Circadian Rhythms and Cardiovascular Risk

June 27, 2025 updated by: Saurabh Thosar, Oregon Health and Science University

The purpose of this study is to understand how behaviors and the effects of the body's internal clock (called the circadian pacemaker) affect the control of the heart and blood pressure.

People with Obstructive Sleep Apnea (OSA) are hypothesized to have altered circadian amplitudes in certain key indices of cardiovascular (CV) and an abnormally advanced circadian phase in some of the same key indices of CV risk. The investigators hypothesize that such changes, taken together, may explain the different timing of heart attack and sudden cardiac death in OSA.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
39

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Oregon
      • Portland, Oregon, United States, 97239
        • Oregon Health & Science University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

40 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

  • BMI less than 40
  • Moderate to severe OSA (AHI)>15
  • No current or previous pharmacological treatment for hypertension

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Obstructive Sleep Apnea
Forced Desynchrony, OSA
Behavioral: Forced Desynchrony
all sleep opportunities and other activities will be scheduled by the experimenter so that by the end of the study these activities are spread evenly across all phases of the internal body clock.
Placebo Comparator: Control
Forced Desynchrony, Control
Behavioral: Forced Desynchrony
all sleep opportunities and other activities will be scheduled by the experimenter so that by the end of the study these activities are spread evenly across all phases of the internal body clock.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Primary dependent variable: Circadian rhythm amplitude of plasma epinephrine concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma epinephrine concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma epinephrine concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma epinephrine concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of plasma epinephrine reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma epinephrine concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma epinephrine reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma epinephrine concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of plasma epinephrine reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma epinephrine concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma epinephrine reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma epinephrine concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of blood pressure (BP)
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of systolic and diastolic BP during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of blood pressure (BP)
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of systolic and diastolic BP during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of blood pressure (BP) reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in systolic and diastolic BP from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of blood pressure (BP) reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in systolic and diastolic BP from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of blood pressure (BP) reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in systolic and diastolic BP from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of blood pressure (BP) reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in systolic and diastolic BP from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of plasma cortisol concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma cortisol concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma cortisol concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma cortisol concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of plasma cortisol reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma cortisol concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma cortisol reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma cortisol concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of plasma cortisol reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma cortisol concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of plasma cortisol reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma cortisol concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of heart rate
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of heart rate during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of heart rate
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of heart rate during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of heart rate reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in heart rate from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of heart rate reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in heart rate from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of heart rate reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in heart rate from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of heart rate reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in heart rate from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of cardiac vagal tone
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of cardiac vagal tone during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of cardiac vagal tone
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of cardiac vagal tone during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of cardiac vagal tone reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in cardiac vagal tone from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of cardiac vagal tone reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in cardiac vagal tone from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm amplitude of cardiac vagal tone reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in cardiac vagal tone from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Primary dependent variable: Circadian rhythm phase of cardiac vagal tone reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in cardiac vagal tone from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Secondary dependent variable: Circadian rhythm amplitude of plasma tissue plasminogen activator inhibitor (tPA) concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma tPA concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma tPA concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma tPA concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma tPA reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma tPA concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma tPA reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma tPA concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma tPA reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma tPA concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma tPA reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma tPA concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of vascular endothelial function
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of vascular endothelial function during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of vascular endothelial function
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of vascular endothelial function during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of vascular endothelial function reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in vascular endothelial function from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of vascular endothelial function reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in vascular endothelial function from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of vascular endothelial function reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in vascular endothelial function from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of vascular endothelial function reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in vascular endothelial function from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma plasminogen activator inhibitor 1 (PAI-1) concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma PAI-1 concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma PAI-1 concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma PAI-1 concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma PAI-1 reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma PAI-1 concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma PAI-1 concentration reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma PAI-1 concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma PAI-1 reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma PAI-1 concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma PAI-1 reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma PAI-1 concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma MDA concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma MDA concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma MDA concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma MDA concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma MDA reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma MDA concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma malondialdehyde (MDA) reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma MDA concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma MDA concentration reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma MDA concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma malondialdehyde (MDA) reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma MDA concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma 8-isoprostane concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of plasma 8-isoprostane concentration during resting baseline conditions. Circadian rhythm amplitude will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma 8-isoprostane concentration
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian phase of plasma 8-isoprostane concentration during resting baseline conditions. Circadian rhythm phase will be assessed by cosinor analysis of all resting measurements obtained throughout the protocol assessed under constant conditions but at varied circadian phases and stated in relation to the reported habitual sleep time.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma 8-isoprostane reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma 8-isoprostane concentration from resting baseline to end of 15 minutes of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma 8-isoprostane reactivity to exercise
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma 8-isoprostane concentration from resting baseline to end of 15 minute of steady-state bicycle exercise. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by exercise obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm amplitude of plasma 8-isoprostane reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma 8-isoprostane concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days
Secondary dependent variable: Circadian rhythm phase of plasma 8-isoprostane reactivity to change in posture
Time Frame: Over 5 days
Comparisons will be made between participants with obstructive sleep apnea (OSA) and healthy controls of the circadian amplitude of change in plasma 8-isoprostane concentration from resting supine to end of 5 minutes of standing. Circadian rhythm amplitude of reactivity will be assessed by cosinor analysis of all changes induced by change in posture obtained throughout the protocol assessed under constant conditions but at varied circadian phases.
Over 5 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Oregon Health and Science University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Steven A Shea, PhD, Oregon Health and Science University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 9, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 9, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 17, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 25, 2014

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 29, 2014

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 2, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 27, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • OSA 00010101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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