Mild Autonomous Cortisol Secretion in Primary Aldosteronism Enhances Renal and Hemorrhagic Cerebrovascular Complications

Abstract Background: It is well known that primary aldosteronism (PA) is often associated with renal dysfunction and cardiovascular events (CVEs). However, the synergic effect of mild autonomous cortisol secretion (MACS) on the co-morbidities among PA has not been clarified yet. Thus, we retrospectively assessed whether the presence of MACS in PA patients with adrenal tumor, which may have MACS, to enhance the risk of the complications using a large Japanese multicenter database. Methods: We enrolled patients with both confirmed PA and obvious adrenal tumor (diameter > 1 cm) on computed tomography. The subtype of PA was diagnosed based on the results of adrenal venous sampling with ACTH stimulation. A total of 575 study subjects were stratified into two groups according to 1-mg dexamethasone suppression test (DST) results (cut-off post-DST serum cortisol 1.8 µg/dL): MACS group (N=174, 30.2%) and non-MACS group (N=401, 69.8%). Decreased estimated glomerular filtration rate (eGFR) was defined as <60 ml/min per 1.73m2. Results: The percentage of unilateral PA between the MACS and non-MACS group was equivalent (50.0% vs. 48.1%). Prevalence of decreased eGFR in the MACS group was higher than in the non-MACS group [odds ratio (OR) 1.91, 95% confidence interval (95% CI) 1.20–3.04, P=0.006]. Conversely, prevalence of MACS was higher in patients with decreased eGFR than those without decreased eGFR (42.7% vs 28.0%, P=0.008). Proteinuria was deteriorated with the increase in post-DST serum cortisol concentration as well as the basal plasma aldosterone concentration (PAC) (P=0.028 and P<0.001, respectively), although PAC but not the presence of MACS was selected as an independent factor related with decreased eGFR. Prevalence of cerebral hemorrhage in the MACS group was higher than the non-MACS group. (OR 5.35, 95%CI 1.83–15.6, P=0.002). We found that MACS was the only significant factor which increased the odds of developing cerebral hemorrhage (OR 9.13, 95%CI 2.15–38.90, P=0.003). Prevalence of other CVEs between the two groups was similar. Regardless of the PA subtype, complication rate of decreased eGFR and cerebral bleeding in the MACS group were significantly or tend to be higher than non-MACS group. Conclusion: Our date strongly suggested that co-secretion of cortisol in PA directly and/or indirectly increase renal and cerebrovascular comorbidities. Given that MACS is common in PA, endocrinological testing with DST is recommended in PA patients, especially those with adrenal tumor on imaging. (Supported by Research Grants of AMED:JP17ek0109122, JP20ek0109352; National Center for Global Health and Medicine:27–1402, 30–1008), and Ministry of Health, Labour, and Welfare, Japan (046).