Effect of salt substitution on community-wide blood pressure and hypertension incidence

Abstract

reduction in salt intake has been identified as one of the most cost-effective measures for improving health outcomes 1-3. Different studies have reported the benefit of salt-reduction interventions in decreasing blood pressure and cardiovascular events 4-6. Results from a meta-analysis show that modest reductions in salt intake are followed by a decrease in blood pressure levels among both hypertensive and normotensive subjects 7. Nevertheless, the evidence of the effectiveness of population-level, behavior change interventions on reducing salt intake is inconsistent, suggesting that education and awareness-raising interventions alone are not sufficient for reducing population salt intake 8. Salt substitutes, that is, salt enriched with potassium or other similar components such as magnesium or aluminum, have been reported to be effective in reducing both systolic blood pressure (SBP) and diastolic blood pressure (DBP) 9-11. Under controlled conditions, salt-substitution strategies can reduce the SBP up to 5 mm Hg and the DBP up to 1.5 mm Hg, and this effect was larger among individuals with hypertension than among normotensive subjects 12. There is limited evidence, however, from studying the population-level effect of these salt-substitution interventions. A cluster randomized trial conducted in China, evaluating the effect of a community-based sodium reduction program using a salt substitute on salt consumption and blood pressure, found reductions in urinary sodium excretion but not in blood pressure 13. Currently, an increasing number of countries have adopted national salt-reduction strategies 14. Salt-substitution initiatives could aid such strategies in settings where added salt during cooking is the main source of salt intake, particularly in low-and middle-income countries where hypertension rates are increasing at a fast rate 15. The aim of the present study was to assess the efficacy of a pragmatic intervention using a salt-substitution strategy to reduce blood pressure, as well as its impact on the incidence of hypertension, at the population level, using a stepped-wedge cluster trial in Peru. Results Population characteristics. Figure 1 shows the details of participants' enrollment, including dates, number of subjects assessed, those lost to follow-up and those analyzed for each step of the trial. A total of 2,376 (91.2%) out of 2,605 eligible subjects in the 6 villages were enrolled in the study from 2 April to 17 July, 2014: 49.6% females, mean age 43.3 ± 17.2 years. Of note, only 18.9% of the individuals had ≥12 years of education, 68.1% were in the overweight or obesity range with a body mass index (BMI) ≥25 kg m −2 and 18.3% had a diagnosis of hypertension. Table 1 shows the characteristics of the study population at baseline and a comparison between the control and the intervention periods. There were differences among villages in the distribution of age, education, wealth index, BMI, SBP, DBP and hypertension (see Supplementary Table 1). Effect of the salt substitute on blood pressure levels....

The slowdown in the reduction rate of premature mortality from cardiovascular diseases puts the Americas at risk of achieving SDG 3.4: A population trend analysis of 37 countries from 1990 to 2017

“…Although to contain and reverse the recently observed slowdown and stagnation of CVD burden must be the highest priority for the entire Region, the challenge is even greater for the LMIC because they do not have enough resources neither the health system prepared to resist this enormous burden. This challenge requires a more innovative, socially inclusive, and strategic effort to implement evidence‐based low‐cost interventions with potential to safe millions of deaths, such as salt reduction through the replacement of regular salt with potassium‐enriched substitutes which can reduce blood pressure and hypertension incidence, 38 elimination of artificial trans‐fat, and improvement of hypertension management in primary care through simple standardized treatment protocols, a core set of medications, team‐based care and closely monitor patient progress and system performance 39 . Along with theses key interventions, this Region and particularly its most vulnerable economies can benefit significantly with more aggressive measures to reduce tobacco use and to overturn the obesity epidemic.…”

Electrolytes and Cardiovascular Disease Risk

“…15 In a recently published randomized intervention in Peru, use of a 25% potassium salt substitute corresponded with reductions in SBP of 1.29 mm Hg (P = .04) in a population sample and by 1.92 mm Hg (P = .006) in a subgroup of participants with hypertension. 25 Decreasing incidence of CVD (13.1 per 1000 persons vs 20.5 per 1000 persons) have also been reported in a randomized intervention of adult males receiving a 50% potassium salt substitution. 24 However, the authors noted only modest reductions in sodium intake within this experimental group.…”

Salt substitution to lower population blood pressure

“…Each village crossed over from the control condition (no salt substitution) to the intervention (community-wide salt substitution) sequentially, in an order determined by randomization, and remained in the intervention condition until the end of the study, so that salt substitution was implemented in all villages (known as a 'stepped-wedge' design). The results showed that salt substitution caused a reduction in BP by 1.23 (0.38-2.07) mmHg/0.72 (0.10-1.34) mmHg (systolic/diastolic) in all participants, and in those with normal BP, hypertension incidence was halved 4 . These findings provide further support for the use of salt substitutes as a population-level strategy to prevent hypertension.…”

“…A recent meta-analysis of 13 randomized trials showed that replacing the usual salt with low-sodium, high-potassium salt substitutes reduced BP to a degree of clinical and public-health importance 3 . A study by Bernabe-Ortiz et al, published in this issue of Nature Medicine, is the latest addition to efforts in extending the use of salt substitutes from clinical-trial settings to the population level 4 . The authors used a stepped-wedge cluster randomized trial design in six villages in northern Peru to replace the usual salt with a salt substitute and found that salt substitution will most likely have health benefits.…”