Moderate dietary salt restriction improves blood pressure and mental well‐being in patients with primary aldosteronism: The salt CONNtrol trial

Abstract

Background Primary aldosteronism (PA) is a frequent cause of hypertension. Aldosterone excess together with high dietary salt intake aggravates cardiovascular damage, despite guideline‐recommended mineralocorticoid receptor antagonist (MRA) treatment. Objectives To investigate the antihypertensive impact of a moderate dietary salt restriction and associated physiological changes, including mental well‐being. Methods A total of 41 patients with PA on a stable antihypertensive regimen—including MRA—followed a dietary salt restriction for 12 weeks with structured nutritional training and consolidation by a mobile health app. Salt intake and adherence were monitored every 4 weeks using 24‐h urinary sodium excretion and nutrition protocols. Body composition was assessed by bioimpedance analysis and mental well‐being by validated questionnaires. Results Dietary salt intake significantly decreased from 9.1 to 5.2 g/d at the end of the study. In parallel, systolic (130 vs. 121 mm Hg) and diastolic blood pressure (BP) (84 vs. 81 mm Hg) improved significantly. Patients’ aptitude of estimating dietary salt content was refined significantly (underestimation by 2.4 vs. 1.4 g/d). Salt restriction entailed a significant weight loss of 1.4 kg, improvement in pulse pressure (46 vs. 40 mm Hg) and normalization of depressive symptoms (PHQD scale, p < 0.05). Salt restriction, cortisol after dexamethasone suppression test and dosage of renin‐angiotensin‐aldosterone‐system (RAAS) blockers were independently associated with BP reduction. Conclusion A moderate restriction of dietary salt intake in patients with PA substantially reduces BP and depressive symptoms. Moreover, the findings underline that a sufficient RAAS blockade seems to augment the effects of salt restriction on BP and cardiovascular risk.

Long-Term Follow-Up of Patients With Elevated Aldosterone-to-Renin Ratio but Negative Confirmatory Test: The Progression of Primary Aldosteronism Phenotypes

“…This is not surprising, considering the renin variability that is observed in patients without PA, 26 justified by several factors, in particular dietary sodium intake. 27,28 However, at least in our study, dietary sodium intake estimated by 24-hour urinary sodium excretion was unaltered at follow-up.…”

Dietary salt restriction in primary aldosteronism

“…The effect of sodium restriction on blood pressure in persons with PA in the study by Schneider et al is thus substantially larger than in studies on primary hypertension [5]. This is a very interesting and encouraging finding.…”

“…Several other findings are also of interest in the study by Schneider et al [5]: (a) A mean weight loss of 1.4 kg was achieved after 12 weeks of dietary salt reduction, reflecting loss of body water; (b) pulse pressure, a surrogate variable used to evaluate arterial stiffness, decreased from 46 to 40 mmHg; (c) symptoms of depression and anxiety, evaluated with validated questionnaires, improved; and (d) salt taste threshold decreased from 32 to 21 mmol/L. Salt taste threshold was evaluated by letting the patients taste solutions containing different concentrations of NaCl and compare to distilled water.…”

“…In conclusion, given the positive effect on blood pressure in the study by Schneider et al, as well as positive effects on symptoms of depression and anxiety, a moderate dietary restriction should be considered in patients with PA [5]. The results from trials in persons with primary hypertension show the importance of comprehensive counseling about salty food and feedback from 24-h sodium excretion when salt restriction is used for therapeutic purposes.…”

“…In this context, a paper recently published in the Journal of Internal Medicine by Schneider et al in Munich, Germany, is of special interest [5]. The effect of a 12-week dietary salt restriction on blood pressure was assessed in 41 patients with PA who were all receiving medical treatment with a mineralocorticoid receptor antagonist.…”