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Mechanisms of Refractory Hypertension (High and Low Salt Diet)

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ClinicalTrials.gov Identifier: NCT02357017
Recruitment Status : Withdrawn (Change in priority of interventional protocols)
First Posted : February 6, 2015
Last Update Posted : June 12, 2020
Sponsor:
Information provided by (Responsible Party):
David Calhoun, University of Alabama at Birmingham

Tracking Information
First Submitted Date  ICMJE January 22, 2015
First Posted Date  ICMJE February 6, 2015
Last Update Posted Date June 12, 2020
Study Start Date  ICMJE February 2015
Actual Primary Completion Date January 31, 2020   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: February 2, 2015)
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.
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE Not Provided
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Mechanisms of Refractory Hypertension (High and Low Salt Diet)
Official Title  ICMJE Mechanisms of Refractory Hypertension (High and Low Salt Diet)
Brief 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 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 Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Condition  ICMJE Hypertension
Intervention  ICMJE Dietary Supplement: NaCl tablets
Study Arms  ICMJE
  • Active Comparator: Low salt diet
    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.
    Intervention: Dietary Supplement: NaCl tablets
  • Active Comparator: High salt diet
    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.
    Intervention: Dietary Supplement: NaCl tablets
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Withdrawn
Actual Enrollment  ICMJE
 (submitted: June 10, 2020)
0
Original Estimated Enrollment  ICMJE
 (submitted: February 2, 2015)
40
Actual Study Completion Date  ICMJE January 31, 2020
Actual Primary Completion Date January 31, 2020   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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
Sex/Gender  ICMJE
Sexes Eligible for Study: Male
Ages  ICMJE 19 Years to 80 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Not Provided
Removed Location Countries United States
 
Administrative Information
NCT Number  ICMJE NCT02357017
Other Study ID Numbers  ICMJE B000502641
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party David Calhoun, University of Alabama at Birmingham
Study Sponsor  ICMJE University of Alabama at Birmingham
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Principal Investigator: David A. Calhoun, MD Cardiology Department - University of Alabama at Birmingham
PRS Account University of Alabama at Birmingham
Verification Date June 2020

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP