HypertensionNCT05184933
Sleep and Circadian Mechanisms in Hypertension
A study testing At-home Polysomnography, Circadian Protocol and Rested Wakefulness Trial in people with Hypertension and Cardiovascular Diseases, run by Oregon Health and Science University at 1 site in United States.
Trial summary
This study is a mechanistic clinical trial designed to investigate the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN). Read more about this study
- Who is it for?
- Ages 25 to 64 years
- Conditions the study is for
- Hypertension, Cardiovascular Diseases, Cardiovascular Risk Factors
- What is being tested?
- At-home Polysomnography, Circadian Protocol and Rested Wakefulness Trial
- Type of treatment
- Injection or infusion, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Aug 2022to 30 Mar 2029
- 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 25 to 64 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Ages 25-64
- BMI 18.5-42kg/m2
- Hypertension (average resting blood pressure between 130/80 mmHg and 160/100 mmHg)
Who cannot join
- Over 5 pack-years of smoking;
- Prior shift work within 12 months prior to the study;
- Travel greater than three time zones for at least 3 months;
- History of heart failure, cardiomyopathy, or history of bypass surgery, angioplasty, or previous myocardial infarction;
- Acute or chronic diseases (except hypertension) that may affect outcome measures;
- History of psychological conditions;
Show all 12Show fewer
- Sleep disorders, like severe sleep apnea, insomnia, etc.;
- Prescription medications (Contraceptives and anti-hypertensive medications are permissible);
- History of Illicit drug use and alcohol dependency;
- 30 days free of cannabis use prior to the study;
- Pregnancy;
- Upper cut-off of 160/100 mmHg for BP
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 and Science University
Portland, Oregon, 97239
Saurabh S Thosar, PhD, 503-494-2064, clinphys@ohsu.edu
Saurabh S Thosar, PhD
About this study
This study is a mechanistic clinical trial designed to investigate the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN).
Read the detailed description
This study is a mechanistic clinical trial designed to study the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN). Investigators will study participants with dipping and non-dipping hypertension. All participants will partake in all experiments. First, investigators will assess sleep in the participants' home environment using unattended polysomnography. Participants will then complete a 5-day overnight forced desynchrony laboratory protocol to uncover circadian rhythms (Constant Routine). The second experiment is a randomized crossover protocol. Two trials (Overnight Sleep and Rested Wakefulness) will be completed in randomized order to separate the effects of sleep on non-dipping blood pressure while assessing nighttime cardiovascular mechanisms. Finally, investigators will pilot test if 2 weeks of sleep regularization impacts 24-hour BP.
- Conditions
- Hypertension, Cardiovascular Diseases, Cardiovascular Risk Factors, Circadian Rhythms, Sleep
- Being tested
- At-home Polysomnography, Circadian Protocol, Rested Wakefulness Trial, Overnight Sleep Trial, Regularized Sleep Schedule
- Keywords
- cardiovascular, circadian rhythms, sleep, blood pressure, constant routine, microneurography, hypertension, sleep regularization
- Medical subject headings
- Hypertension, Cardiovascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
At-home PolysomnographyOther
Participants will complete one night of unattended polysomnography in their home environment (SOMNOtouch RESP, SOMNOmedics America Inc., FL, USA).
Circadian ProtocolOther
Also called Constant Routine
Participants will spend 4 days/3 nights in the laboratory to uncover circadian rhythms. After 2 nights for acclimatization and baseline measurements, participants will stay awake for 28 hours in dim light, constant temperature, and semi-recumbent posture. Participants will be provided with standardized snacks regularly. Polysomnography, core body temperature, sleep, finger oximetry, electrocardiogram (ECG), and beat-to-beat BP will (except microneurography) be measured throughout. Blood will be drawn every 2-4h to analyze catecholamines, renin activity, and aldosterone. All other measurements, including BP, heart rate (HR), and flow-mediated dilation will be performed regularly. Salivary samples will be collected every 2hrs (when awake) to analyze melatonin levels. A recovery sleep period will be provided and baseline testing procedures will be performed. Investigators may acquire direct recordings of sympathetic activity using microneurography.
