Aim: Co-existing primary aldosteronism (PA) and autonomous cortisol secretion (ACS) has been recently recognized as a distinct entity. This study aimed to assess the incidence of ACS in patients with PA, and its impact on clinical and laboratory parameters.

Methods: Ninety-two patients diagnosed with PA were included. Demographic data, comorbidities, laboratory and imaging results were retrospectively analyzed. Patients with overnight 1 mg dexamethasone suppression test >1.8 µg/dL were classified as PA with ACS.

Results: Twenty-four patients (26.1%) were in the PA-with-ACS group, and 68 (73.9%) in the PA-without-ACS group. Mean age (p=0.034), body mass index (p=0.034), number of female patients (p=0.012) and maximum adenoma diameter (p<0.001) were higher in the PA-with-ACS group than in the PA-without-ACS group. Basal (p=0.001) and post-saline infusion plasma aldosterone concentrations (PAC) (p=0.009) were higher in the PA-without-ACS group than in the PA-with-ACS group. No significant differences between groups were found in intensity of antihypertensive treatment, presence of type 2 diabetes, coronary artery disease, proteinuria or glomerular filtration rate (p>0.05). Left ventricular hypertrophy (LVH) was detected in 49.4% of patients. Logistic regression demonstrated that PAC and gender were associated factors for LVH.

Conclusion: Cortisol co-secretion was identified in approximately one-quarter of patients diagnosed with PA. PA patients without ACS had higher PAC than those with. Co-existing ACS did not seem to have a significant negative impact on clinical parameters in patients with PA.