Salt Restriction For Resistant Hypertension

"Resistant hypertension" is the name doctors give to high blood pressure that turns out to be very difficult to treat effectively. Specifically, resistant hypertension is said to be present if your blood pressure is still not adequately controlled despite taking at least three medications for hypertension. Resistant hypertension affects more than 20% of all patients with high blood pressure.

A small study published this week in the journal Hypertension suggests that in people with resistant hypertension, significant restriction of dietary salt can result in rather large improvements in blood pressure control - generally, the improvement was greater than would normally be expected by adding an additional medication.
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n this study, 12 patients with resistant hypertension at the University of Alabama were randomized to one of two diets - a 5700 mg per day sodium diet or a 1150 mg per day sodium diet. All patients were treated, in a randomized cross-over pattern, with each of these diets for a period of time. Investigators found that when the patients were on the lower sodium diet, their blood pressures were signficantly improved, by more than 22 mm Hg for systolic, and more than 9 mm Hg for diastolic pressures.

Somewhat surprisingly (since salt restriction has long been a staple of blood pressure control) this small trial was the first time sodium restriction was specifically evaluated in patients with resistant hypertension.

Because the trial was so small, and the duration of the trial was limited to about two weeks, the trial cannot be considered definitive. Undoubtedly, larger, longer-lasting trials will now be designed to test the sodium-restriction hypothesis in patients with restistant hypertension.
But if you are one of the 20+% of patients with high blood pressure who is taking at least three medications with poor blood pressure control, you might want to talk to your doctor about trying a strict limited-salt diet before adding yet another drug.

Sources
Pimenta E, Gaddam KK, Oparil S, et al. Effects of dietary sodium reduction on blood pressure in subjects with resistant hypertension. Results from a randomized trial. Hypertension 2009; DOI: 10.1161/HYPERTENSIONAHA.109.131235.