Stress, Salt Excretion, and Nighttime Blood Pressure (SABRE)

Psychological Stress, and Circadian Patterns of Sodium Excretion and Blood Pressure

The study will examine urinary sodium excretion induced by psychological stress and its diurnal pattern as a novel biological mechanism that may underlie an abnormal diurnal pattern of blood pressure. The study will test the hypotheses that lower stress-induced sodium excretion is associated with an abnormal diurnal pattern of sodium excretion, and that an abnormal diurnal pattern of sodium excretion is associated with an abnormal diurnal pattern of blood pressure.

Primary Aim 1: To examine the association between urinary sodium excretion after provoked psychological stress and the diurnal pattern of sodium excretion.

Primary Aim 2: To examine the association between the diurnal pattern of sodium excretion and the diurnal pattern of BP.

Secondary Aim: To examine whether the association between urinary sodium excretion after provoked stress and the diurnal pattern of sodium excretion is modified by ecological momentary levels of perceived stress, experienced during the daytime period.

Exploratory Aim: To determine the socio-demographic, behavioral, and psychological traits, chronic stress, and biological stress-related factors that are associated with lower stress-induced sodium excretion. Identification of these factors will help determine who is at risk for having a differential sodium excretion response to psychological stress.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Psychological Stress
• Intervention / Treatment: Behavioral: Psychological Stress Intervention

Detailed Description

Blood pressure (BP) has a diurnal rhythm; it is normally highest during the daytime period and lowest during the nighttime period (BP dipping). The diurnal pattern of BP over a 24-hour period can be assessed using ambulatory BP monitoring (ABPM). Evidence indicates that an abnormal diurnal pattern of BP on ABPM, defined by reduced BP dipping or elevated nighttime BP, is associated with an increased risk of cardiovascular disease (CVD) events.

Psychological stress occurs when an individual perceives that the environmental demands exceed his/her adaptive capacity. An individual's response to events that are representative of this overload, such as perceived stress and negative affect including anger, hostility, depression, vital exhaustion, and symptoms of posttraumatic stress disorder, are associated with reduced BP dipping and/or higher nighttime BP. Exposure to environmental factors which tax an individual's ability to cope, including lower socioeconomic status, job strain, and perceived racism, are also associated with reduced BP dipping and/or higher nighttime BP. This study will examine the disruption of the normal diurnal pattern of sodium excretion by psychological stress as a novel biological mechanism underlying an abnormal diurnal pattern of BP.

The study will be conducted both in the laboratory and in the naturalistic environment with a multi-ethnic sample of 211 adult community participants from upper Manhattan who do not have a history of CVD, diabetes, chronic kidney disease, or another major medical condition and are not taking antihypertensive medication. During a laboratory visit, urinary sodium excretion in response to mental stress tasks will be examined.

• Study Type: Interventional
• Enrollment (Actual): 323
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10032
      • Columbia University Medical Center - Shimbo Hypertension Lab

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 21 years or older
• Screening mean blood pressure less than or equal to 160/105 mm Hg

Exclusion Criteria:

• History of overt cardiovascular disease (coronary heart disease, stroke, peripheral arterial disease, heart failure, permanent or recurring arrhythmia)
• History of secondary hypertension
• History of other major medical condition (cancer, rheumatologic diseases, immunologic diseases, etc.)
• Taking anti-hypertensive medications or other medications that are known to substantially affect blood pressure (e.g. steroids, chronic anti-inflammatory medications, etc.)
• Non-English speaking

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Psychological Stress; All enrolled participants who attended the laboratory visit underwent stress-inducing tasks (psychological stress) using validated research tools. Participants performed a 5-minute computer Stroop Color Test and a 5-minute verbal Mental Arithmetic Task. The research assistant asked the participant to work as quickly and accurately as possible for both tasks. Then during the ambulatory period, the participants underwent 24-hour ambulatory blood pressure monitoring during which urine was collected during the awake and asleep periods. Further, 5 ecological momentary assessment (EMA) ratings of perceived stress and negative affect (angry/hostile, aggravated/irritated, anxious/tense/nervous, and sad/blue/depressed) were collected during the awake period.

