Sodium Intake Below Recommended Levels May Increase Mortality in Heart Failure

Restricting dietary sodium intake to below the standard recommended maximum of about 2.3 grams per day does not provide additional benefits and may increase the risk of death in patients with heart failure, according to a meta-analysis of nine randomized controlled trials.

The findings, presented at the American College of Cardiology (ACC) 2023 Annual Scientific Sessions in New Orleans, Louisiana, elucidate the counterproductiveness of cutting sodium intake below current recommendations.

“Our findings showed that restricting dietary sodium to less than the usual recommendation was counterproductive in the management of heart failure,” said Anirudh Palicherla, MD, an internal medicine resident at Creighton University School of Medicine, and the study’s lead author. “This was in line with a recent randomized controlled trial suggesting that restricting sodium more than what we do now doesn’t necessarily lead to better outcomes.”

A low-sodium diet is physician-recommended to reduce blood pressure and avoid common symptoms including fluid buildup and swelling. Mixed results from previous studies, however, have made it unclear on the optimal maximum daily sodium intake for patients with heart failure.

Currently, the US Dietary Guidelines for Americans recommend a maximum dietary sodium intake of 2.3 grams per day for adults. However, the average American consumes over 3.4 grams of sodium per day. investigators in the current meta-analysis analyzed nine randomized controlled trials that assessed different levels of sodium restriction versus usual care for patients with heart failure.

The search of multiple databases revealed most of the studies were conducted between 2008 and 2022, aside from a single study published in 1991. Overall, the 9 trials enrolled approximately 3,500 patients with heart failure. Investigators used a random-effects model to calculate risk ratios (RRs) and 95% confidence intervals (CIs).

Compared with usual care, the results showed that patients following a diet with a sodium intake target below 2.5 grams per day were 80% more likely to die than those following a diet with a target of 2.5 grams per day or more (RR, 1.84; 95% CI, 1.46 - 2.31; P <.001). There were no significant differences in hospitalizations observed between the two groups (RR, 1.45; 95% CI, 0.99 - 2.11; P = .05), according to the data.

Investigators noted there was significant variability in the study designs used in the clinical trials, including participant baseline characteristics, healthcare settings, and methods for tracking sodium intake and health outcomes. Additionally, some studies required fluid intake restriction in addition to sodium intake and others did not.

Palicherla and colleagues added that the number of studies and the number of participants give the researchers a high level of confidence in the overall findings.

“Limiting sodium is still the way to go to help manage heart failure, but the amount of restriction has been up for debate,” Palicherla said. “This study shows that the focus should be on establishing a safe level of sodium consumption instead of overly restricting sodium.”

References

1. Palicherla A. Sodium Restriction in Heart Failure: A Meta-Analysis of Randomized Trials. American College of Cardiology (ACC) 2023 Annual Scientific Sessions. In: New Orleans, Louisiana.