Sleep and Circadian Rhythm Study for High Blood Pressure

(SCN-BP Trial)

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Alabama at Birmingham

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

70 Participants Needed

Trial Summary

What is the purpose of this trial?

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

Do I need to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the Constant Routine Protocol treatment for high blood pressure?

Research shows that aligning blood pressure treatment with the body's natural circadian rhythms can improve blood pressure control, especially at night. This approach, known as chronotherapy, has been effective in optimizing the timing of medications to reduce cardiovascular risks, suggesting that treatments like the Constant Routine Protocol, which consider circadian rhythms, may also be beneficial. ^{1 2 3 4 5}

Is the Constant Routine Protocol safe for humans?

Research on the timing of blood pressure medications, which considers circadian rhythms, shows that taking these medications in the evening can improve safety by reducing adverse effects and improving kidney and heart health. No significant safety concerns have been reported in studies involving thousands of participants. ^{3 5 6 7 8}

How does the Constant Routine Protocol treatment for high blood pressure differ from other treatments?

The Constant Routine Protocol is unique because it focuses on stabilizing sleep and circadian rhythms, which are often disrupted in people with high blood pressure. Unlike traditional treatments that may involve medication, this approach aims to regulate blood pressure by addressing the body's natural 24-hour cycles. ^{2 4 5 9 10}

Research Team

Stephen J. Thomas, PhD

Principal Investigator

University of Alabama at Birmingham

Eligibility Criteria

This trial is for participants of the parent grant IDH-MEGA who are interested in understanding how sleep and their body's internal clock affect nighttime blood pressure.

Inclusion Criteria

You are already taking part in the main study called IDH-MEGA.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Constant Routine Protocol

Participants complete a 30-hour constant routine protocol to examine markers of endogenous circadian rhythms, including blood pressure, melatonin, and core body temperature measurements.

30 hours

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the constant routine protocol

4 weeks

Treatment Details

Interventions

• Constant Routine Protocol

Trial Overview The study is exploring how sleep patterns and circadian rhythms influence high blood pressure at night using a Constant Routine Protocol to monitor changes.

Participant Groups

Group I: Constant Routine Protocol Experimental Treatment 1 Intervention

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.

Who Is Running the Clinical Trial?

University of Alabama at Birmingham

Lead Sponsor

Trials

1,677

Recruited

2,458,000+

Findings from Research

In a study of 1720 adults, irregular sleep patterns, specifically a standard deviation of sleep duration greater than 90 minutes over a week, were linked to a higher prevalence of hypertension (HTN) and elevated blood pressure (BP) levels.

Participants without obstructive sleep apnea (OSA) who had significant sleep irregularity were found to have a 48% increased likelihood of having hypertension, highlighting the importance of consistent sleep duration for cardiovascular health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sleep irregularity and the association with hypertension and blood pressure levels: the ELSA-Brasil study. Parise, BK., Santos, RB., Mesas, AE., et al.[2023]

Blunted blood pressure decline during sleep is linked to a higher risk of cardiovascular events, highlighting the importance of managing blood pressure effectively at night.

Taking blood pressure medications like ACE inhibitors and ARBs in the evening rather than the morning can lead to better control of nighttime blood pressure and improve overall cardiovascular health, suggesting that aligning treatment with the body's natural rhythms (chronotherapy) is beneficial.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Circadian rhythms in blood pressure regulation and optimization of hypertension treatment with ACE inhibitor and ARB medications. Hermida, RC., Ayala, DE., Fernández, JR., et al.[2011]

The study analyzed blood pressure (BP) rhythms in 378 subjects, revealing that sleep-time hypertensive individuals have lower 24-hour and 12-hour BP rhythm amplitude and integrity compared to awake-time hypertensives, indicating a disorganized circadian rhythm.

This disorganization in BP rhythms among sleep-time hypertensives may be linked to increased cardiovascular risk, highlighting the importance of monitoring BP patterns during both awake and sleep periods.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blunting of circadian rhythms and increased acrophase variability in sleep-time hypertensive subjects. Perez-Lloret, S., Risk, M., Golombek, DA., et al.[2008]

In a study analyzing 26,170 ambulatory blood pressure monitoring (ABPM) recordings, it was found that 43% of patients, including those with normal blood pressure, exhibited non-dipping patterns, indicating a potential risk for cardiovascular issues.

Age and body mass index (BMI) were significant factors influencing blood pressure patterns, with older patients and those with a BMI over 30 showing higher rates of non-dipping, which could affect their overall cardiovascular health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ambulatory blood pressure monitoring profiles in a cross-sectional analysis of a large database of normotensive and true or suspected hypertensive patients. Araújo, S., Rouxinol-Dias, A., Mesquita-Bastos, J., et al.[2021]

Using arbitrary times for defining awake and sleep periods in hypertension studies does not significantly change the average blood pressure readings, but it can lead to substantial differences in individual measurements, especially during sleep.

In about 20% to 30% of subjects, the choice of time schedule can alter sleep blood pressure loads by more than 10%, indicating that using actual patient-reported times is crucial for accurate assessment in 24-hour blood pressure monitoring.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of actual versus arbitrary awake and sleep times on analyses of 24-h blood pressure. Peixoto Filho, AJ., Mansoor, GA., White, WB.[2009]

References

1. New Zealand pubmed.ncbi.nlm.nih.gov

Circadian variations in blood pressure : implications for chronotherapeutics. [2018]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Sleep irregularity and the association with hypertension and blood pressure levels: the ELSA-Brasil study. [2023]

3. United States pubmed.ncbi.nlm.nih.gov

Circadian rhythms in blood pressure regulation and optimization of hypertension treatment with ACE inhibitor and ARB medications. [2011]

4. England pubmed.ncbi.nlm.nih.gov

Blunting of circadian rhythms and increased acrophase variability in sleep-time hypertensive subjects. [2008]

5. Spain pubmed.ncbi.nlm.nih.gov

Ambulatory blood pressure monitoring profiles in a cross-sectional analysis of a large database of normotensive and true or suspected hypertensive patients. [2021]

6. England pubmed.ncbi.nlm.nih.gov

Systematic review and quality evaluation of published human ingestion-time trials of blood pressure-lowering medications and their combinations. [2021]

7. England pubmed.ncbi.nlm.nih.gov

Protocol for assessment of sleep quality and duration in the Treatment In Morning versus Evening (TIME) study: a randomised controlled trial using online patient-reported outcome measures. [2021]

8. United States pubmed.ncbi.nlm.nih.gov

Treatment of hypertension with chronotherapy: is it time of drug administration? [2018]

9. United States pubmed.ncbi.nlm.nih.gov

Quantitative analysis of the 24-hour blood pressure and heart rate patterns in young men. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Effects of actual versus arbitrary awake and sleep times on analyses of 24-h blood pressure. [2009]