Sleep and Circadian Contributions to Nighttime Blood Pressure

Study Overview
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Brief Summary
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Broadly, this study (SCN-BP) seeks to examine sleep and circadian factors that contribute to blood pressure levels at night.

Detailed Description
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SCN-BP is imbedded in a parent grant titled Improving the Detection of Hypertension (IDH-MEGA) and examines a variety of sleep (e.g., sleep duration, timing, and the presence of sleep disorder) and circadian factors in Aims 1 and 2. In Aim 3, the investigators will conduct a 30-hour constant routine protocol to directly examine endogenous circadian and blood pressure rhythms.

Official Title
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Sleep and Circadian Contributions to Nighttime Blood Pressure

Conditions
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Sleep, Circadian Rhythm, Blood Pressure, Hypertension

Intervention / Treatment
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* Other: Constant Routine Protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant in the parent grant (IDH-MEGA) Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Constant Routine Protocol<br>Participants complete a 30-hour constant routine protocol to directly examine markers of endogenous circadian rhythms. In a constant routine protocol, participants remain in a dimly lit room (<10 lux), in a semi-recumbent posture, remain awake, and consume iso-caloric snacks. Saliva samples are collected and core body temperature and blood pressure are measured. | Other: Constant Routine Protocol<br>* A constant routine protocol is used to directly examine markers of circadian rhythmicity (e.g., melatonin and core body temperature). A constant routine protocol requires an individual to remain in a dimly lit room, in a constant semi-recumbent posture, and remain awake for more than 24 hours. It is one of two gold-standard research protocols for examining circadian rhythms in humans.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Melatonin | Melatonin levels obtained from saliva samples | Hourly samples obtained over 30 hours | 
| Change in Core body temperature | Core body temperature | Continuous measurements over 30 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Blood pressure | Systolic and diastolic blood pressure obtained using an ambulatory blood pressure monitor | Measurements obtained every 30 minutes over 30 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sleep, circadian rhythm, circadian misalignment, nocturnal hypertension, non-dipping blood pressure