Preventing the Rise in Blood Pressure With Age Using Reduced-sodium Salt

Study Overview
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Brief Summary
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The study is a small-scale, short-term unblinded feasibility study to explore the acceptability and feasibility of implementing a reduced-sodium iodised salt intervention in Nigeria. This study will be used to inform a large-scale intervention trial comparing the effects of reduced-sodium salt versus regular salt on the rise in blood pressure with age.

Detailed Description
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Reduced-sodium salts are a proven method for reducing sodium intake and lowering blood pressure. No studies to date have tested the effects of sodium reduction on the rise in blood pressure with age during adulthood or the critical periods of childhood and adolescence. The investigators want to explore whether reducing dietary sodium intake using reduced-sodium salt in comparison to regular salt, will attenuate the rise in blood pressure with age. This feasibility study aims to determine the feasibility of implementing a reduced-sodium iodised salt (66% potassium chloride, 34% sodium chloride) intervention in Nigeria. Specifically, the investigators will explore the feasibility of recruiting households with at least one child or adolescent 6-17 years of age and one adult ≥18 years, the acceptability of the reduced-sodium salt intervention, adherence to study procedures and data collection methods, and the effect of the reduced-sodium salt intervention on blood pressure. Secondary outcomes include household eligibility, household composition, willingness to engage in monthly follow-up visits in a longer-term trial, blood pressure, urinary sodium and potassium concentrations, height and weight. This study will be used to inform a large-scale intervention trial comparing the effects of reduced-sodium salt versus regular salt on the rise in blood pressure with age. The study will be conducted in two rural communities in Nigeria and will recruit 30 households (approximately 150 participants). All participants will be provided with the reduced-sodium salt intervention to replace all regular salt used for cooking, seasoning and food preservation over a 2-month period; there will be no control. Follow-up visits will be at 1 month and 2 months after the baseline visit, conducted either at the home or a local community healthcare centre.

Official Title
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A Non-randomised Feasibility Study for a Large-scale Clinical Trial (Phase II) Testing Reduced-sodium Salt for the Prevention of the Rise in Blood Pressure With Age Among Children and Adults (6+ Years) in Nigeria (RAISED)

Conditions
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Blood Pressure

Intervention / Treatment
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* Behavioral: Reduced-sodium potassium-enriched salt


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least one household member is a child or adolescent (6-17 years) and at least one household member is an adult (≥18 years) All household members consume greater than half of meals as food prepared in the home (self-report) All household members provide signed informed consent/assent (consent obtained from legal guardians for those <18 years of age; assent also obtained from children/adolescents ≥12 years of age) Exclusion Criteria: Any household member has serious renal impairment. Any household member uses a potassium-sparing diuretic. Any household member uses a potassium supplement. Any household member has other reason for concern about the use of reduced-sodium salt.

Ages Eligible for Study
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Minimum Age: 6 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Reduced-sodium potassium-enriched salt<br>Reduced-sodium potassium-enriched salt | Behavioral: Reduced-sodium potassium-enriched salt<br>* Supply and use of a reduced-sodium, potassium-enriched iodised salt (66% potassium chloride, 34% sodium chloride).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of recruitment | Measured as the number of households recruited each month | 2 months | 
| Adherence to the reduced-sodium salt intervention | Measured as the self-reported proportion of regular salt replaced with intervention salt at each follow-up visit. The investigators will also estimate the quantity of intervention salt used by the household at each follow-up visit by visually estimating the amount of intervention salt that remains unused. | 2 months | 
| Acceptability of the reduced-sodium salt intervention | Measured as the percentage of participants that identify 'good', 'really good' or 'super good' on a brief questionnaire administered at the 2-month follow-up visit | 2 months | 
| Completion rate of visits | Measured as the percentage of participants that provide key data points (e.g., blood pressure, safety) at each visit | 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total number and percentage of households eligible to participate in the study | Measured as the number of eligible households over the number of households approached at registration visits. | 2 months | 
| Average number of participants per household and breakdown by age group |  | 2 months | 
| Willingness to engage in monthly follow-up visits in a longer-term trial (48-months) | Measured as the percentage of participants that identify as 'willing', 'very willing' or 'super willing' on a brief questionnaire administered at the 2-month follow-up visit | 2 months | 
| Systolic and diastolic blood pressure | Measured using validated and automated sphygmomanometers, according to standard practices and definitions outlined in the Global Alliance for Chronic Disease (GACD) data dictionary | 2 months | 
| Urinary sodium concentration | Measured as the mmol/L of sodium from a spot urine sample | 2 months | 
| Urinary potassium concentration | Measured as the mmol/L of potassium from a spot urine sample | 2 months | 
| Weight |  | 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Reduced-sodium salt, Potassium-enriched salt, Salt reduction, Blood pressure, Salt, Feasibility