Pan African Clinical Trials Registry
South African Medical Research Council, South African Cochrane Centre
PO Box 19070, Tygerberg, 7505, South Africa
Telephone: +27 21 938 0506 / +27 21 938 0834 Fax: +27 21 938 0836
Email: pactradmin@mrc.ac.za Website: pactr.samrc.ac.za
Trial no.: PACTR202306727520808 Date of Approval: 19/06/2023
Trial Status: Registered in accordance with WHO and ICMJE standards
TRIAL DESCRIPTION
Public title Sodium in Adolescents and adults Lowering Trial: the SALT trial
Official scientific title A randomised controlled trial to assess the efficacy of a low sodium salt substitute enriched with potassium to improve sodium-to-potassium ratio and reduce blood pressure in adolescents and their families in Soweto, South Africa
Brief summary describing the background and objectives of the trial The burden of non-communicable disease in Sub-Saharan Africa has increased in recent years and high blood pressure (BP) is the leading cause. In Africa, BP levels have risen steadily, and are now among the highest in the world. Diet contributes significantly to raised BP with dietary sodium intake being an established risk factor for hypertension development and cardiovascular disease (CVD). Dietary potassium, on the other hand, has been shown to have a protective effect on BP, potentially through its role in counteracting the negative effects of sodium on BP. A recent randomised trial found that providing participants, with a history of stroke or aged >60 years and with high BP, with a potassium-enriched low sodium salt substitute (potassium chloride; KCl) reduced rates of stroke, major cardiovascular events, and deaths compared to those using traditional salt (sodium chloride; NaCl) over five years. With high population salt intake and typically low potassium intake, the use of salt substitutes with reduced sodium and increased potassium levels within the household may present a feasible method to reduce BP across generations. Despite growing evidence of the impact of salt substitutes on BP in other populations, there is currently limited data for African populations, known to be more salt-sensitive. This study aims to assess in African families, the effectiveness of a potassium-enriched low sodium salt substitute compared to usual salt in improving urinary sodium-to-potassium ratio and lowering blood pressure over four months. This study will employ a two-arm double-blind controlled trial (1:1), randomising individuals to the blinded intervention or control to evaluate in adolescents and adults: Difference in change in spot urinary sodium-to-potassium molar ratio from baseline to 16 weeks and in adults: Difference in change in systolic BP from baseline to 16 weeks.
Type of trial RCT
Acronym (If the trial has an acronym then please provide) The SALT trial
Disease(s) or condition(s) being studied Circulatory System,Nutritional, Metabolic, Endocrine
Sub-Disease(s) or condition(s) being studied
Purpose of the trial Prevention
Anticipated trial start date 10/07/2023
Actual trial start date 19/02/2024
Anticipated date of last follow up 10/06/2024
Actual Last follow-up date
Anticipated target sample size (number of participants) 1500
Actual target sample size (number of participants)
Recruitment status Recruiting
Publication URL
Secondary Ids Issuing authority/Trial register
STUDY DESIGN
Intervention assignment Allocation to intervention If randomised, describe how the allocation sequence was generated Describe how the allocation sequence/code was concealed from the person allocating the participants to the intervention arms Masking If masking / blinding was used
Parallel: different groups receive different interventions at same time during study Randomised Simple randomization using a randomization table created by a computer software program Sealed opaque envelopes Masking/blinding used Care giver/Provider,Outcome Assessors,Participants
INTERVENTIONS
Intervention type Intervention name Dose Duration Intervention description Group size Nature of control
Experimental Group Potassium enriched low sodium salt substitute 16 weeks 50% Potassium Chloride (KCl) 50% Sodium Chloride Blend (NaCl) Salt 750
Control Group Usual table salt 16 weeks 100% Sodium Chloride (NaCl) Salt 750 Placebo
ELIGIBILITY CRITERIA
List inclusion criteria List exclusion criteria Age Category Minimum age Maximum age Gender
