Cardiovascular Risk FactorNCT03388788

Body Weight, Sleep, and Heart Health

An observational study of Cardiovascular Risk Factor and Circadian Dysregulation, run by Oregon Health and Science University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Who is it for?: Ages 25 to 65 yearsHealthy volunteers can take part
Conditions the study is for: Cardiovascular Risk Factor, Circadian Dysregulation, Obesity
What is being tested?: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycle
How many people: 17 participants
Where: 1 siteUnited States
Study dates: 1 May 2018to 30 Jun 2026
Phase: Observational
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 25 to 65 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Study population: Community sample

Who may be able to join

Ages 25-65
Lean and overweight (BMI 18.5-40kg/m2)
Habitually sedentary

Who cannot join

History of smoking/tobacco use
Insomnia
Moderate to severe obstructive sleep apnea.
Prior shift work within 6 months prior to the study.
Prescription medications
Drugs of abuse
Acute, chronic, or debilitating medical condition (including diabetes, hypertension, and metabolic syndrome)

Trial locations and contacts

1 site in 1 country.

United States1 site

Oregon Health & Science University
Portland, Oregon, 97239

Other trials in United States

About this study

Official title: Circadian Mechanisms of Cardiovascular Risk in Obesity

A multidisciplinary investigation examining the circadian mechanisms regulating cardiovascular (CV) risk, with an additional focus on obesity. Specifically, in a valid circadian protocol, the investigators aim to study resting cardiovascular risk markers and the reactivity of circadian rhythms in these risk markers to standardized stressors. It is intended to compare results in lean and obese individuals to determine if there are specific risks across the circadian cycle specific to obesity. Furthermore, using an exploratory approach, the investigators propose to explore impairment in pre/post synaptic function in the cardiac left ventricle.

Read the detailed description

Overall, these studies will help us answer whether the circadian system predispose individuals to increased CV disease risk - particularly around the vulnerable morning period, and whether these risks differ with obesity. The results will serve as a foundation for clinical trials of appropriately timed dosing of medications targeting aspects of the CV system that increase effectiveness while decreasing side effects, and may have particular relevance to management of CV risk in people with obesity.

Conditions: Cardiovascular Risk Factor, Circadian Dysregulation, Obesity
Being tested: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycle
Medical subject headings: Chronobiology Disorders, Obesity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycleCombination product
Also called PET scanning
Drugs are used for as part of physiological monitoring and not as interventions, including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177).

Study groups in NCT03388788
Study group	Role	What they receive
Normal Weight		Healthy lean controls [18.5<BMI<25 kg/m2 and waist circumference <94/80 cm (men/women respectively)] will participate in a 5-day circadian study protocol with numerous repeated cardiovascular measures across the circadian cycle. Drugs are used as part of physiological monitoring and not as interventions including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177). Receives: Combination Product: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycle
Overweight		Healthy obese [30≤BMI<40 and waist circumference ≥94/80 (men and women respectively)] Healthy lean controls [18.5<BMI<25 kg/m2 and waist circumference <94/80 cm (men/women respectively)] will participate in a 5-day circadian study protocol with numerous repeated cardiovascular measures across the circadian cycle. Drugs are used as part of physiological monitoring and not as interventions including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177). Receives: Combination Product: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycle

What is being measured

The primary outcome is the main question the study is designed to answer.

Blood Pressure (BP)
Measurements were collected up to 7 times per participant across the circadian cycle under constant conditions across 5 days. Resting BP and Exercise BP data were collected at the beginning of each of 7 wake periods in a supine position and where participants exercised at an intensity equivalent to brisk walking. Salivary melatonin was used to calculate the circadian phase marker using dim light melatonin onset (DLMO). All data were assigned a circadian phase relative to DLMO and binned into 4-hour (or 60-degree) intervals. In the statistical analysis, the weight group refers to normal or overweight, exercise condition refers to seated or exercising on the bike, and circadian phase refers to the center of the circadian bin. This is an observational study. Due to insufficient enrollment and an imbalanced group distribution, we do not have sufficient statistical power to fully interpret these data. The data are valuable as pilot data for future investigations and sample size estimation.
Measured: 5 Days

Secondary outcomes (6)

Coronary Microvascular Blood Flux
Coronary microvascular function, measured as coronary microvascular blood flux using myocardial contrast echocardiography.
Measured: 3 days
Flow Mediated Dilation (FMD)
FMD to measure endothelial function.
Measured: 5 days
Heart Rate
Heart rate via 2-channel echocardiogram (ECG)
Measured: 5 Days
Epinephrine
Venous Epinephrine to estimate sympathetic output
Measured: 5 days
Norepinephrine
Venous Norepinephrine to estimate sympathetic output
Measured: 5 days
Cortisol
Saliva cortisol to estimate sympathetic output
Measured: 5 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1 May 201830 Jun 2026

First posted3 Jan 2018
Study start1 May 2018
Primary completion30 Sep 2024
Study completion30 Jun 2026

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Cardiovascular Risk FactorStudies 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: Observational
Observational model: Other
Time perspective: Prospective
Enrolment: 17 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03388788
Sponsor's protocol ID: IRB00017489
Other IDs: R01HL140577, KL2TR002370
Status last verified: Oct 2026
First submitted: 20 Dec 2017
Last updated: 4 Nov 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Active, not recruitingObservational study
A Longitudinal Cohort Study to Evaluate Cardiovascular Risk Factors and Disease in Haiti
Hypertension, Diabetes
RecruitingPhase 3
A Study of Orforglipron in Participants With Overweight at Risk of Development of Obesity-Related Complications or Progression to Class 1 Obesity
Overweight, Prediabetic State
RecruitingObservational study
Characterization of Patients With Uncommon Presentations and/or Uncommon Diseases Associated With the Cardiovascular System
Metabolic Disease, Obesity
Not yet recruiting
Multimodal AI-Driven Out-of-Hospital Management for Hypertension and Cardiometabolic Risk
Hypertension, Hyperglycemia
Recruiting
Determining Efficacy of an Artificial Intelligence-based System for Heart Failure Detection Through Interpretation of Electrocardiograms (DECISION)
Heart Failure, Cardiovascular Risk Factors

All Cardiovascular Risk Factor trials

Study at a glance

From the registry record, last updated by the sponsor on 4 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Circadian Mechanisms of Cardiovascular Risk in Obesity
ClinicalTrials.gov ID: NCT03388788
Acronym / sponsor ID: IRB00017489
Conditions: Cardiovascular Risk Factor, Circadian Dysregulation, Obesity
Study type: Observational
Recruitment status: Completed
Enrolment: 17 participants (actual)
Lead sponsor: Oregon Health and Science UniversityUniversity, hospital or other
Collaborators: National Heart, Lung, and Blood Institute (NHLBI), National Center for Advancing Translational Sciences (NCATS)
Study start: 1 May 2018 (actual)
Primary completion: 30 Sep 2024 (actual)
Study completion: 30 Jun 2026 (actual)
First posted: 3 Jan 2018 (actual)
Results: Posted 18 May 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Observational model: Other
Time perspective: Prospective
Number of arms: 2

Arm	Type	Receives
Normal Weight	–	Combination Product: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycleHealthy lean controls [18.5<BMI<25 kg/m2 and waist circumference <94/80 cm (men/women respectively)] will participate in a 5-day circadian study protocol with numerous repeated cardiovascular measures across the circadian cycle. Drugs are used as part of physiological monitoring and not as interventions including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177).
Overweight	–	Combination Product: Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycleHealthy obese [30≤BMI<40 and waist circumference ≥94/80 (men and women respectively)] Healthy lean controls [18.5<BMI<25 kg/m2 and waist circumference <94/80 cm (men/women respectively)] will participate in a 5-day circadian study protocol with numerous repeated cardiovascular measures across the circadian cycle. Drugs are used as part of physiological monitoring and not as interventions including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177).

Who may qualify

Ages: 25 to 65 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult
Study population: Community sample

Key inclusion criteria (3 listed)

Ages 25-65
Lean and overweight (BMI 18.5-40kg/m2)
Habitually sedentary

Key exclusion criteria (7 listed)

History of smoking/tobacco use
Insomnia
Moderate to severe obstructive sleep apnea.
Prior shift work within 6 months prior to the study.
Prescription medications

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
Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycleAlso: PET scanningDrugs are used for as part of physiological monitoring and not as interventions, including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177).	Combination product	Normal Weight, Overweight

Primary outcome

Blood Pressure (BP)
Time frame: 5 Days
Measurements were collected up to 7 times per participant across the circadian cycle under constant conditions across 5 days. Resting BP and Exercise BP data were collected at the beginning of each of 7 wake periods in a supine position and where participants exercised at an intensity equivalent to brisk walking. Salivary melatonin was used to calculate the circadian phase marker using dim light melatonin onset (DLMO). All data were assigned a circadian phase relative to DLMO and binned into 4-hour (or 60-degree) intervals. In the statistical analysis, the weight group refers to normal or overweight, exercise condition refers to seated or exercising on the bike, and circadian phase refers to the center of the circadian bin. This is an observational study. Due to insufficient enrollment and an imbalanced group distribution, we do not have sufficient statistical power to fully interpret these data. The data are valuable as pilot data for future investigations and sample size estimation.

