High prevalence of autonomous cortisol and aldosterone secretion from adrenal adenomas

P>Objectives Previous studies based on standard endocrine testing have shown a variable incidence of autonomous cortisol secretion (ACS) or autonomous aldosterone secretion (AAS) in patients with single adrenal adenomas (SAA). We tested whether the use of appropriate controls and modification of standard testing, aiming at eliminating interference from endogenous ACTH, reveals previously undetected subtle ACS and AAS by SAA. Design Case control study. Patients We investigated 151 patients with SAA and 72 matched controls with normal adrenal computerized tomography. Measurements All participants had arterial blood pressure recorded, and serum cortisol and aldosterone measured before and after intravenous administration of 250 mu g of ACTH, and following dexamethasone administration. Eighty-three patients and all the controls had serum aldosterone and renin measured before and after saline infusion, and after a second saline infusion following dexamethasone administration. Results Using the mean + 2 SD values obtained from controls after dexamethasone administration and saline infusion following dexamethasone administration, normal cut-off values for cortisol (30 center dot 11 nm), aldosterone (67 center dot 59 pm), and aldosterone/renin ratio (9 center dot 74 pm/mU/l) were developed. Using these cut-off values, the estimated incidence of ACS and AAS in patients with SAA was 56 center dot 63% and 24 center dot 10%, respectively, whereas 12 center dot 05% had autonomous secretion of both cortisol and aldosterone. Systolic and diastolic arterial blood pressure correlated significantly with the aldosterone/renin ratio following Alpha CTH stimulation (P < 0 center dot 0002 and P < 0 center dot 001, respectively), and after saline infusion following dexamethasone administration (P < 0 center dot 003 and P < 0 center dot 002, respectively). Conclusions By applying new cut-offs, ACS and AAS in patients with a SAA is very common, and aldosterone secretion correlates with arterial blood pressure.