HypertensionNCT03558893

Sleep and Circadian Mechanisms of Non-dipping Blood Pressure

A study testing Forced Desynchrony in people with Hypertension and Cardiovascular Risk Factor, 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

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Trial summary

Who is it for?: Ages 30 to 60 yearsHealthy volunteers can take part
Conditions the study is for: Hypertension, Cardiovascular Risk Factor
What is being tested?: Forced Desynchrony
Type of treatment: Pill or oral medicine, Lifestyle or therapy programme
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 30 participants
Where: 1 siteUnited States
Study dates: 1 Dec 2018to 31 Dec 2024
Phase: Interventional
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 30 to 60 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

Self-identified Black or White
'normotensive' (resting systolic blood pressure (SBP) <140/90 mmHg) or uncomplicated stage 1 'hypertensive' (systolic BP between 140 and 160 mmHg or a diastolic (DBP) between 90 and 100 mmHg).
free of all prescription and non-prescription drugs (including caffeine, nicotine, alcohol and herbal medications)

Who cannot join

Currently treated with pharmacologic agents for hypertension
Blood pressure >160/100 mmHg
Smoked within the last year
Regular night work or rotating shift work for the three months prior to the study
Travel across more than three time zones during the three months prior to the study.
Any acute, chronic or debilitating medical conditions, other than mild hypertension (140<SBP<160 or 90<DBP<100 mmHg) and severe renal disease (glomerular filtration rate <30)
Moderate to severe obstructive sleep apnea (OSA)
History of severe psychiatric illnesses or psychiatric disorders will be excluded, including alcoholism, drug dependency, major depression, manic depressive illness, schizophrenic disorders, panic disorder, generalized anxiety disorder, post-traumatic stress disorder, agoraphobia, claustrophobia, paranoid personality disorder, schizoid personality disorder, schizotypal personality disorder, borderline personality disorder, and antisocial personality disorder.

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: Sleep and Circadian Mechanisms Contributing to Nocturnal Non-dipping Blood Pressure

This study will be the first to distinguish the relative contributions of sleep, circadian and behavioral mechanisms to the non-dipping BP profile in Black adults and will lay the groundwork for optimizing therapies dependent on mechanisms, such as targeting sleep, targeting circadian rhythmicity, or targeting behaviors, and raising the possibility that ideal therapy for hypertension (HTN) may differ by race. This research will ultimately help to improve health and survival in black populations with HTN.

Read the detailed description

By studying standardized behaviors and regulators of BP during sleep and behavioral stresses across all circadian phases, this protocol will allow us specifically to:

To determine if poor sleep, while controlling for circadian phase, contributes to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.
To determine if reduced BP responses to standardized behavioral changes across the day and night contribute to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.
To determine if reduced circadian amplitude of BP contributes to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.

Conditions: Hypertension, Cardiovascular Risk Factor
Being tested: Forced Desynchrony
Keywords: circadian rhythm
Medical subject headings: Hypertension

What participants receive

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

Forced DesynchronyBehavioural
Participants will complete a 7-day circadian study protocol with numerous repeated blood pressure and other cardiovascular measures across the circadian cycle. 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.

Study groups in NCT03558893
Study group	Role	What they receive
White Adults	Other	White adults aged 30-60 with a BMI of 18.5<BMI<40 kg/m2 who are non-smokers (≥1 year), not on prescription medications (except oral contraceptives), and have had no recent shift work or major travel. Mild, unmanaged hypertension (below 160/100) and renal disease are allowed. Receives: Behavioral: Forced Desynchrony
Black Adults	Other	Black adults aged 30-60 with a BMI of 18.5<BMI<40 kg/m2 who are non-smokers (≥1 year), not on prescription medications (except oral contraceptives), and have had no recent shift work or major travel. Mild, unmanaged hypertension (below 160/100) and renal disease are allowed. Receives: Behavioral: Forced Desynchrony

