HypertensionNCT02357017
Mechanisms of Refractory Hypertension (High and Low Salt Diet)
A study testing NaCl tablets in people with Hypertension, run by University of Alabama at Birmingham.
Trial summary
The purpose of the study is to test the hypothesis that persistent fluid retention and high sympathetic output contributes to the development of refractory hypertension (HTN). The investigators will determine, in a cross-over assessment of high and low salt diets, if dietary sodium restriction reduces 24-hr ambulatory… Read more about this study
- Who is it for?
- Ages 19 to 80 years, men only
- Conditions the study is for
- Hypertension
- What is being tested?
- NaCl tablets
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- Feb 2015to 31 Jan 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 19 to 80 years
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult subjects ≥ 19 years of age
- Refractory hypertension defined as office BP > 140/90 that is uncontrolled with at least 5 different classes of antihypertensive medications
- Self-reported adherence >80% with prescribed antihypertensive medications
Who cannot join
- Severe hypertension (office BP >160/100 mm Hg)
- History of congestive heart failure (ejection fraction of <40%)
- Chronic kidney disease (creatinine clearance <60 ml/min)
- History of cardiovascular disease (stroke, TIA, myocardial infarction, or revascularization procedure)
- White coat hypertension defined as office BP >140/90 mm Hg and ambulatory daytime BP <135/85 mm Hg
- Pregnant or nursing women
About this study
The purpose of the study is to test the hypothesis that persistent fluid retention and high sympathetic output contributes to the development of refractory hypertension (HTN). The investigators will determine, in a cross-over assessment of high and low salt diets, if dietary sodium restriction reduces 24-hr ambulatory BP in patients with refractory HTN. Moreover, the investigators will determine if dietary sodium restriction lessens the severity of obstructive sleep apnea (OSA) in patients with refractory HTN.
Read the detailed description
We are proposing a unique phenotype of antihypertensive treatment failure that we refer to as refractory HTN. We have come to feel that while resistant (RHTN) represents a broad phenotype with multiple and overlapping etiologies of treatment resistance, there is a unique subset of patients who never achieve BP control in spite of maximal therapy. In a recently published retrospective analysis of our clinic experience, we found that patients with refractory HTN comprised about 10% of patients referred to us for RHTN.
A large number of intervention studies have verified the benefit of dietary salt restriction to reduce BP. We made such an assessment in a prospective, randomized, cross-over comparison of high- and low salt diets in 12 patients with confirmed RHTN. The average reduction in BP going from high to the low salt diet was 23/10 mmHg in the clinic and 20/10 mmHg during 24-hr ambulatory BP monitoring. These dramatic results demonstrated that patients with RHTN are exquisitely salt-sensitive and highlight the degree of BP reduction that can be accomplished with meaningful salt restriction. However, we are proposing the novel hypothesis that refractory HTN is mechanistically unique from RHTN in that it is not secondary to recalcitrant fluid retention.
Determining an association between dietary salt restriction and severity of obstructive sleep apnea (OSA) would potentially help us to find new therapies guided towards achieving better control of BP in patients with refractory HTN. We will investigate the effect of dietary salt intake on severity of OSA vascular function in patients with refractory HTN by doing vascular studies (pulse wave analysis/velocity, calculating thoracic impedance)).
- Conditions
- Hypertension
- Being tested
- NaCl tablets
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NaCl tabletsDietary supplement
| Study group | Role | What they receive |
|---|---|---|
| Low salt diet | Active comparator | The low-salt meals will be formulated to provide 50 mmol of sodium per day. Two diets with different caloric amounts (2000 or 2500) will be available. Receives: Dietary Supplement: NaCl tablets |
| High salt diet | Active comparator | High dietary salt intake, NaCl tablets (6 grams/day) will added to the subject's study diet in order to increase dietary sodium intake to >250 mmol/day. Receives: Dietary Supplement: NaCl tablets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in 24-hour ambulatory systolic blood pressure (BP).
The mean change in blood pressure for each group after receiving 4 weeks of either a low salt diet compared to High dietary salt intake. The low-salt meals will be formulated to provide 50 mmol of sodium per day. Two diets with different caloric amounts (2000 or 2500) will be available. High dietary salt intake, NaCl tablets (6 grams/day) will added to the subject's study diet in order to increase dietary sodium intake to >250 mmol/day.
