AzTrials
AzTrials

Blood PressureNCT03909659

The Effects on Blood Pressure of Salt Substitute Among Adults With Hypertension in India

A study testing Dietary sodium reduction in people with Blood Pressure, run by The George Institute at 1 site in India.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Blood pressure is a key modifiable risk factor for cardiovascular disease in India. Drug therapies are highly effective and are recommended by local guidelines to reduce the risks of serious cardiovascular complications. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Blood Pressure
What is being tested?
Dietary sodium reduction
Could I receive a placebo?
No, everyone receives an active treatment
How many people
502 participants
Where
1 siteIndia
Study dates
25 Nov 2019to 30 Nov 2020
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Male or female aged 18 years or over
  • History of hypertension diagnosed by a health professional - hypertension may be self-reported and antihypertensive drugs may or may not be used for management. There is no entry criterion based upon blood pressure measurements made at the baseline survey
  • Eat most of their meals in the home
  • Consent to participate

Who cannot join

  • Participant or family member is using a potassium-sparing diuretic
  • Participant or family member is using a potassium supplement
  • Participant or family member has known significant renal dysfunction
  • Participant or family member has other reason for concern about use of salt substitute
  • Participant is not expected to live longer than 6 months from the date of assessment
  • Another member of the household is already enrolled in the study

Trial locations and contacts

1 site in 1 country.

India1 site
  • The George Institute for Glaobal Health India

    New Delhi, 110025

Other trials in India

About this study

Official title: A Randomized-Controlled Trial to Determine the Effects on Blood Pressure of A Reduced-sodium Added-potassium Salt Substitute Among Adults With Hypertension in India

Blood pressure is a key modifiable risk factor for cardiovascular disease in India. Drug therapies are highly effective and are recommended by local guidelines to reduce the risks of serious cardiovascular complications. Behavioural approaches to blood pressure control based upon sodium reduction are also recommended but there are no interventions proven effective in India.

Mean sodium intake in India is about 5g/day (equivalent to about 12.5g salt) which is, more than double World Health Organization (WHO) recommendations. Reduced sodium, added potassium salt substitutes have favourable effects on blood pressure in settings where discretionary salt use is high, but have not been tested in India. This single-site, Salt Substitute on blood pressure in India Study will investigate the effects of reduced sodium added potassium salt substitution on blood pressure in rural areas where hypertension is a prevalent disease problem and additional, scalable and affordable interventions are required. The primary objective is to assess the effects of salt substitute on SBP at 3 months follow-up. The secondary objectives are to determine effects on DBP, urinary sodium and potassium levels and to determine acceptability of the salt substitute.

The study will be a double-blinded, randomized-controlled trial done in the Hyderabad region amongst adult volunteers with a history of hypertension diagnosed by a health professional. The main exclusion criteria will be known serous kidney disease or use of potassium containing medications by the individual or others living in the household. Written informed consent will be obtained from potential participants followed by baseline data collection. Eligible individuals will then be assigned at random to receive double-blind salt or salt substitute which will be used to replace all dietary salt used for cooking and seasoning over the next 3 months. Follow-up will be at one and three months after randomisation for blood pressure, urinary electrolytes and acceptability of the intervention.

Read the detailed description

Excess sodium intake is associated with high blood pressure which is a leading risk for cardiovascular disease (CVD) in India. Drug therapies are highly effective interventions for blood pressure lowering and are recommended by local guidelines to reduce the risks of serious cardiovascular complications. Behavioural approaches to blood pressure control based upon sodium reduction are also recommended but there are no interventions proven effective and sustainable in India.

Mean sodium intake in India is about 5g/day (equivalent to about 12.5g salt) which is more than double World Health Organization (WHO) recommendations. Reduced sodium, added potassium salt substitutes have favourable effects on blood pressure in settings where discretionary salt use is high, but have not been tested in India. Salt substitution is of particular interest because it has great potential for scaling in under-served and resource poor settings.

