Pattern of Adrenal Hormonal Secretion in Patients with Adrenal Adenomas: The Relevance of Aldosterone in Arterial Hypertension

CONTEXT: Approximately 10% of hypertensives are considered to exhibit autonomous aldosterone secretion (AAS). Although adrenal incidentalomas (AI) can be found in up to 19% of hypertensive individuals, data on the incidence of AAS in hypertensive patients with AI remain scarce. OBJECTIVE: The aim was to study adrenal aldosterone (ALD) secretory pattern in patients with adrenal adenomas with and without arterial hypertension. DESIGN AND SETTING: We conducted a case-control study in a tertiary general hospital. PATIENTS AND MAIN OUTCOME MEASURES: 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). Evaluation of autonomous cortisol secretion was based on a low-dose dexamethasone suppression test. Autonomous ALD secretion was based on a modified saline infusion test (MSI). Normal cutoff levels were obtained from the control matched population. RESULTS: Post-MSI ALD levels and the ALD/renin (REN) ratios were significantly elevated in HAI and HAA patients compared to NAI subjects. To evaluate the prevalence of AAS, we applied the combination of post-MSI ALD level and the ALD/REN ratio simultaneously (post-MSI cutoffs, ALD levels, 2.41 ng/dl; ALD/REN ratio, 0.35 ng/dl/μU/ml). Based on these cutoffs, 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. CONCLUSIONS: Using a MSI test, we found a remarkably increased prevalence of AAS in hypertensive patients with adrenal adenomas, even when the latter represented an incidental finding.