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 patients classified as having low-renin hypertension, whereas increases were most common 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. Clinical Pharmacology and Therapeutics (1980) 27, 544–546; doi:10.1038/clpt.1980.76