Endocrine Abstracts

Introduction: Autonomous aldosterone secretion (AAS) is present in approximately 10% of hypertensives. Adrenal incidentalomas (AI) can be found in up to 19% of hypertensive individuals. However, data on the incidence of AAS in hypertensive patients with AI is scarce. Our aim was to evaluate the adrenal aldosterone secretory profile in patients with adrenal adenomas with and without arterial hypertension.

Patients and methods: We investigated 72 normotensive subjects with normal adrenal morphology and 191 subjects divided in three groups: 46 normotensive individuals with an AI (NAI), 89 hypertensive patients with an AI (HAI) and 56 hypertensive patients with an adrenal adenoma identified after investigation for arterial hypertension (HAA). All patients underwent a low dose dexamethasone suppression test to assess the presence of autonomous cortisol secretion. The diagnosis of autonomous aldosterone secretion was based on a modified saline infusion test (MSI), i.e. following overnight dexamethasone administration to suppress ACTH-induced aldosterone secretion.

Results: To evaluate the prevalence of AAS, we applied the following cut-offs: post MSI aldosterone (ALD) levels: 2.41 ng/dl and the aldosterone/renin (ALD/REN) ratio: 0.35 ng/dl/μU/ml). Based on these cut-offs, 12% of NAI, 36.4% of HAI and 54.2% of HAA patients had AAS. The prevalence of autonomous cortisol secretion did not differ among the three groups. Post MSI aldosterone levels and the aldosterone/renin ratios were significantly elevated in HAI and HAA patients compared to NAI subjects (Figure 1).

Conclusions: Using the MSI test, we found a remarkably increased prevalence of AAS in hypertensive patients with adrenal adenomas, even when the latter present an incidental finding.

Figure 1 Comparison of aldosterone levels among the control and the three patients’ groups. ALD-B: basal aldosterone levels. ALD-A: aldosterone levels following the modified saline infusion test. C: control group. NAI: normotensive patients with adrenal incidentalomas. HAI: hypertensive patients with adrenal incidentalomas. HAA: hypertensive patients with adrenal adenomas identified during investigation for arterial hypertension.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.