Sodium and potassium intake in the management of high blood pressure

Abstract

Reduction of sodium intake lowers blood pressure in many patients with essential hypertension. The fall in blood pressure with salt restriction is related to the severity of blood pressure before treatment, and this may explain why there is continuing controversy about the role of sodium restriction in patients with mild or borderline hypertension. The mechanism whereby salt restriction lowers blood pressure appears to be dependent on a relative lack of rise in renin and, thereby, angiotensin II with the salt restriction. Moderate reduction of sodium intake is additive to the effect of blood-pressure-lowering drugs, particularly those that block the renin-angiotensin system such as beta-blockers and converting enzyme inhibitors. Increasing potassium chloride intake has also been shown to cause a fall in blood pressure in patients with essential hypertension when on their normal sodium intake. However, more recent work shows that when patients are already restricting salt intake, potassium chloride supplementation has little or no effect on blood pressure.