Behavioral: Psychological Stress Intervention; All enrolled participants who attended the laboratory visit underwent stress-inducing tasks (psychological stress) using validated research tools. Participants performed a 5-minute computer Stroop Color Test and a 5-minute verbal Mental Arithmetic Task. The research assistant asked the participant to work as quickly and accurately as possible for both tasks.; Other Names: Provoked Psychological Stress

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratio of Awake-to-asleep Urinary Sodium Excretion Rate (Aim 1)		Over 24-hour ambulatory period
Systolic Blood Pressure Dipping (Aim 2)	Systolic blood pressure (SBP) dipping refers to the normal physiological decline in SBP during nighttime sleep. SBP dipping (%) was calculated as 100 * (mean awake SBP - mean asleep SBP) / (mean awake SBP).	Over 24-hour ambulatory period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Perceived Stress Level	This is to measure the ecological stress level for the awake period during which the participants' sodium excretion is monitored. A 10-point Visual Analog Scale (VAS) (0=Not at all, 5=Moderately, and 10=Extremely) was used to assess stress.	Over 24-hour ambulatory period
24-hour Sodium Excretion	Rate of sodium excretion, measured from urine collected from participants during the ambulatory period.	Over 24-hour ambulatory period
24-hour Potassium Excretion	Rate of potassium excretion, measured from urine collected from participants during the ambulatory period.	Over 24-hour ambulatory period
24-hour Creatinine Clearance	Rate of creatine clearance, measured from urine collected from participants during the ambulatory period.	Over 24-hour ambulatory period
Fractional Excretion of Sodium	Fractional excretion of sodium is the amount of sodium that leaves the body through urine compared to the amount filtered and reabsorbed by the kidney.	Over 24-hour ambulatory period
EMA Stress	10-point Ecological Momentary Assessment (EMA) measures self-reported stress through a questionnaire (0=Not at all, 5=Moderately, and 10=Extremely). Higher score indicates worse stress. The average EMA score over 5 time points in a 24-hour ambulatory period are reported.	Over 24-hour ambulatory period
EMA Anger	10-point Ecological Momentary Assessment (EMA) measures self-reported anger through a questionnaire (0=Not at all, 5=Moderately, and 10=Extremely). Higher score indicates worse anger. The average EMA score over 5 time points in a 24-hour ambulatory period are reported.	Over 24-hour ambulatory period
EMA Aggravation	10-point Ecological Momentary Assessment (EMA) measures self-reported aggravation/irritation through a questionnaire (0=Not at all, 5=Moderately, and 10=Extremely). Higher score indicates worse aggravation. The average EMA score over 5 time points in a 24-hour ambulatory period are reported.	Over 24-hour ambulatory period
EMA Anxiety	10-point Ecological Momentary Assessment (EMA) measures self-reported anxiety through a questionnaire (0=Not at all, 5=Moderately, and 10=Extremely). Higher score indicates worse anxiety. The average EMA score over 5 time points in a 24-hour ambulatory period are reported.	Over 24-hour ambulatory period
EMA Depressed	10-point Ecological Momentary Assessment (EMA) measures self-reported sadness/depression through a questionnaire (0=Not at all, 5=Moderately, and 10=Extremely). Higher score indicates worse depression. The average EMA score over 5 time points in a 24-hour ambulatory period are reported.	Over 24-hour ambulatory period

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Urinary Sodium Excretion Rate With Stress		Over 24-hour ambulatory period
Systolic Blood Pressure Dipping	Systolic blood pressure (SBP) dipping refers to the normal physiological decline in SBP during nighttime sleep. SBP dipping (%) was calculated as 100 * (mean awake SBP - mean asleep SBP) / (mean awake SBP).	Over 24-hour ambulatory period
Diastolic Blood Pressure Dipping	Diastolic blood pressure (DBP) dipping refers to the normal physiological decline in DBP during nighttime sleep. DBP dipping (%) was calculated as 100 * (mean awake DBP - mean asleep DBP) / (mean awake DBP).	Over 24-hour ambulatory period

Collaborators and Investigators

• Sponsor: Columbia University
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: Daichi Shimbo, MD, Professor of Medicine, Dept of Med Beh Cardiology

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2018
• Primary Completion (Actual): December 4, 2023
• Study Completion (Actual): December 4, 2023

Study Registration Dates

• First Submitted: August 9, 2018
• First Submitted That Met QC Criteria: August 16, 2018
• First Posted (Actual): August 17, 2018

Study Record Updates

• Last Update Posted (Actual): May 11, 2025
• Last Update Submitted That Met QC Criteria: April 28, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Non-Dipping Blood Pressure
• Additional Relevant MeSH Terms: Behavioral Symptoms; Stress, Psychological
• Other Study ID Numbers: AAAS0154; 1R01HL137818-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No