Rested Wakefulness TrialOther
Also called Randomized crossover with overnight sleep trial
Participants will start wearing an ambulatory BP monitor upon admission. Participants will be instrumented with full polysomnography (except leg myogram), and an intravenous catheter will be placed in the non-dominant arm. Participants will receive a standardized snack, and dinner ~4 hours before the start of the trial. Participants will be instrumented for microneurography. Participants will be awake in bed in dim light (<8 lux). An investigator will constantly be present in the control room to monitor and ensure constant supine posture and wakefulness. Polysomnography, beat-by-beat BP, and neurogram for microneurography will be done throughout each trial into awakening; blood will be sampled before, during, and immediately after each trial (total of 8 samples in each trial). Flow-mediated dilation will be conducted before bed and after bed. The two trials will be conducted ~one month apart to accommodate the menstrual cycle phase in pre-menopausal females.
Overnight Sleep TrialOther
Also called Randomized crossover with rested wakefulness trial
Participants will wear an ambulatory BP monitor upon admission. Participants will be instrumented with full polysomnography (except leg myogram), and an intravenous catheter will be placed in the non-dominant arm, and then participants will receive a standardized snack, and dinner 4 hours before the start of the trial. Polysomnography, beat-by-beat BP, and neurogram for microneurography will be done throughout each trial into awakening; blood will be sampled before, during, and immediately after each trial (total of 8 samples in each trial). Participants will be instrumented for microneurography. Participants will begin an 8-hour sleep opportunity (<0.1 lux) at their chosen sleep time. At the end of the sleep episode, participants will be gently awoken in a standardized fashion by use of a mild auditory stimulus. Flow-mediated dilation will be conducted before bed and after sleep. The two trials will be conducted one month apart to accommodate the menstrual cycle.
Regularized Sleep ScheduleBehavioural
All participants will be asked to maintain a self-selected bedtime (sleep duration not controlled) for two weeks as an intervention after the completion of the constant routine and both the resting wakefulness and overnight sleep trials. During this time, participants will be asked to call a time-stamped voicemail box upon waking and going to bed, as well as complete a daily sleep diary and wear an Actigraph device on their wrist. Ambulatory blood pressure will be measured at home before and at the end of the two-week intervention.
| Study group | Role | What they receive |
|---|---|---|
| Dipping vs non-dipping HTN | Experimental | Participants will wear an ambulatory blood pressure monitor (SpaceLabs, Inc.) which will take their blood pressure in 20-30-minute intervals for 24-48 hours to determine blood pressure dipping status.
All participants in this arm will complete the experiments in this order:
1. At-home polysomnography;
2. Constant Routine protocol;
3. Rested Wakefulness Trial AND Overnight Sleep Trial (Randomized crossover);
4. Sleep Regularization Trial Receives: Other: At-home Polysomnography; Other: Circadian Protocol; Other: Rested Wakefulness Trial; Other: Overnight Sleep Trial; Behavioral: Regularized Sleep Schedule |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sleep duration (At-home Polysomnography)
Sleep duration will be scored from the ActiGraph and correlated with the sleep and activity diary. Sleep duration measures the amount of time asleep (in minutes).
Measured: 1-2 nights
Sleep Episodes (At-home Polysomnography)
Sleep episodes will be polysomnographically recorded and scored in 30-sec epochs for sleep stage, arousals, and respiratory events on SomnoMedics Domino Software. Values (based on software analysis) provide a description of what aspects of sleep are different between participants.
Measured: 1-2 nights
Blood pressure (Circadian and Overnight sleep vs. rested wakefulness trial)
Blood pressure (BP; systolic and diastolic) will be measured in a supine or semi-recumbent position. Investigators will measure beat-by-beat BP using a noninvasive device employing the volume-clamp method with hydrostatic correction. Investigators will measure BP using a calibrated sphygmomanometer to record sporadic BP at regular intervals throughout the protocols. Investigators will study circadian rhythms in blood pressure between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects blood pressure in these groups. Investigators will also study ancillary variables such as morning surge in blood pressure. All blood pressure measurements will be measured in mmHg.
Measured: 7 days
Heart rate (Circadian and Overnight sleep vs. rested wakefulness trial)
Heart rate will be measured in beats-per-minute (bpm). This is a standard marker of cardiovascular health.
