Launching a salt substitute to reduce blood pressure at the population level in Peru

Background

This project aimed to implement, using a stepped wedge trial design, a population-level intervention to replace high-sodium salt for a salt substitute (low-sodium, high-potassium salt) to reduce blood pressure levels among adults aged 18 years and over in Tumbes. Tumbes, is a department located in the north coastal region of Peru on the border with Ecuador. It is a semi-urban area consisting of more than 100 villages of varying size with an approximate total population of 80,000 people. It is comprised of a large “mestizo” population (people of mixed European and Amerindian ancestry) where the traditional agricultural and fishing landscape has become intermixed with rapidly growing urban sections. The implementation of this strategy involved a range of participants, from villagers, their families and local leaders to local institutions as well as local, regional and national authorities.

Aims

To implement and assess the impact of an intervention using a salt substitute on blood pressure at the population level using a stepped wedge trial design.

Project plan

Study participants: The team included villages with 100 to 200 inhabited households. According to the most updated census available at the time (2010), there were 20 villages with this number of households (and potentially almost 10,000 villagers who might receive the intervention). Participants from 6 randomly-selected villages were involved in this stepped wedge randomized trial to use a salt substitute to reduce blood pressure at the population level.

Phase 1

To assess predisposition patterns towards incorporating the new salt substitute into daily cooking among villagers, authorities and other potential stakeholders, in order to inform and construct the structure of the intervention in the local communities and ensure successful implementation. The team used focus groups and in-depth interviews techniques.

Phase 2

To implement and assess the impact of an intervention using a salt substitute on blood pressure at the population level using a stepped wedge trial design.

Impact

The project showed that a population wide intervention to use a salt substitute in Tumbes (Peru) led to a decrease in blood pressure; the impacts of the salt substitute were greater in people with existing hypertension. As well as lowering blood pressure levels, the risk of developing high blood pressure was halved in people who used the salt substitute. Evidence from this project was presented in a TED talk.

Publications and output

GACD have published an end-of-programme report providing a comprehensive summary of the programme and outcomes.