SleepSCN-BPNCT05656768
Sleep and Circadian Contributions to Nighttime Blood Pressure
A study testing Constant Routine Protocol in people with Sleep and Circadian Rhythm, run by University of Alabama at Birmingham at 1 site in United States.
Trial summary
Broadly, this study (SCN-BP) seeks to examine sleep and circadian factors that contribute to blood pressure levels at night. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Sleep, Circadian Rhythm, Blood Pressure
- What is being tested?
- Constant Routine Protocol
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,427 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jun 2023to 30 Dec 2028
- Phase
- Interventional
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participant in the parent grant (IDH-MEGA)
Who cannot join
- -
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
University of Alabama at Birmingham
Birmingham, Alabama, 35294-0017
About this study
Broadly, this study (SCN-BP) seeks to examine sleep and circadian factors that contribute to blood pressure levels at night.
Read the detailed description
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. Aims 1 and 2 are purely observation. The study design design described below pertains the intervention piece of this study (Aim 3).
- Conditions
- Sleep, Circadian Rhythm, Blood Pressure, Hypertension
- Being tested
- Constant Routine Protocol
- Keywords
- sleep, circadian rhythm, circadian misalignment, nocturnal hypertension, non-dipping blood pressure
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Constant Routine ProtocolOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Constant Routine Protocol | Experimental | 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. Receives: Other: Constant Routine Protocol |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Melatonin
Melatonin levels obtained from saliva samples
Measured: Hourly samples obtained over 30 hours
Change in Core body temperature
Core body temperature
Measured: Continuous measurements over 30 hours
Secondary outcomes (1)
Change in Blood pressure
Systolic and diastolic blood pressure obtained using an ambulatory blood pressure monitor
Measured: Measurements obtained every 30 minutes over 30 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Dec 2022
- Study start1 Jun 2023
- Primary completion30 Dec 2028 (estimated)
- Study completion30 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SleepStudies of the same condition, open and under way.
- More trials run by University of Alabama at BirminghamThe 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
- Masking
- None (open label)
- Enrolment
- 1,427 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Stephen Justin Thomas, PhD, University of Alabama at Birmingham
- Investigators
- Stephen J Thomas, PhD, Principal investigator, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05656768
- Sponsor's protocol ID
- IRB-300010042
- Acronym
- SCN-BP
- Status last verified
- Jan 2026
- First submitted
- 18 Nov 2022
- Last updated
- 29 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No