleep) with the internal timing system (i.e., circadian misalignment) is likely a mechanistic contributor to unfavorable health outcomes. Laboratory experiments have shown that acute circadian misalignment increases markers of inflammation, alters metabolism, and elevates mean arterial pressure. We have shown that poorer overnight blood pressure dipping patterns are associated with circadian disruptions elicited by decreased sleep regularity, which occurs within 90-days of transitioning to a shift work schedule. There is a need to characterize the influence of sleep regularity on the underlying pathways that affect health.
The goal of this study is to determine the effect of an intervention targeting improved sleep regularity on circadian, metabolic, and vascular health markers. Participants within the lowest tertile for sleep regularity will adhere to a consistent sleep onset time (±30 min) for approximately 12-weeks. The outcomes that the investigators will focus on will be indices of hemodynamics (blood pressure, heart rate, autonomic function), blood biomarkers (markers of inflammation, oxidative stress, and triglycerides), energy metabolism, weight, and percent body fat. We will also have a sub-group of individuals with chronic pain to examine the effects of sleep regularity on pain outcomes.
- Outpatient Biobehavioral Weeks: Actigraphy data will be collected across 2-weeks to assess habitual sleep patterns and calculate a sleep regularity index (SRI).
- Biobehavioral Laboratory Visit: Participants will be asked to visit the OHSU School of Nursing (SON) Biobehavioral Laboratory space for two in-laboratory visits in dim-light settings, which will involve an evening stay (~7.5h) to measure circadian markers, body composition, vascular function, and questionnaire data. Saliva samples will also be collected via salivettes in order to measure the hormone melatonin and determine each participants' dim-light melatonin onset (DLMO). Participants lowest SRI tertile (intervention group) will be instructed to maintain a consistent sleep onset time (±30 min self-selected sleep time) for up to 12-weeks. Compliance will be assessed across 6-weeks of outpatient bio-behavioral data collection via sleep logs, actigraphy, and daily surveys (described below). All other participants (control group) will be instructed to maintain their habitual sleep patterns for up to 12-weeks.
- Ambulatory Monitoring: For participants in the intervention group, biobehavioral data collection will occur at Weeks 1-2, Weeks 6-7, and Weeks 11-12. For the control group, biobehavioral data collection will occur at Weeks 11-12. During these weeks, participants will wear an actigraphy device and keep sleep logs for 2-weeks during the biobehavioral data collection. Participants will also wear an ambulatory blood pressure cuff. Additionally, to measure glucose levels throughout the protocol, participants will be fitted with a continuous glucose monitor. Participants will complete daily surveys each bio-behavioral period to measure self-reported bed and wake times and naps.
- Blood Biomarkers: At baseline and at Week 12, participants will visit the SON Biobehavioral Laboratory for a blood draw to obtain markers of inflammation, oxidative stress, and lipemic markers that will be measured with an ~10mL blood draw.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sleep Regularity Group | Experimental | Behavioral: Sleep Regularity GroupIndividuals in the lowest SRI tertile will begin the 12-week intervention to improve sleep regularity. Participants will be instructed to maintain a consistent sleep onset time (±30 min self-selected sleep time). |
| Control Group | No intervention | –All other participants will be instructed to maintain their habitual sleep patterns. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- 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:
Key exclusion criteria (17 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Sleep Regularity GroupMaintained consistent sleep onset time (±30 min self-selected sleep time) for 12-weeks. | Behavioural | Sleep Regularity Group |
Primary outcome
Changes in dim-light melatonin onset
Time frame: Week 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 SRI
Time frame: Week 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 function
Time frame: Week 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 rate
Time frame: Week 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 pressure
Time frame: Week 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 tone
Time frame: Week 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 exercise
Time frame: Week 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 exercise
Time frame: Week 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 metabolism
Time frame: Week 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 glucose
Time frame: Week 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.
9 secondary outcomes
Changes in MDA
Time frame: Week 0 and Week 12
Changes in TAC
Time frame: Week 0 and Week 12
Changes in CRP
Time frame: Week 0 and Week 12
Changes in triglycerides
Time frame: Week 0 and Week 12
Changes in percent body fat
Time frame: Week 0 and Week 12
Changes in weight
Time frame: Week 0 and Week 12
Changes in BMI
Time frame: Week 0 and Week 12
Changes in PIPR
Time frame: Week 0 and Week 12
Subjective Pain
Time frame: Week 0 and Week 12
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Nov 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Andrew W McHill, PhD principal investigator
Oregon Health and Science University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sleep Regularity Group in people with Circadian Rhythm and Cardiometabolic Health, run by Oregon Health and Science University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 10 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Andrew W McHill, PhD ((503) 494 - 2594, mchill@ohsu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in dim-light melatonin onset (time frame: Week 0 and Week 12). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Nov 2025.