1. Male/Female. 2. African descent living in Soweto. 3. Adolescents, aged 13-19 years, primary caregiver (parent/guardian) and where the primary caregiver is <40 years of age, also a member of the household (aged 40-70 years). 4. Eats in the home a minimum of five days a week. 5. Stays in the home a minimum of five days a week. 6. Individuals presenting with new clinical hypertension (will be referred). 7. Use of ACE inhibitors or Angiotensin receptor blockers (participant will be flagged for monitoring. 1. Inability to read or understand English. 2. Self-reported previous diagnosis of kidney disease/diminished kidney function (any household member regardless of participation). 3. Urine dipstick indicating potential kidney disease/diminished kidney function as indicated by proteinurea (any household member regardless of participation). 4. Estimated Glomerular Filtration Rate below 60 mL/min (any household member over 20 years of age regardless of participation). 5. Use of Potassium-sparing diuretics (any household member regardless of participation). 6. Potential contraindication to the potassium-enriched salt (any household member regardless of participation). 7. Considered to eat most meals outside of the home. 8. Previous diagnosis or currently self-reporting any eating disorder. 9. Participating in any other trial. 10. Households without cooking facilities. 11. High-level athletes. 12. Self-reported pregnancy at time of screening (any household member regardless of participation). Adolescent: 13 Year-18 Year,Adult: 19 Year-44 Year,Aged: 65+ Year(s),Middle Aged: 45 Year(s)-64 Year(s) 13 Year(s) 100 Year(s) Both
ETHICS APPROVAL
Has the study received appropriate ethics committee approval Date the study will be submitted for approval Date of approval Name of the ethics committee
Yes 24/04/2023 Human Research Ethics Committee Medical University of the Witwatersrand
Ethics Committee Address
Street address City Postal code Country
Cnr York Road and 29 Princess of Wales Terrace, Parktown Johannesburg 2193 South Africa
OUTCOMES
Type of outcome Outcome Timepoint(s) at which outcome measured
Primary Outcome In adolescents and adults: Difference in change in spot urinary sodium-to-potassium molar ratio from baseline to 16 weeks. 16 weeks
Primary Outcome In adults: Difference in change in systolic BP from baseline to 16 weeks. 16 weeks
Secondary Outcome In adolescents: Difference in change in systolic and diastolic BP from baseline to 16 weeks. 16 weeks
Secondary Outcome In adults: Difference in change in diastolic BP and spot urinary sodium-to-potassium molar ratio from baseline to 16 weeks. 16 weeks
RECRUITMENT CENTRES
Name of recruitment centre Street address City Postal code Country
MRCWits Developmental Pathways for Health Research Unit 26 Chris Hani Road, Chris Hani Baragwanath Academic Hospital, College and Clinic Road Soweto 1864 South Africa
Wits Health Hubb 02229 Isikwama St, Jabulani Soweto 1868 South Africa
FUNDING SOURCES
Name of source Street address City Postal code Country
The University of New South Wales Level 3, Samuels Building, Gate 11, Botany Street, UNSW Kensington campus Sydney Australia
SPONSORS
Sponsor level Name Street address City Postal code Country Nature of sponsor
Primary Sponsor MRC Wits Developmental Pathways for Health Research Unit 26 Chris Hani Road, Chris Hani Baragwanath Academic Hospital, College and Clinic Road Soweto South Africa University
Secondary Sponsor Wits Health Hubb 02229 Isikwama St, Jabulani Soweto 1868 South Africa University
COLLABORATORS
Name Street address City Postal code Country
The University of New South Wales Level 3, Samuels Building, Gate 11, Botany Street, UNSW Kensington campus Sydney Australia
CONTACT PEOPLE
Role Name Email Phone Street address
Principal Investigator Aletta Schutte a.schutte@unsw.edu.au +61450315918 School of Population Health Samuels Building, Level 2, Room 223 Kensington Campus UNSW
City Postal code Country Position/Affiliation
Sydney Australia Professor and Principal Theme Lead
Role Name Email Phone Street address
Public Enquiries Simone Crouch simone.crouch@wits.ac.za +27729950919 26 Chris Hani Road, Chris Hani BaragwanathAcademic Hospital, College and Clinic Road
City Postal code Country Position/Affiliation
Soweto South Africa Post Doctoral Fellow
Role Name Email Phone Street address
Scientific Enquiries Aletta Schutte a.schutte@unsw.edu.au +61450315918 School of Population Health Samuels Building, Level 2, Room 223 Kensington Campus UNSW
City Postal code Country Position/Affiliation
Sydney Australia Professor and Principal Theme Lead
REPORTING
Share IPD Description Additional Document Types Sharing Time Frame Key Access Criteria
Yes Data obtained through this study may be provided to qualified researchers with academic interest in potassium-enriched salt substitutes. Data or samples shared will be coded, with no protected health information included. Approval of the request and execution of all applicable agreements (i.e. a material transfer agreement) are prerequisites to the sharing of data with the requesting party. Study Protocol Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis. Access to trial IPD can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a Data Sharing Agreement (DSA). For more information or to submit a request, please contact a.schutte@unsw.edu.au or shane.norris@wits.ac.za
URL Results Available Results Summary Result Posting Date First Journal Publication Date
No
Result Upload 1: Result Upload 2: Result Upload 3: Result Upload 4: Result Upload 5:
Result URL Hyperlinks Link To Protocol
Result URL Hyperlinks
Changes to trial information