Endocrine Abstracts

Introduction: Mild hyperkalemia is a common side-effect of mineralocorticoid receptor antagonists (MRA), which can be precipitated by minimizing dietary salt intake. Restoration of salt intake can overcome diminished kaliuresis and restore potassium levels. Aim of this study was the evaluation of the effect of adequate salt consumption on plasma potassium levels in relation to the mean, maximum and minimum blood pressure (BP) in MRA-treated sodium-depleted hyperkalemic patients with primary aldosteronism (PA).

Description of methods/design: Nine MRA-treated sodium-depleted PA patients (67.7±9.7 years of age) were recruited. BP was documented by the patients and renin (plasma), aldosterone (plasma), potassium and sodium (plasma and 24 h urine) levels were measured while patients were following a sodium-restricted diet and after one month of adequate dietary salt supplementation (4 g of salt/day).

Results: Salt supplementation (24 h urine sodium: 199.39±50.46 vs 101.06±41.78 mmol/d) increased kaliuresis (68.9±21.7 vs 54.21±17.6 mmol/d, P<0.001) and resulted in a statistically significant decrease of potassium (4.64±0.34 vs 5.28±0.26 mmol/l, P<0.001), renin (43.2±47 vs 53±48.5 pg/ml, P=0.004) and aldosterone (1603±1670 vs 2435±1667 pmol/l, P=0.015) levels, without affecting plasma sodium levels (138.4±2.65 vs 138±2.69 mmol/l), mean diastolic or systolic BP (128.3±10.6 vs 129.2±10.2 and 71±7.6 vs 71.1±7.5 mmHg, respectively) or minimum and maximum BP values.

Conclusion: Adequate salt intake can attenuate MRA-induced hyperkalemia in sodium-depleted PA patients without short term effects on BP.