Timing of Sodium Intake and Nocturnal Sodium Excretion and Blood Pressure in Obese African Americans

  • STATUS
    Recruiting
  • End date
    Jul 31, 2024
  • participants needed
    55
  • sponsor
    University of Alabama at Birmingham
Updated on 24 July 2022
hypertension
Accepts healthy volunteers

Summary

Experimental data have shown that timing of sodium intake impacts diurnal patterns of sodium excretion. The purpose of this study is to test the hypothesis that the time of day for salt intake impacts (1) blood pressure rhythms and urinary sodium excretion and (2) circadian timing of factors responsible for blood pressure regulation and cardiometabolic health in obese individuals. These studies will address two aims. The first aim will test the hypothesis that limiting high salt intake prior to sleep increases day-night differences in blood pressure, improves timing of urinary sodium excretion, and improves metabolic risk factors. The second aim will test the hypothesis that limiting high salt intake prior to sleep preferentially improves rhythmicity in peripheral vs. central circadian clock factors linked to renal sodium handling. The proposed hypothesis-driven studies will determine how timing of sodium intake affects diurnal blood pressure and circadian timing of factors responsible for blood pressure control and metabolic health, with the ultimate goal of identifying novel strategies to treat nocturnal hypertension and metabolic disease in obesity.

Description

Timing of food intake affects a variety of pathophysiological systems. The Western diet, which is high in salt, also contributes to excess morbidity and mortality related to obesity and hypertension. Nocturnal hypertension frequently occurs in obesity and is recognized as an important consequence of hypertension risk, yet the mechanisms involved in this phenomenon are poorly understood. Experimental data from our group have shown that timing of sodium intake impacts diurnal patterns of sodium excretion. Further, we recently reported that high salt intake causes a shift in expression of circadian control genes in the kidney. Additional studies demonstrate that obese animals have an impaired response to a natriuretic stimulus.

Given the established contribution of high salt intake to obesity-dependent hypertension, particularly, nocturnal hypertension, we hypothesize that the time of day for salt intake impacts (1) blood pressure rhythms and urinary sodium excretion and (2) circadian timing of factors responsible for blood pressure regulation and cardiometabolic health in obese individuals. We will conduct a cross-over feeding study of 55 obese adults.

These studies will address two aims. The first aim will test the hypothesis that limiting high salt intake prior to sleep increases day-night differences in blood pressure, improves timing of urinary sodium excretion, and improves metabolic risk factors. We will monitor 24-hour blood pressure by ambulatory blood pressure monitoring to determine the role of timing of sodium intake on diurnal blood pressure patterns. Day- and night-time sodium excretion will be used to determine whether improvements in blood pressure are mediated by enhanced sodium excretion during the day. We will also assess the effects of timing of sodium intake on lipids, leptin, adiponectin, insulin sensitivity, inflammatory cytokines, and immune cell activation over 24 hours.

The second aim will test the hypothesis that limiting high salt intake prior to sleep preferentially improves rhythmicity in peripheral vs. central circadian clock factors linked to renal sodium handling. Circadian measures of plasma cortisol, dim light melatonin onset, and core body temperature (telemetry) will be used to assess the phase and amplitude of the core circadian clock. Circadian measures of peripheral clock genes in buccal cells and peripheral blood monocytes will be used to determine the phase and amplitude of the peripheral clock.

The proposed hypothesis-driven studies will determine how timing of sodium intake affects diurnal blood pressure and circadian timing of factors responsible for blood pressure control and metabolic health, with the ultimate goal of identifying novel strategies to treat nocturnal hypertension and metabolic disease in obesity

Details
Condition Obesity, Hypertension, Circadian Dysregulation, Salt; Excess
Treatment Oral sodium supplementation
Clinical Study IdentifierNCT04021355
SponsorUniversity of Alabama at Birmingham
Last Modified on24 July 2022

Eligibility

Yes No Not Sure

Inclusion Criteria

obese (BMI 30-50 kg/m2)
-45 years of age

Exclusion Criteria

evidence of kidney disease (eGFR < 60 ml/min/1.73m2 or abnormal urinalysis)
elevated BP (>150/90 mmHg [measured at screening in duplicate after 10min lying recumbent])
elevated fasting glucose (>126 g/dL on screening labs)
severe anemia (hemoglobin < 8 g/dL for women or < 9 g/dL for men)
significant psychiatric illness (as assessed by a validated screening form)
past or present drug or alcohol abuse (drug screen)
taking 2 or more BP medications or supplements on a regular basis
alcohol intake more than 2 drinks/day
pregnancy
women taking hormone replacement therapy, or post-menopausal women
shift worker
sleep disorders (such as sleep apnea assessed by Apnea Link)
major chronic disease (e.g., diabetes, lymphocyte disorders)
history of smoking or use of tobacco products within the past year
use of sleep medications, hypnotics, stimulants, or anti-depressants
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact

site

0/250

Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider

Loading...

Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 

 • 

Private

Reply by • Private
Loading...

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.
Loading...

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note