OSA in primary aldosteronism patients improves with adrenalectomy, medication
Obstructive sleep apnoea (OSA) is common among patients with primary aldosteronism (PA), and adrenalectomy or medical therapy for PA appears to be associated with marked improvements in the sleep disorder, a study has found.
The study included 34 patients with PA (median age 50 years; 61.8 percent male; median body mass index >30 kg m-2) who underwent polysomnography at baseline and after 3 months after treatment.
OSA was not evident in 21 percent of PA patients (apnoea-hypopnea index [AHI] <5), mild in 26 percent (AHI ≥5 and <15), moderate in 24 percent (AHI ≥15 and <30), and severe in the remaining 29 percent (AHI ≥30). AHI correlated with body mass index tertiles, neck circumference and 24-hour urinary sodium.
In 20 patients who underwent repeat polysomnography following treatment for PA—including mineralocorticoid receptor antagonists in 13 patients with bilateral PA and adrenalectomy in seven with unilateral PA—median AHI significantly decreased from 22.5 to 12.3 (p=0.02). A small reduction in neck circumference was also observed with PA treatment (41.6 vs 41.2 cm; p=0.012).
Researchers noted that the present data indicate that OSA in the study population is primarily driven by anatomical factors and aggravated by aldosterone excess in a salt-dependent manner, possibly by inducing increased airways oedema.
Primary aldosteronism is believed to cause hypertension largely through the promotion of sodium and fluid retention. Retention of fluid has been also shown to promote oedema of the soft tissues of the upper airway, thus causing or worsening OSA and providing a plausible mechanistic link. This is supported by the suggestion of a salt dependency in the aldosterone–OSA relationship. [Hypertension 2012;59:167–172; Sci Rep 2015;5:15297; Chest 2013;143:978–983]