Long-term effects of dietary sodium intake on cytokines and neurohormonal activation in patients with recently compensated congestive heart failure.

BACKGROUND: A growing body of evidence suggests that the fluid accumulation plays a key role in the pathophysiology of heart failure (HF) and that the inflammatory and neurohormonal activation contribute strongly to the progression of this disorder.

METHODS AND RESULTS: The study evaluated the long-term effects of 2 different sodium diets on cytokines neurohormones, body hydration and clinical outcome in compensated HF outpatients (New York Heart Association Class II). A total of 173 patients (105 males, mean age 72.5+/-7) recently hospitalized for worsening advanced HF and discharged in normal hydration and in clinical compensation were randomized in 2 groups (double blind). In Group 1, 86 patients received a moderate restriction in sodium (120mmol to 2.8g/day) plus oral furosemide (125 to 250mg bid); in Group 2, 87 patients: received a low-sodium diet (80mmol to 1.8g/day) plus oral furosemide (125 to 250mg bid). Both groups were followed for 12 months and the treatment was associated with a drink intake of 1000mL daily. Neurohormonal (brain natriuretic peptide, aldosterone, plasma rennin activity) and cytokines values (tumor necrosis factor-alpha, interleukin-6) were significantly reduced with a significant increase of the anti-inflammatory cytokine interleukin-10 at 12 months in normal, P < .0001) than low-sodium group. The low-sodium diet showed a significant activation of neurohormones and cytokines and worsening the body hydration, whereas moderate sodium restriction maintained dry weigh and improved outcome in the long term.

CONCLUSIONS: Our results appear to suggest a surprising efficacy of a new strategy to improve the chronic diuretic response by increasing Na intake and limiting fluid intake. This counterintuitive approach underlines the need for a better understanding of factors that regulate sodium and water handling in chronic congestive HF. A larger sample of patients and further studies are required to evaluate whether this is due to the high dose of diuretic used or the low-sodium diet.