Autonomous cortisol secretion promotes vascular calcification in vivo and in vitro under hyperaldosteronism

Autonomous cortisol secretion (ACS) is not uncommon in patients with primary aldosteronism (PA). However, the cardiovascular burden of ACS due to its dysregulated cortisol secretion remains poorly understood. Thus, we examined the effects of ACS on vascular calcification in a hyperaldosteronism environment in vitro and in vivo. A total of 339 patients with PA with adrenal incidentaloma and low-dose dexamethasone suppression test data (cutoff level: cortisol > 1.8 μg/dL) from a prospectively maintained database were enrolled; abdominal aortic calcification (AAC) scores were quantitatively estimated. Human aortic smooth muscle cells (HAOSMCs) were used as in vitro model of vascular calcification. In this study, 65 of the 339 patients with PA had ACS; 274 did not. Patients with PA/ACS had a higher AAC score (1171.0 ± 2434.0 vs. 489.5 ± 1085.3, P = 0.012) than patients without ACS. ACS was independently associated with AAC score (β = 0.139, P = 0.004) in multivariate analysis, and post-suppression cortisol level was significantly correlated with the AAC score (P = 0.004). In the HAOSMC model, co-treatment with cortisol synergistically stimulated alkaline phosphatase activity and calcium deposition in a hyperaldosteronism environment. The stimulatory effect of cortisol was abolished by the mineralocorticoid receptor (MR) antagonist eplerenone, but not glucocorticoid receptor antagonist mifepristone, indicating a MR-dependent mechanism. In conclusion, the presence of ACS is associated with heavier vascular calcification in patients with PA. Aldosterone and cortisol synergistically activate HAOSMC calcification via MR signaling, via a process that can be attenuated by eplerenone.