ObesityNCT04021355
Timing of Sodium Intake and Nocturnal Sodium Excretion and Blood Pressure in Obese African Americans
A study testing Oral sodium supplementation in people with Obesity and Hypertension, run by University of Alabama at Birmingham at 1 site in United States.
Trial 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… Read more about this study
- Who is it for?
- Ages 25 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Hypertension, Circadian Dysregulation
- What is being tested?
- Oral sodium supplementation
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 61 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Nov 2020to 31 Jul 2025
- 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 25 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- obese (BMI 30-50 kg/m2)
- 25-45 years of age
Who cannot join
- 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)
Show all 15Show fewer
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Timing of Sodium Intake and Nocturnal Sodium Excretion and Blood Pressure in Obese
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.
Read the detailed 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
- Conditions
- Obesity, Hypertension, Circadian Dysregulation, Salt; Excess
- Being tested
- Oral sodium supplementation
- Medical subject headings
- Obesity, Hypertension, Chronobiology Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oral sodium supplementationOther
Participants will receive dietary sodium supplementation in the form of tablets to be taken either with breakfast or dinner.
| Study group | Role | What they receive |
|---|---|---|
| Early Sodium | Experimental | Early sodium load: participants will consume a standardized diet providing 2.3 g of sodium per day for 7 days (run-in period), after which they will continue to consume the standardized diet for 9 days and in addition will take 2 g of sodium in the form of salt tablets with breakfast each day. Receives: Other: Oral sodium supplementation |
| Late Sodium | Experimental | Late sodium load: participants will consume a standardized diet providing 2.3 g of sodium per day for 7 days (run-in period), after which they will continue to consume the standardized diet for the next 9 days and in addition will take 2 g of sodium with dinner each day. Receives: Other: Oral sodium supplementation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sleep Systolic Blood Pressure
Systolic blood pressure measured during sleep by 24-hour ambulatory blood pressure monitor starting on the 8th day of consuming the standarized diet plus chicken-based broth
Measured: On the 8th day of consuming the standarized diet plus chicken-based broth
Secondary outcomes (10)
24-hour Urinary Sodium Excretion
Urinary sodium excretion measured in study arms by 24-hour urine collection starting on the 9th day of consuming the standarized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Concentrations of Plasma Melatonin
Plasma melatonin concentrations measured in blood samples collected every 2 hours for 24 hours starting on the 9th day of consuming the standarized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Concentrations of Plasma Cortisol
Plasma cortisol concentrations measured in study participants every 2 hours for 24 hours starting on the 9th day of consuming the standarized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Concentrations of Plasma Endothelin 1
Plasma endothelin 1 concentrations measured every 2 hours for 24 hours starting on the 9th day of consuming the standarized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Concentrations of Plasma Aldosterone
Plasma aldosterone concentrations measured every 2 hours for 24 hours starting on the 9th day of consuming the standarized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Core Body Temperature
Core Body Temperature measured using BodyCap On the 8th day of consuming the standardized diet plus chicken-based broth
Measured: On the 8th day of consuming the standardized diet plus chicken-based broth
Timing of Plasma Melatonin Increase Under Dim-light Conditions (Dim-light Melatonin Onset)
Timing of melatonin increase based on every 2-hour blood draws during the 24 hour admission on the 9th day of consuming the standardized diet plus chicken-based broth
Measured: On the 9th day of consuming the standardized diet plus chicken-based broth
Peripheral Blood Monocyte Clock Gene (CLOCK, Bmal1, per1, per2, Rev-erb-alpha, cry1, cry2) Expression
Timing of clock gene expression change based on every 2-hour blood draws during the 24 hour admission on the 9th day of consuming the standardized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Concentrations of Plasma Cytokine (TNA-alpha, IL-1, IL-6, IL-12, IL-17, IL-18, IL-23, IL-10, TGB-beta)
Changes in plasma cytokines based on every 2-hour blood draws during the 24 hour admission on the 9th day of consuming the standardized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Flow Cytometric Analysis of Circulating Immune Cells (CD3+, CD4+, CD8+, CD14+, CD45+)
Change in circulating immune cell proportions based on every 2-hour blood draws during the 24 hour admission on the 9th day of consuming the standardized diet plus chicken-based broth
Measured: On the 9th day of consuming the standarized diet plus chicken-based broth
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2019
- Study start14 Nov 2020
- Primary completion14 Jun 2025
- Study completion31 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for ObesityStudies 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
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 61 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Principal investigator, Orlando M. Gutierrez, MD, MMSc, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04021355
- Sponsor's protocol ID
- IRB-300003394
- Other IDs
- R01HL144716
- Status last verified
- Jul 2026
- First submitted
- 11 Jul 2019
- Last updated
- 20 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided