[Is the low-sodium diet actually indicated for all patients with stable heart failure?].

Background: Although a low-sodium diet is indicated for heart failure HF, there is no evidence this dietary restriction is beneficial to all patients.

Objective: To prospectively study the acute effectsof a low-sodium diet in patients (pts) with heart failure (HF).

Methods: Fifty stable outpatients with mild to moderate HF who reported previously consuming 6.6 g table salt/day were studied. In Phase 1, all pts were submitted to a diet with 2 g of salt during 7 days, followed by randomization in 2 subgroups (Phase 2): one to receive 6 g of salt (subgroup 1) and the other, 2 g of salt/day for 7 days (subgroup II).

Results: Phase 1: the diet with 2 g of salt reduced the BMI, plasma and urinary sodium, protein consumption, iron, zinc, selenium and vitamin B12; it increased plasma levels of norepinephrine, nitrate, serum aldosterone and improved quality of life. Phase 2: for pts with low BMI, the use of 6 g salt/day acutely decreased the levels of norepinephrine, albumin and cholesterol in plasma. No difference was observed in pts with higher BMI.

Conclusion: The diet with 2 g salt/day for pts with HF increased the neurohormonal activation associated to HF progression. The BMI can influence the response to the neurohormonal activation in a low-sodium diet in pts with HF. Further studies to test salt restriction for longer periods are recommended.