Abstract
Objective: Describe the secretion and profile of adrenal steroids in patients with adrenal incidentalomas compared to control subjects. Design, Setting and Participants: A prospective study, 73 patients with adrenal incidentalomas, 21 bilateral and 52 unilateral and 34 matched controls in University Hospital. Methods: Collect fasting blood sample before and 60 min after ACTH test (250 µg IV). One week later, perform overnight 1 mg dexamethasone test. The following steroids were measured by liquid chromatography-mass spectrometry (LC-MS): pregnenolone, 17-OH pregnenolone, 17-OH progesterone, 11-deoxycorticosterone, 11-deoxyortisol, 21-deoxycortisol, corticosterone, cortisol, androstenedione and aldosterone. Results: Mean baseline serum cortisol was higher in incidentalomas, bilateral 361 ± 124, (range 143–665) nmol/L,(p <.0001), unilateral 268 ± 89 3.2 (range 98–507) nmol/L (p <.019) compared to controls 207 ± 100 (range 72–502) nmol/L. ACTH stimulation showed significantly higher levels in bilateral and unilateral cases compared to controls. After dexamethasone, mean serum cortisol levels suppressed in bilaterals 89 ± 69 (range 30–3) nmol/L (p <.0001), 58 ± 52 (range 16–323) nmol/L in unilateral (p <.01) compared to 26 ± 9 (range 7–46) nmol/L in controls. Mean baseline serum corticosterone was higher in bilateral 9.3 ± 4.8 (range 2.4–18.4) nmol/L (p <.005) and unilateral 7.3 ± 5.7 (range 0.1–30.3) nmol/L (p <.01) compared to controls 4.2 ± 2.4 (range 1.1–10.2) nmol/L, after ACTH stimulation significantly increased to higher levels in bilateral (p <.0002) and unilateral cases (p <.044) compared to controls. After dexamethasone, mean levels were 2.5 ± 2.6 (range 0.5–12.5) nmol/L in bilateral (p <.0006), 1.5 ± 1.6 (range 0.3–9.3) nmol/L in unilateral (p <.09) and 0.75 ± 0.46 (range 0.1–2.1) nmol/L in controls. Mean baseline serum 11-deoxycorticosterone (DOC) was higher in bilaterals 0.32 ± 0.23 (range 0.08–1.1) nmol/L (p <.03) compared to controls 0.15 ± 0.21 (range 0.08–1.1) nmol/L. ACTH stimulation increased levels to 3.27 ± 1.72 (range 0.5–7.4) nmol/L in bilateral cases compared to controls 1.369 ± 1.53 (range 0.1–7.1) nmol/L (p <.0001). Dexamethasone decreased levels to baseline (p ns). There were significant differences in serum 21-deoxycortisol (p <.0002) and serum pregnenolone (p <.004) only after ACTH stimulation. Conclusions: There is increased activity in several steroid biosynthesis pathways and higher steroid levels in bilateral compared to unilateral cases and evidence of hypercortisolism in 30% unilateral and 62% of bilateral incidentalomas.