This study will investigate the effects of salt substitution on blood pressure in rural areas where hypertension is a highly prevalent disease problem and additional, scalable and affordable blood pressure lowering interventions are required. Accordingly, the primary objective is to assess the effects of a reduced sodium, added potassium salt substitute compared to usual salt on systolic blood pressure (SBP) at 3-months follow-up. The secondary objectives are to determine effects on diastolic blood pressure (DBP), urinary sodium and potassium levels and to determine acceptability of the salt substitute among patients with hypertension.

The study will be a double-blinded, randomized-controlled trial done in the villages of the Hyderabad district amongst adult volunteers with a self-reported history of hypertension. The main exclusion criteria will be known serous kidney disease or use of potassium containing medications by the individual or others living in the household. Written informed consent will be obtained from potential participants followed by baseline data collection. Eligible individuals will then be assigned at random to receive double-blind salt or salt substitute which will be used to replace all dietary salt required for cooking and seasoning in the household over the next 3-months. Follow-up will be at one and three months after randomisation for assessment of blood pressure and acceptability of the intervention, with urinary electrolytes measured at baseline and 3-months.

The sample size will be 440 participants randomized in a 1:1 ratio to intervention or control which will provide more than 80% power (P=0.05) to detect a 5 mmHg or greater difference in SBP between randomized groups. This estimate assumes a mean of 140mmHg and a standard deviation of 20mmHg for SBP at baseline. We will seek to recruit comparable numbers of men and women. Analyses will be done using the principle of intention-to-treat and a repeated measures analysis of variance that incorporates baseline, 1-month and 3-month measures of SBP to maximize the efficiency of the analysis.

Conditions
Blood Pressure
Being tested
Dietary sodium reduction

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Dietary sodium reductionBehavioural

    A supply of a reduced-sodium added-potassium salt substitute

Study groups in NCT03909659
Study groupRoleWhat they receive
ControlNo interventionNormal salt
Reduced-sodium added-potassium salt substituteExperimentalsalt substitute
Receives: Behavioral: Dietary sodium reduction

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Systolic Blood Pressure

    As measured by using an automated blood pressure monitor according to established standardized methods.

    Measured: three months

Secondary outcomes (4)
  1. Diastolic Blood Pressure

    As measured by using an automated blood pressure monitor according to established standardized methods.

    Measured: three months

  2. Urinary sodium excretion

    A field-based measurement of sodium made using the meter (HORIBA Ltd, Japan), which uses a direct ion-selective electrode technique to measure sodium concentrations.

    Measured: three months

  3. Urinary potassium excretion

    A field-based measurement of potassium made using the meter (HORIBA Ltd, Japan), which uses a direct ion-selective electrode technique to measure potassium concentrations.

    Measured: three months

  4. Acceptability of the study salt substitute

    Acceptability of the study salt substitute will be measured using the following questions at baseline and follow-up: How many days in the last week did you use study salt? If you were meant to use the study salt in the last week but did not use it every day, what is the reason? If you use the study salt in the last week: How did you use it? How many meals did you use the study salt during the day? Did you enjoy the taste? (1 = disliked a lot; 10 = liked a lot)

    Measured: three months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Apr 2019
  2. Study start25 Nov 2019
  3. Primary completion30 May 2020
  4. Study completion30 Nov 2020

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
502 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03909659
Sponsor's protocol ID
SSiIS
Status last verified
Mar 2021
First submitted
31 Mar 2019
Last updated
1 Apr 2021
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Yu J, Thout SR, Li Q, Tian M, Marklund M, Arnott C, Huffman MD, Praveen D, Johnson C, Huang L, Pettigrew S, Neal B, Wu JHY. Effects of a reduced-sodium added-potassium salt substitute on blood pressure in rural Indian hypertensive patients: a randomized, double-blind, controlled trial. Am J Clin Nutr. 2021 Jul 1;114(1):185-193. doi: 10.1093/ajcn/nqab054.

    PubMed 33782684

Questions about this trial

What is this clinical trial studying?

A study testing Dietary sodium reduction in people with Blood Pressure, run by The George Institute at 1 site in India.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 1 Apr 2021. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in India. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Systolic Blood Pressure (time frame: three months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03909659, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Apr 2021.

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