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Dietary Counseling or Potassium Supplement to Increase Potassium Intake in Patients With High Blood Pressure

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ClinicalTrials.gov Identifier: NCT03809884
Recruitment Status : Not yet recruiting
First Posted : January 18, 2019
Last Update Posted : January 18, 2019
Sponsor:
Information provided by (Responsible Party):
Ottawa Hospital Research Institute

Brief Summary:

High blood pressure is the leading cause of cardiovascular disease worldwide. Many medicines are available to lower blood pressures successfully, as well as many non-medical options, such as dietary changes. Some effective dietary changes include decreasing sodium and increasing potassium in the diet. A lot of focus has been on sodium intake yet; potassium intake in the diet remains low amongst adult Canadians. Excellent data exist in the published research reporting that increasing potassium intake, either as diet or even as supplements, reduces blood pressure and reduces risk of cardiovascular outcomes such as stroke.

The overall purpose of this study is to reveal the most effective way of increasing potassium, amongst participants with high blood pressure whose existing intake of potassium is low. In the first stage, participants with high blood pressure and proven low potassium intake will receive dietary counselling. If after 4 weeks, there has not been a desired increase in potassium intake, the patients will be prescribed an additional potassium supplement.


Condition or disease Intervention/treatment Phase
Hypertension Behavioral: Dietary Counselling Drug: Potassium Citrate Phase 3

Detailed Description:

High blood pressure is the leading cause of cardiovascular disease worldwide, including in Canada. The prevalence of high blood pressure is steadily rising, with growing and ageing population. Many medicines are available to decrease blood pressures successfully, as well as many non-medical options, such as dietary changes and exercise. There is a marked preference amongst patients, reiterated in a recent Hypertension Canada report, for more research into methods for controlling blood pressure without medicines or to reduce the burden of taking many pills to control high blood pressure. Indeed, effective options do exist, especially with diet, specifically decreasing sodium and increasing potassium in diet. Both these recommendations are also made by organizations worldwide including the World Health Organization as well as Hypertension Canada. Though a lot of focus has been on sodium intake in the public health outreach, even the potassium intake in diet remains woefully low amongst adult Canadians. Excellent data exist in the published research reporting that increasing potassium intake, either as diet or even as supplements, reduces blood pressure and reduces risk of cardiovascular outcomes such as stroke. The advice most often provided is to 'eat more fruits and vegetables' which does not get translated into concrete change.

The Investigators propose to do a clinical trial in two stages (as an adaptive trial design). In the first stage, participants with high blood pressure and proven low potassium intake (measured on the basis of collecting urine for 24 hours) will get individually tailored dietary advice, reinforced by weekly supportive phone/email support. If at 4 weeks, there has not been a desired increase in potassium intake, the patients will be prescribed an additional potassium supplement. Testing at 4 weeks will be conducted again to confirm the efficacy of the potassium supplement. Final measurements will be planned at 52 weeks to observe and measure the persistence of the effect of diet or additional supplement. Concurrent measurements of sodium intake, blood pressure, participant satisfaction, safety measures will also be done.

The results of the study would help determine the most effective method of increasing potassium intake, thus reducing blood pressure, need for blood pressure lowering medicines, at the same time potentially increasing participant satisfaction. The current guidelines recommend changes in diet (not supplement) to increase potassium intake, hence the two stage design will only add supplements if the most rigorous dietary advice does not work. The Investigators have received letters of support from the World Hypertension League and Hypertension Canada in support of the research design and for dissemination and implementation of the findings.


Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Diet or Additional Supplement to Increase Potassium Intake: An Adaptive Clinical Trial
Estimated Study Start Date : February 2019
Estimated Primary Completion Date : February 2022
Estimated Study Completion Date : February 2024


Arm Intervention/treatment
Experimental: Dietary Counselling
All enrolled patients will undergo a 1:1 counselling with a registered dietitian (with possible inclusion of family members, as appropriate). The dietitian will undertake an assessment of the comorbidities (e.g. diabetes), dietary intake, dietary habits (e.g. eating out, food preparation, socio-cultural aspects) and provide an individually tailored strategy to increase potassium in the diet. Secondly, on a weekly basis, the dietitian will contact the patient by telephone, or electronically (as preferred by the patient) to reinforce the advice and provide support/advice as necessary.
Behavioral: Dietary Counselling
Individually tailored strategy to increase potassium in the diet.

Active Comparator: Potassium Citrate Supplement
Patients who are not able to successfully increase their potassium intake at 4 weeks with dietary counselling will receive potassium citrate supplements. They will receive oral potassium supplementation in the form of 50 to 100 mmol of potassium citrate (as 5 - 10 tablets of 10 mmol each or 25 to 50 ml of the liquid solution).
Behavioral: Dietary Counselling
Individually tailored strategy to increase potassium in the diet.

Drug: Potassium Citrate
Dosing of 50 to 100 mmol of potassium citrate per day (as 5 - 10 tablets of 10 mmol each or 25 to 50 ml of the liquid solution).
Other Name: K-Citra




Primary Outcome Measures :
  1. Successful increase in potassium intake [ Time Frame: 4 weeks ]
    As estimated by 24 hour urine results at 4 weeks, achieving a urinary sodium > 90 mmol/day.


Secondary Outcome Measures :
  1. Persistence of increase in potassium intake at 52 weeks [ Time Frame: 52 weeks ]
    As estimated by comparison of persistence of change in potassium intake (as estimated by 24 hour urine results) from 4 weeks to 52 weeks.

  2. Hyperkalemia Events [ Time Frame: 4 weeks to 52 weeks ]
    Any episodes of hyperkalemia (as defined as a serum potassium greater than the 5.1 mmol/L)

  3. Gastrointestinal Events [ Time Frame: 4 weeks to 52 weeks ]
    Gastrointestinal side effects, specifically changes in bowel habits, belching and/or flatulence; abdominal pain or cramps.



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Provides signed and dated informed consent form
  2. Diagnosis of hypertension (either on treatment; or not on treatment with an ABPM with daytime SBP > 140 or DBP > 90) 3 Male or female, aged 18 and greater 4 24-Hour Urine K < 60 mmol/day

Exclusion Criteria:

  1. Serum Potassium < 3.3 or > 5.1 mmol/L
  2. GFR < 45 ml/min/1.73m2
  3. Primary hyperaldosteronism
  4. Pregnancy or lactation
  5. Psychiatric disorder which, in the opinion of the investigator, would interfere with the study, or inability to give consent
  6. Severe Liver disease
  7. Metabolic Alkalosis (HCO3 > 32 mmol/L)
  8. Exclude patients who need to be started on renin-angiotensin-aldosterone blockade in the first 3 months.
  9. Gastrointestinal disorder (eg delayed gastric emptying, dysphagia, oesophageal/gastric/duodenal ulcer)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03809884


Contacts
Contact: Jessica Wagner, BSc 613-738-8400 ext 81625 jewagner@toh.ca
Contact: Julie Leidecker 613-738-8400 ext 81623 jleidecker@toh.ca

Locations
Canada, Ontario
Ottawa Hospital Research Institute Not yet recruiting
Ottawa, Ontario, Canada, K1H7W9
Contact: Jessica Wagner    6137985555 ext 82514      
Principal Investigator: Swapnil Hiremath, MD PhD         
Sub-Investigator: Marcel Ruzicka, MD MPH         
Sponsors and Collaborators
Ottawa Hospital Research Institute
Investigators
Principal Investigator: Swapnil Hiremath, MD MPH The Ottawa Hospital

Responsible Party: Ottawa Hospital Research Institute
ClinicalTrials.gov Identifier: NCT03809884     History of Changes
Other Study ID Numbers: 20180873-01H
First Posted: January 18, 2019    Key Record Dates
Last Update Posted: January 18, 2019
Last Verified: January 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Ottawa Hospital Research Institute:
High blood pressure
Potassium
Potassium Citrate
Dietary Counselling
Hypertension

Additional relevant MeSH terms:
Hypertension
Vascular Diseases
Cardiovascular Diseases
Citric Acid
Potassium Citrate
Anticoagulants
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action
Diuretics
Natriuretic Agents
Physiological Effects of Drugs
Expectorants
Respiratory System Agents