Potassium Supplementation to Reduce Blood Pressure

Oxford Brookes University

Status: Completed

Conditions: Prehypertension

Treatments: Dietary Supplement: High potassium water; Dietary Supplement: Control low potassium water

Study type: Interventional

Funder types: Other

Identifiers

NCT05412654

221579

Details and patient eligibility

About

The aim of this study is to conduct a definitive trial to assess the efficacy of consuming 1L/day of water rich in potassium to reduce blood pressure in mild to moderately hypertensive adults. The objective is to assess the potential effect of the intervention on reducing systolic blood pressure. This study will comprise of a 4 week, double-blind, parallel randomised controlled trial. Participants will be adults with systolic blood pressure measurements of 130mmHg or greater. The intervention comprises advice to consume bottled water rich in potassium. The comparator will be regular bottled mineral water.This study will recruit 40 people with elevated systolic blood pressure (≥130mmHg) who are not regularly taking antihypertensive medication.

Enrollment: 40 patients

Sex: All

Ages: 20 to 64 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Willing and able to provide informed consent
• Between 20 to 64 years old
• English speaking
• Adults who are not receiving antihypertensive pharmacological treatment
• Recent (within 6 months) and latest systolic blood pressure measurement ≥130mmHg and/or diastolic ≥85 mmHg
• Have access to internet and equipment for video calling
• Able to post samples and equipment to OxBCNH
• Physically able to take own body measurements and blood pressure

Exclusion criteria

• Participation in another research study
• Unable to read and understand the instructions provided in English
• Unable to comply with experimental procedures or not follow testing safety guidelines
• People with cardiovascular conditions: heart attack or stroke within the last 3 months, heart failure of grade II New York Heart Association and more severe, or prolonged QT syndrome, angina, arrhythmia or atrial fibrillation.
• Uncontrolled type 2 diabetes (HbA1c> 9%)
• Type 2 diabetes controlled using exogenous insulin
• Previous or current diagnosis of diabetes complications such as nephropathy, retinopathy and neuropathy.
• People with type 1 diabetes
• Currently on any medication that may lead to hyperkalemia or fluid retention
• Currently being assessed for diagnosis of hypertension (not receiving treatment for high blood pressure)
• Already on clinician/HCP supervised diet or restricted diet
• They are planning on going away from home (holiday or other) during the 4 week intervention period and will not be able to take water during this time.
• Currently prescribed antihypertensive medications, or have been in the last 6 weeks
• Chronic kidney disease stage 1 (G1A2 or G1A3), 2 (G2A2 or G2A3), 3a, 3b, 4 or 5 based on UKKA (we will ask whether participants have been diagnosed with kidney disease by a clinician based on this criteria)
• They are planning to go on a diet or begin taking supplements containing potassium during the intervention
• Pregnant women (including women suspected of being pregnant) and breast-feeding woman.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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40 participants in 2 patient groups, including a placebo group

High potassium water

Experimental group

Description:

All participants will be provided with bottled water for the duration of the 4 week intervention to consume 1L/day. The intervention group will receive high potassium water. Participants will be instructed to consume 1 bottle (500 mL) within 2 hours after waking up and 1 bottle (500 mL) within 2 hours before going to bed (total 1L/day). Participants will continue with the same diet and exercise patterns in their daily life similar to before participating in the study, for the whole length of the intervention.

Treatment:

Dietary Supplement: High potassium water

Low potassium control water

Placebo Comparator group

Description:

All participants will be provided with bottled water for the duration of the 4 week intervention to consume 1L/day. The control group will receive regular bottled mineral water. Participants will be instructed to consume 1 bottle (500 mL) within 2 hours after waking up and 1 bottle (500 mL) within 2 hours before going to bed (total 1L/day). Participants will continue with the same diet and exercise patterns in their daily life similar to before participating in the study, for the whole length of the intervention.

Treatment:

Dietary Supplement: Control low potassium water