Too little salt intake can lead to heart failure

Restricting salt intake is considered a key part of treating heart failure, but restricting it too much may actually worsen outcomes for people with a common form of the disease, suggests research published in review “Heart” .

Young people and those of black and other ethnicities appear to be at greater risk, the findings show.

Sodium restriction is frequently recommended in heart failure guidelines, but the optimal range of restriction (less than 1.5 g to less than 3 g per day) and its effect in heart failure patients with a fraction of ‘preserved ejection’ are unclear, as they have often been ruled out. relevant studies.

Heart failure with preserved ejection fraction, which accounts for half of all cases of heart failure, occurs when the lower left chamber of the heart (left ventricle) is unable to fill adequately with blood (diastolic phase), which which reduces the amount of blood pumped to the body.

In an attempt to further explore the association with salt intake, the researchers relied on a secondary analysis of data from 1,713 people aged 50 and over with heart failure with preserved ejection fraction who were part of of the TOPCAT test.

This trial was designed to determine if the drug spironolactone could effectively treat symptomatic heart failure with preserved ejection fraction.

Participants were asked how much salt they typically add to staples such as rice, pasta and potatoes; Soup; meat; and vegetables, and it was scored as follows: 0 points (none); 1 (⅛ teaspoon); 2 (¼ teaspoon); and 3 (½ + teaspoon).

Their state of health was then monitored for an average of 3 years for the main criterion, a composite of death from cardiovascular disease or hospital admission for heart failure plus abortive cardiac arrest. Secondary outcomes of interest were all-cause death and death from cardiovascular disease plus hospital admission for heart failure.

About half of the participants (816) had a table salt score of zero: more than half were male (56%) and the majority were Caucasian (81%). They weighed significantly more and had lower diastolic blood pressure (70 mm Hg) than those with a cooking salt score above zero (897).

They had also been admitted to hospital more often for heart failure, were more likely to have Type 2 diabetesnail lower kidney functionare taking medicines to control your heart failure and have a reduced left ventricular ejection fraction (decreased cardiac output).

Participants with a cooking salt score greater than zero had a significantly lower risk of this outcome than those with a score of zero, primarily because they were less likely to be hospitalized for heart failure. But they were no less likely to die of a cardiovascular cause or disease than those with a cooking salt score of zero.

People aged 70 or younger had significantly more likely to benefit from adding salt to your cooking than people over 70 in terms of primary endpoint and hospitalization for heart failure.

Similarly, blacks and other ethnic people seemed to benefit more from adding salt to their cooking than whites, although the numbers were small.

Gender, prior hospitalizations for heart failure, and use of heart failure medications were not associated with increased risks for any of the outcomes measured and the kitchen salt score.

This is an observational study and as such cannot establish cause. Not all relevant test data TOPCAT were available, while the cooking salt score was self-reported, the researchers acknowledge. And reverse causation cannot be ruled out, whereby less healthy people could have been instructed to further restrict their salt intake.

Low sodium intake is generally associated with low blood pressure and a reduced risk of cardiovascular disease in the general public and people with high blood pressure. It is believed to reduce water retention and the activation of hormones involved in blood pressure regulation.

But restricting salt intake to control heart failure is less straightforward, the researchers say. May cause intravascular volume contraction, which in turn may reduce congestion and the need for diuretics to relieve fluid retention.

But the results of their study show that blood plasma volume, an indicator of congestion, was not significantly associated with table salt score, suggesting that low sodium intake did not ameliorate salt retention. water in people with heart failure preserved ejection fraction, the researchers note.

“Excessive restriction of dietary salt intake could harm patients with [insuficiencia cardíaca con fracción de eyección preservada] and is associated with a worse prognosis. Physicians should reconsider giving this advice to patients.”

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