Measured: 7 days
Heart rate variability (Circadian and Overnight sleep vs. rested wakefulness trial)
For the duration of all in-laboratory studies, three channels of EKG are recorded (RA-V6) and stored at a sampling frequency of 256 Hz. This software will be used for peak detection (R-wave detection and subsequent heart rate variability (HRV) analysis to estimate cardiac vagal tone). Investigators will study circadian rhythms in heart rate between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects heart rate variability in these groups. This is a measure of cardiac parasympathetic activity and cardiovascular health.
Measured: 7 days
Epinephrine (Circadian and Overnight sleep vs. rested wakefulness trial)
Plasma epinephrine (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Epinephrine between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Epinephrine in these groups.
Measured: 7 days
Norepinephrine (Circadian and Overnight sleep vs. rested wakefulness trial)
Plasma norepinephrine (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Norepinephrine between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Norepinephrine in these groups.
Measured: 7 days
Aldosterone (Circadian and Overnight sleep vs. rested wakefulness trial)
Plasma aldosterone (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Aldosterone between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Aldosterone in these groups.
Measured: 7 days
Renin (Circadian and Overnight sleep vs. rested wakefulness trial)
Plasma renin/activity (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will also study circadian rhythms in renin between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects renin in these groups.
Measured: 7 days
Vascular endothelial function (Circadian and Overnight sleep vs. rested wakefulness trial)
Investigators will measure endothelial function as flow-mediated dilation (FMD). Investigators will measure brachial artery FMD using standard procedures every 3 hours in the constant routine protocol and while awake during the overnight sleep vs. rested wakefulness trial. Investigators will also normalize FMD to the hyperemic shear. Investigators will study circadian rhythms in vascular function in people with dipping vs non-dipping hypertension. Investigators will also study if overnight sleep changes morning vascular function between these groups. Vascular function may be an indicator of cardiovascular health.
Measured: 7 days
Magnitude of overnight blood pressure dipping (Overnight sleep vs. rested wakefulness trial)
Blood Pressure (BP) dipping will be calculated as the percent reduction in average nighttime BP reduction compared to daytime BP. Both systolic and diastolic blood pressure will be measured in mmHg. Blood pressure dipping status may be an indicator of cardiovascular health. Investigators will study whether being asleep or not changes the magnitude of dipping between dipping and non-dipping hypertension. Investigators will also measure ancillary variables such as average daytime BP, night time BP, and morning surge in BP.
Measured: 2 days
Muscle sympathetic nerve activity (MSNA) (Overnight sleep vs. rested wakefulness trial and circadian trial)
MSNA may be directly measured by inserting a tungsten microelectrode (Frederick Haer, Bowdoinham, ME) into a peroneal nerve at the popliteal fossa. A reference electrode will be inserted subcutaneously 2-3 cm from the recording electrode. Both electrodes will be connected to a differential preamplifier and then to an amplifier to obtain mean voltage neurograms. Once investigators have confirmed a satisfactory post-ganglionic MSNA recording, the participants will be provided a 10 min non-recorded rest to ensure baseline levels. Data will be recorded using WinDaq/Pro data acquisition software (DATAQ Instruments, Akron, OH) and imported for analysis in the commercially available WinCPRS software program (Absolute Aliens; Turku, Finland). Investigators will also study how overnight sleep affects MSNA in these groups. Investigators may also study circadian rhythms in MSNA between people with dipping vs non-dipping hypertension.
Measured: 7 days
Secondary outcomes (2)
Ambulatory blood pressure (Sleep regularization trial)
Participants will be instructed to select a preferred bedtime time and ensure adherence to that time for 2-weeks. Investigators will not control sleep duration. After this trial, investigators will again measure 24-48 hour ambulatory BP. Both systolic and diastolic blood pressure will be measured in mmHg. Blood pressure dipping status will be assessed. BP dipping will be calculated as the percent reduction in average nighttime BP reduction compared to daytime BP. Blood pressure may be an indicator of cardiovascular health.
