Moderate salt restriction lowers BP, weight in patients with primary aldosteronism

Key takeaways:

• Moderately restricting salt intake decreased both diastolic and systolic BP in patients with primary aldosteronism.
• Further improvements were seen in patients’ weight and mental health.

A recent study found that moderate salt restriction was associated with substantial reductions in BP and depressive symptoms in patients with primary aldosteronism.

Because of the aldosterone excess in patients with primary aldosteronism (PA), “salt appetite is impaired, which facilitates high dietary salt intake,” Holger Schneider, DrMed, a researcher at Ludwig Maximilian University of Munich, and colleagues wrote in the Journal of Internal Medicine.

The researchers wrote that the combination of aldosterone excess and high dietary sodium intake in patients with PA means these patients are faced with “persistently” elevated cardiovascular risks.

“A moderate restriction of dietary salt intake holds promise to allow for relevant BP reduction, whereas at the same time, not risking patient adherence because of an inconveniently low prescribed dietary sodium intake,” they wrote.

Schneider and colleagues analyzed data from 41 participants with PA who were assigned to a moderate dietary salt restriction for 12 weeks. The cohort had a mean age of 50 years, and 23 were women.

Participants received personally structured nutritional training at baseline and were supported by both a dietician and nutritional mobile app throughout the study period. The researchers measured diet adherence every 4 weeks with two consecutive 24-hour urinary sodium excretion and nutrition protocols.

Schneider and colleagues found that dietary salt intake decreased from 9.1 g per day at baseline to 5.2 g per day by the end of the study period. Patients additionally saw improvements in systolic BP, which declined from 130 mmHg to 121 mmHg, and diastolic BP, which dropped from 84 mmHg to 81 mmHg.

The dietary restriction was also associated with:

• improved patient aptitude of estimating dietary salt content, from 2.4 g to 1.4 g per day;
• a weight loss of 1.4 kg;
• improved pulse pressure, from 46 mmHg to 40 mmHg; and
• improved mental well-being, particularly depressive symptoms.

Overall, the 9 mmHg reduction in systolic BP and 60 mmol reduction in salt intake translated to a reduction of 7 mmHg per 50 mmol, “which is a comparatively modest and very patient-friendly reduction,” Schneider and colleagues wrote.

“The achieved effect equates to one additional fully dosed anti-hypertensive drug,” they wrote.

Notably, while both genders reduced estimated salt intake by a comparable amount and started from a comparable level of systolic and diastolic BP, “male sex was associated with a significantly better BP reduction to salt restriction,” the researchers wrote.

Schneider and colleagues noted that dietary salt is a factor that should be monitored in all patients with PA, and guidance and education helped to enhance participants’ understanding of dietary salt intake.

“This strategy represents a cost-effective, low-threshold measure which at the same time reduces BP and pill burden and empowers patients to take responsibility for their own health,” they concluded.

References:

• Can moderate dietary salt restriction help patients with hypertension? https://www.eurekalert.org/news-releases/983073. Published March 22, 2023. Accessed March 23, 2023.
• Schneider H, et al. J Intern Med. 2023;doi:10.1111/joim.13618