What is being measured

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

Nighttime Systolic Blood Pressure
Systolic blood pressure measured via automatic sphygmomanometer every 30 minutes during sleep period at baseline. Readings recorded in units of mmHg.
Measured: Baseline Night Average
Nighttime Diastolic Blood Pressure
Diastolic blood pressure measured via automatic sphygmomanometer every 30 minutes during sleep period at baseline. Readings recorded in units of mmHg.
Measured: Baseline Night Average
Daytime Systolic Blood Pressure
Systolic blood pressure measured via automatic sphygmomanometer every 20 minutes during the daytime period at baseline. Readings recorded in units of mmHg.
Measured: Baseline Daytime Average
Daytime Diastolic Blood Pressure
Diastolic blood pressure measured via automatic sphygmomanometer every 20 minutes during the daytime period at baseline. Readings recorded in units of mmHg.
Measured: Baseline Daytime Average
Change in Systolic Blood Pressure Across Sleep Period
Change in systolic blood pressure per hour of scheduled sleep period measured via automatic sphygmomanometer every 30 minutes across each of the scheduled sleep periods while participants stayed 7-nights and days in the laboratory. Sleep was scheduled to occur at varied times across the entire circadian cycle so that the effects of the circadian cycle can be ignored (i.e., averaged out).
Measured: 7 days in the laboratory
Change in Diastolic Blood Pressure Across Sleep Period
Change in diastolic blood pressure per hour of scheduled sleep period measured via automatic sphygmomanometer every 30 minutes across each of the scheduled sleep periods while participants stayed 7-nights and days in the laboratory. Sleep was scheduled to occur at varied times across the entire circadian cycle so that the effects of the circadian cycle can be ignored (i.e., averaged out).
Measured: 7 days in the laboratory
Circadian Amplitude of Systolic Blood Pressure When Awake
Systolic blood pressure was assessed manually via sphygmomanometry during each scheduled wakefulness period while participants stayed 7-nights and days in the laboratory. Behaviors during wakefulness were standardized and scheduled to occur across the entire circadian cycle. Any systematic circadian rhythmicity was assessed by analysis of variance which revealed the underlying amplitude of the circadian rhythm of systolic blood pressure while controlling for (averaging out) any ongoing behaviors.
Measured: 7 days in the laboratory
Circadian Amplitude of Diastolic Blood Pressure When Awake
Diastolic blood pressure was assessed manually via sphygmomanometry during each scheduled wakefulness period while participants stayed 7-nights and days in the laboratory. Behaviors during wakefulness were standardized and scheduled to occur across the entire circadian cycle. Any systematic circadian rhythmicity was assessed by analysis of variance which revealed the underlying amplitude of the circadian rhythm of diastolic blood pressure while controlling for (averaging out) any ongoing behaviors.
Measured: 7 days in the laboratory

Timeline

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

1 Dec 201831 Dec 2024

First posted15 Jun 2018
Study start1 Dec 2018
Primary completion31 Dec 2024
Study completion31 Dec 2024

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 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: Basic science
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 30 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03558893
Sponsor's protocol ID: IRB 16803
Other IDs: R35HL155681
Status last verified: Jun 2026
First submitted: 5 Jun 2018
Last updated: 20 Jul 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
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

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Study at a glance

From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Sleep and Circadian Mechanisms Contributing to Nocturnal Non-dipping Blood Pressure
ClinicalTrials.gov ID: NCT03558893
Acronym / sponsor ID: IRB 16803
Conditions: Hypertension, Cardiovascular Risk Factor
Keywords: circadian rhythm
Study type: Interventional
Recruitment status: Completed
Enrolment: 30 participants (actual)
Lead sponsor: Oregon Health and Science UniversityUniversity, hospital or other
Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
Study start: 1 Dec 2018 (actual)
Primary completion: 31 Dec 2024 (actual)
Study completion: 31 Dec 2024 (actual)
First posted: 15 Jun 2018 (actual)
Results: Posted 16 Jun 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

By studying standardized behaviors and regulators of BP during sleep and behavioral stresses across all circadian phases, this protocol will allow us specifically to:

To determine if poor sleep, while controlling for circadian phase, contributes to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.
To determine if reduced BP responses to standardized behavioral changes across the day and night contribute to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.
To determine if reduced circadian amplitude of BP contributes to the higher overall BP and reduced nocturnal drop in BP in Blacks compared to Whites.

Study design

Primary purpose: Basic science
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
White Adults	Other	Behavioral: Forced DesynchronyWhite adults aged 30-60 with a BMI of 18.5<BMI<40 kg/m2 who are non-smokers (≥1 year), not on prescription medications (except oral contraceptives), and have had no recent shift work or major travel. Mild, unmanaged hypertension (below 160/100) and renal disease are allowed.
Black Adults	Other	Behavioral: Forced DesynchronyBlack adults aged 30-60 with a BMI of 18.5<BMI<40 kg/m2 who are non-smokers (≥1 year), not on prescription medications (except oral contraceptives), and have had no recent shift work or major travel. Mild, unmanaged hypertension (below 160/100) and renal disease are allowed.

Who may qualify

Ages: 30 to 60 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (3 listed)

Self-identified Black or White
'normotensive' (resting systolic blood pressure (SBP) <140/90 mmHg) or uncomplicated stage 1 'hypertensive' (systolic BP between 140 and 160 mmHg or a diastolic (DBP) between 90 and 100 mmHg).
free of all prescription and non-prescription drugs (including caffeine, nicotine, alcohol and herbal medications)

Key exclusion criteria (8 listed)

Currently treated with pharmacologic agents for hypertension
Blood pressure >160/100 mmHg
Smoked within the last year
Regular night work or rotating shift work for the three months prior to the study
Travel across more than three time zones during the three months prior to the study.

