Effect of salt substitute and medication use among high cardiovascular risk patients

Abstract

Introduction: Previous studies have shown that the protective effect of salt substitute varied between the hypertensive population and the normotensive population, but it was not clear whether it was related to cardiovascular drugs. The purpose of this study is to explore the effect of salt substitutes and anti-hypertensive drugs on blood pressure and adverse cardiovascular events. Methods: 4211 people with a history of stroke or hypertension from 120 villages in Shanxi Province who participated in an open-label cluster randomized controlled trial (SSaSS) were included in this study. Generalized linear mixed models and linear mixed models were used to explore the effect of salt substitute on blood pressure and adverse cardiovascular events in different group of population respectively, adjusting for the stratification variables at randomization (village) as well as potential confounding variables. Results: Salt substitute reduced the risk of adverse cardiovascular events in participants who took anti-hypertensive drugs(28.63 events vs. 35.96 events per 1000 person-years; rate ratio, 0.75, 95% CI, 0.59 to 0.95; P=0.016) while no significant effect among the participants who did not take any anti-hypertensive drugs. Salt substitute reduced the blood pressure in participants who took anti-hypertensive drugs with a mean SBP difference of -4.38mmHg (95% CI: -6.08 to -2.67, P<0.001) and a mean DBP difference of -1.31mmHg (95% CI: -2.42 to -0.21, P=0.020), while no significant blood pressure difference among the participants who did not take any anti-hypertensive drugs. Conclusions: Combining salt substitute with anti-hypertensive drugs could reduce blood pressure and the risk of cardiovascular events.