Salt Restriction in the Treatment of Isolated Systolic and Combined Hypertension

Abstract

The most recent recommendations of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII) have emphasized dietary sodium (salt) restriction as a major lifestyle intervention with which to reduce blood pressure in those with “prehypertension” and as adjunctive therapy in combination with antihypertensive drugs in those with established hypertension.1 The benefit of a reduction in salt intake in lowering blood pressure in many, but not all hypertensive subjects, is well known and widely accepted on the basis of numerous trials.2 Nonetheless, debate continues regarding the extent of restriction required and whether all forms of hypertension benefit. He et al, in this issue of Hypertension , provide new insight into the impact of modest salt restriction on blood pressure in those with isolated systolic hypertension, as well as those with combined systolic–diastolic hypertension by reanalyzing data from 4 previous trials that they conducted.3 Among 24 subjects with isolated systolic hypertension and an average age of 63 years, a mean reduction of urinary sodium excretion from 175 to 87 mmol/d for 1 month resulted in an average decrease of 10/1 mm Hg (systolic/diastolic) (baseline 166/86; intervention 156/85) in blood pressure. These findings are similar to much larger drug intervention studies in such subjects demonstrating significant decreases in systolic pressure without appreciable changes in diastolic pressure. Among 88 younger (average age, 55 years) subjects with systolic/diastolic hypertension, a reduction from 175 to 98 mmol/d in average sodium excretion resulted in an …