Too Little Sodium Can Be Deadly to Heart Failure Patients
By AMERICAN COLLEGE OF CARDIOLOGY
Heart failure, in which the heart
muscle becomes too weak or stiff to pump blood effectively, is a chronic
condition affecting over 6 million adults in the U.S. Physicians recommend a
low-sodium diet to reduce blood pressure and avoid common symptoms such as
fluid buildup and swelling. However, previous studies have reported mixed
results regarding the optimal maximum daily sodium intake for people with heart
failure.
“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 in Omaha, Nebraska, 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.”
The U.S. Dietary Guidelines for
Americans recommends that most adults limit dietary sodium intake to 2.3 grams
per day or less, equivalent to about one teaspoon of table salt. The average
American consumes over 3.4 grams of sodium per day.
In the study, researchers analyzed
nine randomized controlled trials that assessed different levels of sodium
restriction for people with heart failure and included data on rates of death
and hospitalization. Most of the studies were conducted between 2008-2022,
except for one earlier study published in 1991. Together the trials enrolled
nearly 3,500 heart failure patients in total.
Analyzing outcomes across all
studies, researchers found 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. The sodium limits varied
from about 1.2-1.8 grams per day in the more restrictive study arms. The
analysis did not show a trend toward increased hospitalizations among patients
following more restrictive diets.
“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.”
The researchers said that there
was significant variability in the study designs used in the clinical trials,
including different participant baseline characteristics, different health care
settings and different methods for tracking sodium intake and health outcomes.
Some studies required participants to restrict their fluid intake in addition
to their sodium intake, while other studies did not. However, Palicherla said
that the number of studies and total number of participants gives the
researchers a high level of confidence in the overall findings.
Future studies could help clarify
the optimal targets for dietary sodium or identify subgroups of heart failure
patients who might benefit from more or less restriction, researchers said. To
limit sodium intake, experts recommend eating more fresh fruits and vegetables
and cooking with basic ingredients rather than processed, boxed and canned
foods and sauces that often contain high amounts of sodium. When eating out or
buying prepared foods, ask for nutrition information or read the food labels
and choose items with the lowest amounts of sodium.
Palicherla will present the
study, “Sodium Restriction in Heart Failure: A Meta-Analysis of Randomized
Trials,” on Sunday, March 5, at 11:15 a.m. CT / 17:15 UTC in Heart Failure and
Cardiomyopathies Moderated Poster Theater 11, Hall F.
