Effect of salt substitute and antihypertensive medications among high cardiovascular risk patients: A sub-study of Salt Substitute and Stroke Study (SSaSS)

The relationship between the differential protective effect of salt substitute between hypertensive and normotensive individuals and the use of cardiovascular medications remains unclear. This study involved 4211 individuals with a history of stroke or hypertension who participated in the Salt Substitute and Stroke Study (SSaSS) from 120 villages in Shanxi Province. The aim of this study was to investigate the differences in major adverse cardiovascular events and blood pressure changes between the salt substitute and the regular salt group in the subgroups of participants taking different antihypertensive medications. Mixed models were employed and adjusted for the cluster effect (village) and potential confounding variables. During the average follow-up period of 4.66 years, a significantly protective effect of salt substitute on reducing the risk of cardiovascular events was observed in the participants who taking antihypertensive medications (rate ratio: 0.81, 95% CI: 0.68 to 0.95. p = 0.011), whereas no significant effect in participants not taking antihypertensive medications (rate ratio: 0.91, 95% CI: 0.62 to 1.32, p = 0.612). Significant effects to lower systolic blood pressure of the salt substitutes were observed in the participants who took different antihypertensive medications. This study emphasized that the use of salt substitutes might enhance the efficacy of anti-hypertensive medications in lowering blood pressure and reducing the risk of adverse cardiovascular events.