Measured: 2 weeks
Blood pressure dipping status (Sleep regularization trial)
Participants will be instructed to select a preferred bedtime time and ensure adherence to that time for 2-weeks. Investigators will not control sleep duration. Both systolic and diastolic blood pressure will be measured in mmHg. Blood pressure dipping status will be assessed. BP dipping will be calculated as the percent reduction in average nighttime BP reduction compared to daytime BP. Blood pressure dipping status may be an indicator of cardiovascular health.
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jan 2022
- Study start4 Aug 2022
- Primary completion31 Mar 2028 (estimated)
- Study completion30 Mar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies 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
- Not applicable
- Intervention model
- Single group
- Model description
- All participants will complete all parts of the study. The order of completion of the second experiment (Overnight Sleep and Rested Wakefulness trials) will be randomized.
- Masking
- None (open label)
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Oregon Health and Science University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Saurabh Thosar, Oregon Health and Science University
- Investigators
- Saurabh S Thosar, PhD, Principal investigator, Oregon Health and Science University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05184933
- Sponsor's protocol ID
- IRB00023776
- Status last verified
- Mar 2025
- First submitted
- 22 Dec 2021
- Last updated
- 11 Feb 2026
- 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 11 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sleep and Circadian Mechanisms in Hypertension
- ClinicalTrials.gov ID
- NCT05184933
- Acronym / sponsor ID
- IRB00023776
- Conditions
- Hypertension, Cardiovascular Diseases, Cardiovascular Risk Factors, Circadian Rhythms, Sleep
- Keywords
- cardiovascular, circadian rhythms, sleep, blood pressure, constant routine, microneurography, hypertension, sleep regularization
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Oregon Health and Science UniversityUniversity, hospital or other
- Study start
- 4 Aug 2022 (actual)
- Primary completion
- 31 Mar 2028 (estimated)
- Study completion
- 30 Mar 2029 (estimated)
- First posted
- 11 Jan 2022 (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.
This study is a mechanistic clinical trial designed to investigate the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN).
Detailed description
This study is a mechanistic clinical trial designed to study the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN). Investigators will study participants with dipping and non-dipping hypertension. All participants will partake in all experiments. First, investigators will assess sleep in the participants' home environment using unattended polysomnography. Participants will then complete a 5-day overnight forced desynchrony laboratory protocol to uncover circadian rhythms (Constant Routine). The second experiment is a randomized crossover protocol. Two trials (Overnight Sleep and Rested Wakefulness) will be completed in randomized order to separate the effects of sleep on non-dipping blood pressure while assessing nighttime cardiovascular mechanisms. Finally, investigators will pilot test if 2 weeks of sleep regularization impacts 24-hour BP.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- All participants will complete all parts of the study. The order of completion of the second experiment (Overnight Sleep and Rested Wakefulness trials) will be randomized.
| Arm | Type | Receives |
|---|---|---|
| Dipping vs non-dipping HTN | Experimental | Other: At-home Polysomnography, Other: Circadian Protocol, Other: Rested Wakefulness Trial, Other: Overnight Sleep Trial, Behavioral: Regularized Sleep ScheduleParticipants will wear an ambulatory blood pressure monitor (SpaceLabs, Inc.) which will take their blood pressure in 20-30-minute intervals for 24-48 hours to determine blood pressure dipping status. All participants in this arm will complete the experiments in this order: 1. At-home polysomnography; 2. Constant Routine protocol; 3. Rested Wakefulness Trial AND Overnight Sleep Trial (Randomized crossover); 4. Sleep Regularization Trial |
Who may qualify
- Ages
- 25 to 64 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Ages 25-64
- BMI 18.5-42kg/m2
- Hypertension (average resting blood pressure between 130/80 mmHg and 160/100 mmHg)
Key exclusion criteria (12 listed)
- Over 5 pack-years of smoking;
- Prior shift work within 12 months prior to the study;
- Travel greater than three time zones for at least 3 months;
- History of heart failure, cardiomyopathy, or history of bypass surgery, angioplasty, or previous myocardial infarction;
- Acute or chronic diseases (except hypertension) that may affect outcome measures;
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 |
|---|---|---|
| At-home PolysomnographyParticipants will complete one night of unattended polysomnography in their home environment (SOMNOtouch RESP, SOMNOmedics America Inc., FL, USA). | Other | Dipping vs non-dipping HTN |
