Divergent blood pressure responses during short-term sodium restriction in hypertension.

In untreated patients with essential hypertension, daily sodium intake was reduced from 197 to 70 mEq/day in 82 outpatients and from 124 to 14 mEq/day in 25 patients in a metabolic ward. During the 10 days of sodium restriction 17% of the outpatients and 40% of the inpatients had mean blood pressure decreases of at least 10 mm Hg, but in 17% of the outpatients and 28% of the inpatients mean pressure rose at least 5 mm Hg. Most blood pressure decreases occurred in the group with high-renin hypertension. Our short-term experience suggests that dietary salt deprivation may not be effective treatment for all patients with hypertension and may even be counterproductive in some.