Endocrine Abstracts

Background: Hormonal activity and insulin resistance (IR) in patients with incidentally discovered bilateral adrenal adenomas (BA) has not been evaluated until now. Therefore, we have investigated cortisol and aldosterone secretion and IR in 29 patients with BA, in 113 patients with unilateral adrenal adenomas (UA) and in 89 healthy subjects (C).

Methods: All subjects underwent the following investigation: 1) Low dose dexamethasone suppression test (LDDST) (0.5 mg DEX/6 h for 2 days) to access cortisol secretion, 2) NaCl (0.9%) infusion test (INF) (2lt NaCl 0.9% i.v. in 4 h) following LDDST to access aldosterone secretion, 3)2 h Oral Glucose tolerance test (OGTT) (75 g) with glucose and insulin measurements every 30 min. Homa ((fasting glucose (mmol/l)*fasting insulin (μIU/ml))/22.5) and Matsuda index{10 000/square root ((fasting glucosexfasting insulin)*(mean OGTT glucose*mean OGTT insulin)} were calculated for IR assessment.

Results: Cortisol and aldosterone cut-offs based on mean±2 S.D. values in CT group were calculated following LDDST and infusion test respectively. (cortisol cut-off: 34.11 (nmol/l) and aldosterone cut-off: 74.83 (pmol/l)). Autonomous cortisol or aldosterone secretion was found in 61.58 and 33.74% of patients with UA and in 65 and 28% of patients with BA respectively, whereas autonomous concomitant cortisol and aldosterone secretion was documented in 15.68% of patients with UA and 21% of patients with BA. The results of the performed tests are summarized below. ((mean±S.E.M.), cortisol (nmol/l) aldosterone (pmol/l)).

Conclusions: Autonomous cortisol and aldosterone secretion in patients with UA is more common than previously described. Hormonal activity of patients with BA is described for the first time. Patients harbouring BA appear to have more pronounced autonomous cortisol and aldosterone secretion and increased IR than patients with UA.