6 secondary outcomes

Coronary Microvascular Blood Flux
Time frame: 3 days
Flow Mediated Dilation (FMD)
Time frame: 5 days
Heart Rate
Time frame: 5 Days
Epinephrine
Time frame: 5 days
Norepinephrine
Time frame: 5 days
Cortisol
Time frame: 5 days

Results and safety

Results posted to the registry on 18 May 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Normal Weight	12	11
Overweight	5	5

Primary outcome: Blood Pressure (BP)

Time frame: 5 Days. Mean (Standard Error). Unit: mmHg

Measure	Normal Weight n = 11	Overweight n = 5
Supine Resting Systolic BP across the circadian cycle (see details below for statistical test)	111.27 (2.91)	113.99 (4.47)
Supine Resting Diastolic BP across the circadian cycle (see details below for statistical test)	60.05 (1.96)	59.96 (3.00)
Seated Resting Systolic BP across the circadian cycle (see below for statistical tests)	107.95 (3.78)	111.63 (5.90)
Seated Exercise Systolic BP across the circadian cycle (see below for statistical tests)	140.95 (3.78)	148.42 (5.81)
Seated Resting Diastolic BP across the circadian cycle (see below for statistical tests)	68.28 (1.33)	71.86 (2.11)
Seated Exercise Diastolic BP across the circadian cycle (see below for statistical tests)	61.31 (1.34)	72.61 (2.08)

Normal Weight vs Overweight: p = 0.18, Mixed Models Analysis
Normal Weight vs Overweight: p = 0.28, Mixed Models Analysis
Normal Weight vs Overweight: p = 0.33, Mixed Models Analysis

Population analysed: These data were collected from an oscillometric blood pressure device.

6 secondary outcomes are reported in the full results.

Adverse events

Time frame: From enrollment until end of follow-up (1 week after the in-laboratory monitoring). Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Normal Weight	0 of 12 (0%)	5 of 12 (41.7%)	0 of 12
Overweight	0 of 5 (0%)	3 of 5 (60%)	0 of 5

Limitations and caveats (from the sponsor): For the exploratory aim, the complex circadian PET protocol was operationally challenging and only partially completed. Short tracer half-lives, lack of automation, tight timing, and overnight chemistry variability caused synthesis issues; plus COVID and staff loss constrained execution. Of 895 screened, 16 enrolled, with no complete datasets. Thus, statistical power and interpretation are limited. These data serve as pilot data; future feasibility will require more personnel, and automation.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 4 Nov 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Cardiovascular Risk Factor

Active, not recruitingObservational study
A Longitudinal Cohort Study to Evaluate Cardiovascular Risk Factors and Disease in Haiti
Hypertension, Diabetes
RecruitingPhase 3
A Study of Orforglipron in Participants With Overweight at Risk of Development of Obesity-Related Complications or Progression to Class 1 Obesity
Overweight, Prediabetic State
RecruitingObservational study
Characterization of Patients With Uncommon Presentations and/or Uncommon Diseases Associated With the Cardiovascular System
Metabolic Disease, Obesity
Not yet recruiting
Multimodal AI-Driven Out-of-Hospital Management for Hypertension and Cardiometabolic Risk
Hypertension, Hyperglycemia
Recruiting
Determining Efficacy of an Artificial Intelligence-based System for Heart Failure Detection Through Interpretation of Electrocardiograms (DECISION)
Heart Failure, Cardiovascular Risk Factors

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. This study is not recruiting at the moment.

Steven A Shea, PhD principal investigator

Oregon Institute of Occupational Health Sciences

Jeanne M Link, PhD principal investigator

OHSU Center for Radiochemistry Research

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of Cardiovascular Risk Factor and Circadian Dysregulation, 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 3 inclusion and 7 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: finished, as of the sponsor's last update on 4 Nov 2026. 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?

Yes. Results are posted in the registry (first posted 18 May 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Blood Pressure (BP) (time frame: 5 Days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03388788.

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 4 Nov 2026.