| Circadian ProtocolAlso: Constant RoutineParticipants will spend 4 days/3 nights in the laboratory to uncover circadian rhythms. After 2 nights for acclimatization and baseline measurements, participants will stay awake for 28 hours in dim light, constant temperature, and semi-recumbent posture. Participants will be provided with standardized snacks regularly. Polysomnography, core body temperature, sleep, finger oximetry, electrocardiogram (ECG), and beat-to-beat BP will (except microneurography) be measured throughout. Blood will be drawn every 2-4h to analyze catecholamines, renin activity, and aldosterone. All other measurements, including BP, heart rate (HR), and flow-mediated dilation will be performed regularly. Salivary samples will be collected every 2hrs (when awake) to analyze melatonin levels. A recovery sleep period will be provided and baseline testing procedures will be performed. Investigators may acquire direct recordings of sympathetic activity using microneurography. | Other | Dipping vs non-dipping HTN |
| Rested Wakefulness TrialAlso: Randomized crossover with overnight sleep trialParticipants will start wearing an ambulatory BP monitor upon admission. Participants will be instrumented with full polysomnography (except leg myogram), and an intravenous catheter will be placed in the non-dominant arm. Participants will receive a standardized snack, and dinner ~4 hours before the start of the trial. Participants will be instrumented for microneurography. Participants will be awake in bed in dim light (<8 lux). An investigator will constantly be present in the control room to monitor and ensure constant supine posture and wakefulness. Polysomnography, beat-by-beat BP, and neurogram for microneurography will be done throughout each trial into awakening; blood will be sampled before, during, and immediately after each trial (total of 8 samples in each trial). Flow-mediated dilation will be conducted before bed and after bed. The two trials will be conducted ~one month apart to accommodate the menstrual cycle phase in pre-menopausal females. | Other | Dipping vs non-dipping HTN |
| Overnight Sleep TrialAlso: Randomized crossover with rested wakefulness trialParticipants will wear an ambulatory BP monitor upon admission. Participants will be instrumented with full polysomnography (except leg myogram), and an intravenous catheter will be placed in the non-dominant arm, and then participants will receive a standardized snack, and dinner 4 hours before the start of the trial. Polysomnography, beat-by-beat BP, and neurogram for microneurography will be done throughout each trial into awakening; blood will be sampled before, during, and immediately after each trial (total of 8 samples in each trial). Participants will be instrumented for microneurography. Participants will begin an 8-hour sleep opportunity (<0.1 lux) at their chosen sleep time. At the end of the sleep episode, participants will be gently awoken in a standardized fashion by use of a mild auditory stimulus. Flow-mediated dilation will be conducted before bed and after sleep. The two trials will be conducted one month apart to accommodate the menstrual cycle. | Other | Dipping vs non-dipping HTN |
| Regularized Sleep ScheduleAll participants will be asked to maintain a self-selected bedtime (sleep duration not controlled) for two weeks as an intervention after the completion of the constant routine and both the resting wakefulness and overnight sleep trials. During this time, participants will be asked to call a time-stamped voicemail box upon waking and going to bed, as well as complete a daily sleep diary and wear an Actigraph device on their wrist. Ambulatory blood pressure will be measured at home before and at the end of the two-week intervention. | Behavioural | Dipping vs non-dipping HTN |
Primary outcome
Sleep duration (At-home Polysomnography)
Time frame: 1-2 nights
Sleep duration will be scored from the ActiGraph and correlated with the sleep and activity diary. Sleep duration measures the amount of time asleep (in minutes).
Sleep Episodes (At-home Polysomnography)
Time frame: 1-2 nights
Sleep episodes will be polysomnographically recorded and scored in 30-sec epochs for sleep stage, arousals, and respiratory events on SomnoMedics Domino Software. Values (based on software analysis) provide a description of what aspects of sleep are different between participants.
Blood pressure (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Blood pressure (BP; systolic and diastolic) will be measured in a supine or semi-recumbent position. Investigators will measure beat-by-beat BP using a noninvasive device employing the volume-clamp method with hydrostatic correction. Investigators will measure BP using a calibrated sphygmomanometer to record sporadic BP at regular intervals throughout the protocols. Investigators will study circadian rhythms in blood pressure between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects blood pressure in these groups. Investigators will also study ancillary variables such as morning surge in blood pressure. All blood pressure measurements will be measured in mmHg.
