Circadian Mechanisms Underlying Non-Dipping Blood Pressure in Blacks

Sponsor

University of Alabama at Birmingham (Other)

Overall Status

Recruiting

CT.gov ID

NCT03934255

Collaborator

American Heart Association (Other)

Enrollment

Location

Arm

38.9

Anticipated Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

This study seeks to examine central and peripheral circadian mechanisms in Blacks with appropriately dipping systolic blood pressure (blood pressure that dips by at least 10%) compared with non-dipping systolic blood pressure (blood pressure that dips by less than 10%) using a constant routine protocol. Constant routine protocols are commonly used in the field of circadian biology to examine rhythms in biological processes while controlling the entraining effects of light, activity, and diet.

Condition or Disease	Intervention/Treatment	Phase
Circadian Rhythm Blood Pressure	Other: Constant Routine Protocol	N/A

Detailed Description

This study will enroll a total of 40 participants (n=20 non-dippers; n=20 dippers) to complete a 30-hour constant routine protocol. Participants will undergo baseline testing that includes anthropometric measurements, clinic blood pressure measurements, completion of self-report questionnaires on sleep and mood, be fitted with an ambulatory blood pressure monitor and actigraphy watch, and be provided with home sleep testing (HST) equipment.

Following completion of baseline assessment, eligible participants will be scheduled for the 30-hour constant routine protocol. The 30-hour constant routine protocol will allow for the hourly collection of saliva, collection of buccal cells every 4 hours, and constant monitoring of core body temperature, all of which are primary outcomes in the assessment of central and peripheral circadian clock markers. Amplitude and phase of these outcomes will be assessed in non-dippers versus dippers.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Intervention Model Description:

Constant routine protocol in Blacks with dipping and non-dipping blood pressureConstant routine protocol in Blacks with dipping and non-dipping blood pressure

Masking:

None (Open Label)

Primary Purpose:

Basic Science

Official Title:

Central and Peripheral Circadian Mechanisms Underlying Non-Dipping Blood Pressure in Blacks

Actual Study Start Date :

Jan 1, 2020

Anticipated Primary Completion Date :

Mar 31, 2023

Anticipated Study Completion Date :

Mar 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Constant Routine Protocol Participants will be kept in constant conditions for 30 hours to observe circadian physiology in the absence of light, physical activity, and meals.	Other: Constant Routine Protocol Constant routine protocols are used in circadian research to examine underlying circadian rhythms in the absence of light, activity, and meals

Arm

Intervention/Treatment

Experimental: Constant Routine Protocol

Participants will be kept in constant conditions for 30 hours to observe circadian physiology in the absence of light, physical activity, and meals.

Other: Constant Routine Protocol

Constant routine protocols are used in circadian research to examine underlying circadian rhythms in the absence of light, activity, and meals

Outcome Measures

Primary Outcome Measures

Melatonin phase [Melatonin phase during a 30-hour constant routine protocol]
Circadian phase of melatonin obtained from saliva
Melatonin amplitude [Melatonin amplitude during a 30-hour constant routine protocol]
Circadian amplitude of melatonin obtained from saliva
Core body temperature phase [Core body temperature phase during a 30-hour constant routine protocol]
Circadian phase of core body temperature recorded and transmitted wirelessly
Core body temperature amplitude [Core body temperature amplitude during a 30-hour constant routine protocol]
Circadian amplitude of core body temperature recorded and transmitted wirelessly
Buccal cell mRNA expression [Expression of Bmal1 and Period 3 during a 30-hour constant routine protocol]
Expression of Bmal1 and Period 3 obtained from buccal cell mRNA

Secondary Outcome Measures

Cortisol phase [Cortisol phase during a 30-hour constant routine protocol]
Circadian phase of cortisol obtained rom saliva
Cortisol amplitude [Cortisol amplitude during a 30-hour constant routine protocol]
Circadian amplitude of cortisol obtained rom saliva

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Black or African American race
Age 18 years or older

Exclusion Criteria:

Work alternating or night shifts
Pregnant or nursing
Current illicit drug use
History of severe mental illness
Medical conditions that would be contraindicated for a constant routine protocol
Take anti-hypertensive medications or beta-blockers
Severe obstructive sleep apnea

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	University of Alabama at Birmingham	Birmingham	Alabama	United States	35294-0017

Sponsors and Collaborators

University of Alabama at Birmingham
American Heart Association

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

Stephen Justin Thomas, PhD, Assistant Professor, University of Alabama at Birmingham

ClinicalTrials.gov Identifier:

NCT03934255

Other Study ID Numbers:

IRB-300003266

First Posted:

May 1, 2019

Last Update Posted:

Mar 22, 2022

Last Verified:

Mar 1, 2022

Individual Participant Data (IPD) Sharing Statement:

Undecided

Plan to Share IPD:

Undecided

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Study Results

No Results Posted as of Mar 22, 2022