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OpenTrials
Active, Not Recruiting

NCT Number: NCT03388788

Body Weight, Sleep, and Heart Health

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Cardiovascular Risk Factor Body Weight Chronobiology Disorders Circadian Dysregulation Nervous System Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

25 year–65 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Oregon Health & Science University

Portland, Oregon, 97239, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

  • 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)

Treatment and study plan

Positron Emission Tomography (PET) scanning of cardiac function at 3 time points across the 24 hour circadian cycle

Combination Product

Drugs are used for as part of physiological monitoring and not as interventions, including imaging using radiopharmaceuticals (11C-meta-hydroxyephedrine, and 11C-CGP12177).

Other names: PET scanning

Primary outcomes

  1. 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.

Secondary outcomes

  1. Coronary Microvascular Blood Flux

    Time frame: 3 days

    Coronary microvascular function, measured as coronary microvascular blood flux using myocardial contrast echocardiography.

  2. Flow Mediated Dilation (FMD)

    Time frame: 5 days

    FMD to measure endothelial function.

  3. Heart Rate

    Time frame: 5 Days

    Heart rate via 2-channel echocardiogram (ECG)

  4. Epinephrine

    Time frame: 5 days

    Venous Epinephrine to estimate sympathetic output

  5. Norepinephrine

    Time frame: 5 days

    Venous Norepinephrine to estimate sympathetic output

  6. Cortisol

    Time frame: 5 days

    Saliva cortisol to estimate sympathetic output

Other outcomes

  1. Beta-adrenergic Receptor Density (Exploratory Outcome)

    Time frame: 5 days.

    Radiolabeled agonist (11C-CGP12177) to measure beta-adrenergic receptors during PET Imaging.

  2. Norepinephrine Reuptake Transport (Exploratory Outcome)

    Time frame: 5 days.

    Radiolabeled meta-hydroxyephedrine (11C-mHED) to measure norepinephrine reuptake during PET Imaging.

Sponsors and collaborators

Lead sponsor

Oregon Health and Science University

Other

Collaborators

  • National Center for Advancing Translational Sciences (NCATS)
  • National Heart, Lung, and Blood Institute (NHLBI)

Registry information

Official study title

Circadian Mechanisms of Cardiovascular Risk in Obesity

Important dates

Study start
2018
Primary completion
2024
Study completion
2026
First posted
Jan 3, 2018
Registry last updated
May 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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