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Completed

NCT Number: NCT03558893

Sleep and Circadian Mechanisms of 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.

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Key information

Conditions

Hypertension Cardiovascular Diseases Cardiovascular Risk Factor Vascular Diseases

Age range

30 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Oregon Health & Science University

Portland, Oregon, 97239, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • 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)

Exclusion criteria

  • 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.

Treatment and study plan

Forced Desynchrony

Behavioral

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.

Primary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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).

  6. 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).

  7. 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.

  8. 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.

Sponsors and collaborators

Lead sponsor

Oregon Health and Science University

Other

Collaborators

  • National Heart, Lung, and Blood Institute (NHLBI)

Registry information

Official study title

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

Important dates

Study start
2018
Primary completion
2024
Study completion
2024
First posted
Jun 15, 2018
Registry last updated
Jul 20, 2026

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

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

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

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