Heart rate (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Heart rate will be measured in beats-per-minute (bpm). This is a standard marker of cardiovascular health.
Heart rate variability (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
For the duration of all in-laboratory studies, three channels of EKG are recorded (RA-V6) and stored at a sampling frequency of 256 Hz. This software will be used for peak detection (R-wave detection and subsequent heart rate variability (HRV) analysis to estimate cardiac vagal tone). Investigators will study circadian rhythms in heart rate between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects heart rate variability in these groups. This is a measure of cardiac parasympathetic activity and cardiovascular health.
Epinephrine (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Plasma epinephrine (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Epinephrine between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Epinephrine in these groups.
Norepinephrine (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Plasma norepinephrine (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Norepinephrine between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Norepinephrine in these groups.
Aldosterone (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Plasma aldosterone (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will study circadian rhythms in Aldosterone between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects Aldosterone in these groups.
Renin (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Plasma renin/activity (measured in plasma according to laboratory values) will be measured to estimate sympathetic output (stress). Higher values may indicate increased cardiovascular risk. Investigators will also study circadian rhythms in renin between people with dipping vs non-dipping hypertension. Investigators will also study how overnight sleep affects renin in these groups.
Vascular endothelial function (Circadian and Overnight sleep vs. rested wakefulness trial)
Time frame: 7 days
Investigators will measure endothelial function as flow-mediated dilation (FMD). Investigators will measure brachial artery FMD using standard procedures every 3 hours in the constant routine protocol and while awake during the overnight sleep vs. rested wakefulness trial. Investigators will also normalize FMD to the hyperemic shear. Investigators will study circadian rhythms in vascular function in people with dipping vs non-dipping hypertension. Investigators will also study if overnight sleep changes morning vascular function between these groups. Vascular function may be an indicator of cardiovascular health.
Magnitude of overnight blood pressure dipping (Overnight sleep vs. rested wakefulness trial)
Time frame: 2 days
Blood Pressure (BP) dipping will be calculated as the percent reduction in average nighttime BP reduction compared to daytime BP. Both systolic and diastolic blood pressure will be measured in mmHg. Blood pressure dipping status may be an indicator of cardiovascular health. Investigators will study whether being asleep or not changes the magnitude of dipping between dipping and non-dipping hypertension. Investigators will also measure ancillary variables such as average daytime BP, night time BP, and morning surge in BP.
Muscle sympathetic nerve activity (MSNA) (Overnight sleep vs. rested wakefulness trial and circadian trial)
Time frame: 7 days
MSNA may be directly measured by inserting a tungsten microelectrode (Frederick Haer, Bowdoinham, ME) into a peroneal nerve at the popliteal fossa. A reference electrode will be inserted subcutaneously 2-3 cm from the recording electrode. Both electrodes will be connected to a differential preamplifier and then to an amplifier to obtain mean voltage neurograms. Once investigators have confirmed a satisfactory post-ganglionic MSNA recording, the participants will be provided a 10 min non-recorded rest to ensure baseline levels. Data will be recorded using WinDaq/Pro data acquisition software (DATAQ Instruments, Akron, OH) and imported for analysis in the commercially available WinCPRS software program (Absolute Aliens; Turku, Finland). Investigators will also study how overnight sleep affects MSNA in these groups. Investigators may also study circadian rhythms in MSNA between people with dipping vs non-dipping hypertension.
2 secondary outcomes
Ambulatory blood pressure (Sleep regularization trial)
Time frame: 2 weeks
Blood pressure dipping status (Sleep regularization trial)
Time frame: 2 weeks
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 11 Feb 2026.
- 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.
Saurabh S Thosar, 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 At-home Polysomnography, Circadian Protocol and Rested Wakefulness Trial in people with Hypertension and Cardiovascular Diseases, 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 12 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 11 Feb 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?
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 Nicole Chaudhary, MPH (5034945536, clinphys@ohsu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sleep duration (At-home Polysomnography) (time frame: 1-2 nights). The study lists 12 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 11 Feb 2026.