Long-Term Effect of Salt Substitute on All-Cause and Cardiovascular Disease Mortality: An Exploratory Follow-Up of a Randomized Controlled Trial.

Hao Sun,Bo Zhou,Hailong Wang,Bing Ma,Xiaomei Wu

doi:10.3389/fcvm.2021.645902

Abstract

Background: Salt substitute, a strategy for salt reduction, has been shown to decrease blood pressure and the incidence of hypertension. However, whether its hypotensive effect will reduce long-term mortality remains unclear. Our study reported an exploratory follow-up of mortality outcomes from previous randomized controlled trial to assess the long-term effect of low-sodium salt on total and cardiovascular disease (CVD) mortality.Methods: Participants who completed a previous 3-year double-blind randomized controlled trial were followed up from 2009 to 2019 to collect mortality data. Multivariable Cox regression models were used to evaluate the association between low-sodium salt intervention and all-cause and CVD mortality.Results: Four hundred and forty participants completed the intervention trial, of which 428 participants had death outcome data recorded after 10 years follow-up: 209 in a salt substitute group and 219 in a normal salt group. Fifty participants died during follow-up, 25 died due to CVD. No significant differences in relative risks were found for all-cause mortality [HR = 0.81, 95% confidence interval (CI): 0.46–1.42] and CVD mortality (HR = 0.58, 95% CI: 0.26–1.32) in unadjusted analyses. After adjusted with age and alcohol drinking status, there were significant reductions for stroke mortality among all participants (HR = 0.26, 95% CI: 0.08–0.84) and for CVD mortality (HR = 0.38, 95% CI: 0.16–0.92) and stroke mortality (HR = 0.25, 95% CI: 0.08–0.82) among hypertensive participants.Conclusions: Compared to normal salt, salt substitute might reduce the risk of CVD death, especially stroke among hypertensive patients. Our exploratory follow-up results provide potential evidence that low-sodium salt may be an accessible and effective strategy for prevention of CVD events, but definitive randomized controlled trials are warranted.

Highlights

According to the Global Burden of Disease (GBD) report, cardiovascular disease (CVD) is the leading cause of death globally, accounting for 17.8 million deaths in 2017 [1]
The principal reasons for participants lost to follow-up were those who moved beyond observation and others reluctant to follow the prescribed schedule
As 6 participants died during intervention and 6 participants could not be traced, valid follow-up information relating to death outcomes was obtained from 428 participants only, 209 in the salt substitute group and 219 in normal salt group (Figure 1)

Summary

Introduction

According to the Global Burden of Disease (GBD) report, cardiovascular disease (CVD) is the leading cause of death globally, accounting for 17.8 million deaths in 2017 [1]. In China, due in part to traditional dietary habits, salt consumption has been shown to be the highest in the world, with adults consuming on average over 10 grams of salt daily (12.9 g/d in 1992, 12 g/d in 2002, and 10.5 g/d in 2015) [7]: over twice the WHO (World Health Organization) recommended limit (5 g/d) [8]. It is imperative to explore suitable strategies for salt reduction in China, without undue changes to dietary habits and culture. A strategy for salt reduction, has been shown to decrease blood pressure and the incidence of hypertension. Our study reported an exploratory follow-up of mortality outcomes from previous randomized controlled trial to assess the long-term effect of low-sodium salt on total and cardiovascular disease (CVD) mortality

Methods

Results

Discussion

Conclusion