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
Forced DesynchronyParticipants will complete a 7-day circadian study protocol with numerous repeated blood pressure and other cardiovascular measures across the circadian cycle. 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.	Behavioural	Black Adults, White Adults

Primary outcome

Nighttime Systolic Blood Pressure
Time frame: Baseline Night Average
Systolic blood pressure measured via automatic sphygmomanometer every 30 minutes during sleep period at baseline. Readings recorded in units of mmHg.
Nighttime Diastolic Blood Pressure
Time frame: Baseline Night Average
Diastolic blood pressure measured via automatic sphygmomanometer every 30 minutes during sleep period at baseline. Readings recorded in units of mmHg.
Daytime Systolic Blood Pressure
Time frame: Baseline Daytime Average
Systolic blood pressure measured via automatic sphygmomanometer every 20 minutes during the daytime period at baseline. Readings recorded in units of mmHg.
Daytime Diastolic Blood Pressure
Time frame: Baseline Daytime Average
Diastolic blood pressure measured via automatic sphygmomanometer every 20 minutes during the daytime period at baseline. Readings recorded in units of mmHg.
Change in Systolic Blood Pressure Across Sleep Period
Time frame: 7 days in the laboratory
Change in systolic blood pressure per hour of scheduled sleep period measured via automatic sphygmomanometer every 30 minutes across each of the scheduled sleep periods while participants stayed 7-nights and days in the laboratory. Sleep was scheduled to occur at varied times across the entire circadian cycle so that the effects of the circadian cycle can be ignored (i.e., averaged out).
Change in Diastolic Blood Pressure Across Sleep Period
Time frame: 7 days in the laboratory
Change in diastolic blood pressure per hour of scheduled sleep period measured via automatic sphygmomanometer every 30 minutes across each of the scheduled sleep periods while participants stayed 7-nights and days in the laboratory. Sleep was scheduled to occur at varied times across the entire circadian cycle so that the effects of the circadian cycle can be ignored (i.e., averaged out).
Circadian Amplitude of Systolic Blood Pressure When Awake
Time frame: 7 days in the laboratory
Systolic blood pressure was assessed manually via sphygmomanometry during each scheduled wakefulness period while participants stayed 7-nights and days in the laboratory. Behaviors during wakefulness were standardized and scheduled to occur across the entire circadian cycle. Any systematic circadian rhythmicity was assessed by analysis of variance which revealed the underlying amplitude of the circadian rhythm of systolic blood pressure while controlling for (averaging out) any ongoing behaviors.
Circadian Amplitude of Diastolic Blood Pressure When Awake
Time frame: 7 days in the laboratory
Diastolic blood pressure was assessed manually via sphygmomanometry during each scheduled wakefulness period while participants stayed 7-nights and days in the laboratory. Behaviors during wakefulness were standardized and scheduled to occur across the entire circadian cycle. Any systematic circadian rhythmicity was assessed by analysis of variance which revealed the underlying amplitude of the circadian rhythm of diastolic blood pressure while controlling for (averaging out) any ongoing behaviors.

Results and safety

Results posted to the registry on 16 Jun 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
White Adults	25	19
Black Adults	5	5

Primary outcome: Nighttime Systolic Blood Pressure

Time frame: Baseline Night Average. Mean (Standard Error). Unit: mmHg

Measure	White Adults n = 19	Black Adults n = 5
Value	101.6 (2.1)	92.4 (4.0)

Population analysed: All participants who completed the in-laboratory study are included.

Primary outcome: Nighttime Diastolic Blood Pressure

Time frame: Baseline Night Average. Mean (Standard Error). Unit: mmHg

Measure	White Adults n = 19	Black Adults n = 5
Value	60.5 (1.4)	59.0 (1.4)

Population analysed: All participants who completed the in-laboratory study are included.

Primary outcome: Daytime Systolic Blood Pressure

Time frame: Baseline Daytime Average. Mean (Standard Error). Unit: mmHg

Measure	White Adults n = 19	Black Adults n = 5
Value	116.6 (8.6)	120.5 (9.7)

Population analysed: All participants who completed the in-laboratory study are included.

Primary outcome: Daytime Diastolic Blood Pressure

Time frame: Baseline Daytime Average. Mean (Standard Error). Unit: mmHg

Measure	White Adults n = 19	Black Adults n = 5
Value	68.1 (6.5)	72.6 (7.2)

Population analysed: All participants who completed the in-laboratory study are included.

Adverse events

Time frame: From enrollment until end of follow-up (1 week after the in lab monitoring).. Other adverse events reported at 4% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
White Adults	0 of 25 (0%)	8 of 25 (32%)	0 of 25
Black Adults	0 of 5 (0%)	4 of 5 (80%)	0 of 5

Limitations and caveats (from the sponsor): 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. While differences between White and Black participants were underpowered, in additional analyses we will examine effect of lifetime stress, as well as overall group circadian physiological responses to experimental conditions.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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. This study is not recruiting at the moment.

Steven A Shea, PhD principal investigator

Ore

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

Questions about this trial

What is this clinical trial studying?

A study testing Forced Desynchrony in people with Hypertension and Cardiovascular Risk Factor, 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 8 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 20 Jul 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 16 Jun 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?

Nighttime Systolic Blood Pressure (time frame: Baseline Night Average). The study lists 8 primary outcomes in all. 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 NCT03558893.

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 20 Jul 2026.