Measured: baseline to 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2015 (estimated)
- Study startFeb 2015
- Primary completion31 Jan 2020
- Study completion31 Jan 2020
Why it stopped: Change in priority of interventional protocols
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Calhoun, University of Alabama at Birmingham
- Investigators
- David A. Calhoun, MD, Principal investigator, Cardiology Department - University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02357017
- Sponsor's protocol ID
- B000502641
- Status last verified
- Jun 2020
- First submitted
- 22 Jan 2015
- Last updated
- 12 Jun 2020
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jun 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mechanisms of Refractory Hypertension (High and Low Salt Diet)
- ClinicalTrials.gov ID
- NCT02357017
- Acronym / sponsor ID
- B000502641
- Conditions
- Hypertension
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Change in priority of interventional protocols
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of Alabama at BirminghamUniversity, hospital or other
- Study start
- Feb 2015
- Primary completion
- 31 Jan 2020 (actual)
- Study completion
- 31 Jan 2020 (actual)
- First posted
- 6 Feb 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to test the hypothesis that persistent fluid retention and high sympathetic output contributes to the development of refractory hypertension (HTN). The investigators will determine, in a cross-over assessment of high and low salt diets, if dietary sodium restriction reduces 24-hr ambulatory BP in patients with refractory HTN. Moreover, the investigators will determine if dietary sodium restriction lessens the severity of obstructive sleep apnea (OSA) in patients with refractory HTN.
Detailed description
We are proposing a unique phenotype of antihypertensive treatment failure that we refer to as refractory HTN. We have come to feel that while resistant (RHTN) represents a broad phenotype with multiple and overlapping etiologies of treatment resistance, there is a unique subset of patients who never achieve BP control in spite of maximal therapy. In a recently published retrospective analysis of our clinic experience, we found that patients with refractory HTN comprised about 10% of patients referred to us for RHTN.
A large number of intervention studies have verified the benefit of dietary salt restriction to reduce BP. We made such an assessment in a prospective, randomized, cross-over comparison of high- and low salt diets in 12 patients with confirmed RHTN. The average reduction in BP going from high to the low salt diet was 23/10 mmHg in the clinic and 20/10 mmHg during 24-hr ambulatory BP monitoring. These dramatic results demonstrated that patients with RHTN are exquisitely salt-sensitive and highlight the degree of BP reduction that can be accomplished with meaningful salt restriction. However, we are proposing the novel hypothesis that refractory HTN is mechanistically unique from RHTN in that it is not secondary to recalcitrant fluid retention.
Determining an association between dietary salt restriction and severity of obstructive sleep apnea (OSA) would potentially help us to find new therapies guided towards achieving better control of BP in patients with refractory HTN. We will investigate the effect of dietary salt intake on severity of OSA vascular function in patients with refractory HTN by doing vascular studies (pulse wave analysis/velocity, calculating thoracic impedance)).
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Low salt diet | Active comparator | Dietary Supplement: NaCl tabletsThe low-salt meals will be formulated to provide 50 mmol of sodium per day. Two diets with different caloric amounts (2000 or 2500) will be available. |
| High salt diet | Active comparator | Dietary Supplement: NaCl tabletsHigh dietary salt intake, NaCl tablets (6 grams/day) will added to the subject's study diet in order to increase dietary sodium intake to >250 mmol/day. |
Who may qualify
- Ages
- 19 to 80 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Adult subjects ≥ 19 years of age
- Refractory hypertension defined as office BP > 140/90 that is uncontrolled with at least 5 different classes of antihypertensive medications
- Self-reported adherence >80% with prescribed antihypertensive medications
Key exclusion criteria (6 listed)
- Severe hypertension (office BP >160/100 mm Hg)
- History of congestive heart failure (ejection fraction of <40%)
- Chronic kidney disease (creatinine clearance <60 ml/min)
- History of cardiovascular disease (stroke, TIA, myocardial infarction, or revascularization procedure)
- White coat hypertension defined as office BP >140/90 mm Hg and ambulatory daytime BP <135/85 mm Hg
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NaCl tablets | Dietary supplement | High salt diet, Low salt diet |
Primary outcome
Change in 24-hour ambulatory systolic blood pressure (BP).
Time frame: baseline to 4 weeks
The mean change in blood pressure for each group after receiving 4 weeks of either a low salt diet compared to High dietary salt intake. The low-salt meals will be formulated to provide 50 mmol of sodium per day. Two diets with different caloric amounts (2000 or 2500) will be available. High dietary salt intake, NaCl tablets (6 grams/day) will added to the subject's study diet in order to increase dietary sodium intake to >250 mmol/day.
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jun 2020.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David A. Calhoun, MD principal investigator
Cardiology Department - University of Alabama at Birmingham
Questions about this trial
What is this clinical trial studying?
A study testing NaCl tablets in people with Hypertension, run by University of Alabama at Birmingham.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 12 Jun 2020. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in 24-hour ambulatory systolic blood pressure (BP). (time frame: baseline to 4 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jun 2020.