Patients With Primary Aldosteronism Respond to Unilateral Adrenalectomy With Long-Term Reduction in Salt Intake

Abstract

Context: High dietary salt intake is known to aggravate arterial hypertension. This effect could be of particular relevance in the setting of primary aldosteronism (PA), which is associated with cardiovascular damage independent of blood pressure levels. The aim of this study was to determine the impact of therapy on salt intake in PA patients.

Patients and methods: A total of 148 consecutive PA patients (66 with unilateral and 82 with bilateral PA) from the database of the German Conn's Registry were included. Salt intake was quantified by 24-hour urinary sodium excretion before and after initiation of PA treatment.

Study design: Observational longitudinal cohort study.

Setting: Tertiary care hospital.

Results: At baseline, unilateral PA patients had a significantly higher urinary sodium excretion than patients with bilateral disease (205 vs 178 mmol/d, P = 0.047). Higher urinary sodium excretion correlated with an increased cardiovascular risk profile including proteinuria, impaired lipid, and glucose metabolism and was associated with higher daily doses of antihypertensive drugs to achieve blood pressure control. In unilateral disease, urinary sodium excretion dropped spontaneously to 176 mmol/d (P = 0.012) 1 year after unilateral adrenalectomy and remained low at 3 years of follow-up (174 mmol/d). In contrast, treatment with mineralocorticoid receptor antagonists (MRA) in bilateral PA patients was not associated with a significant change in urinary sodium excretion at follow-up (179 mmol/d vs 183 mmol/d).

Conclusion: PA patients consuming a high-salt diet, estimated based on urinary sodium excretion, respond to adrenalectomy with a significant reduction of salt intake, in contrast to MRA treatment.

Keywords: adrenalectomy; cardiovascular risk; hypertension; primary aldosteronism; salt intake; sodium excretion.

Figure 1.

Twenty-four-hour urinary sodium excretion at baseline and at 1- and 3-year follow-up in unilateral and bilateral primary aldosteronism.Median and 95% confidence interval are shown. *Significance. Abbreviation: PA, primary aldosteronism.

Figure 2.

Correlation of 24-hour systolic blood pressure with 24-hour urinary sodium excretion at baseline.*Patients carrying KCNJ5 mutation. The dashed line marks an estimated salt intake of 5 g/d as recommended by the World Health Organization. Abbreviation: 24-h SBP, 24-hour systolic blood pressure.

Figure 3.

Changes in 24-hour diastolic blood pressure and proteinuria at 3-year follow-up according to high or low change in 24-hour urinary sodium excretion compared with baseline.Median and 95% confidence interval are shown. *Significance. Abbreviations: 24-h DBP, 24-hour diastolic blood pressure; Δ 24-h DBP, 24-h DBP at 3-year follow-up—24-h DBP at baseline; Δ Proteinuria, proteinuria at 3-year follow-up—proteinuria at baseline.