Autonomous cortisol secretion in adrenal incidentalomas and increased visceral fat accumulation during follow-up

Objective: Autonomous cortisol secretion of adrenal incidentalomas (AIs) is associated with poor cardiovascular outcome. Because centripetal obesity is a cardiovascular risk factor, we aimed to investigate whether autonomous cortisol secretion is associated with increased visceral fat accumulation. Design: Retrospective cohort study. Patients: Patients with AIs who attended for follow-up between January 2014 and December 2016 were evaluated. Autonomous cortisol secretion was diagnosed when 1mg overnight dexamethasone (post-DST) cortisol was >50nmol/L at baseline and follow-up. Follow-up duration was 34 (12-105) months. Thirty patients with nonfunctioning AIs and 44 patients with autonomous cortisol secretion were included. Adrenalectomy was performed in five patients. Six patients with Cushing's syndrome were also recruited. Measurements: Hormonal evaluation and assessment of total (T), visceral (V) and subcutaneous (S) fat area by computed tomography and calculation of V:S and V:T ratios at baseline and follow-up. Results: V, V:S and V:T increased (P<.001 for each comparison, Wilcoxon signed rank test for repeated measures) in patients with autonomous cortisol secretion while did not change significantly in patients with nonfunctioning adenomas. Linear regression models including post-DST cortisol, gender, concomitant treatments and follow-up duration showed that both baseline and follow-up DST significantly predicted (V:S) and (V:T) (P<.01 for all models). Conclusions: In patients with AIs, a post-DST cortisol >50nmol/L at both baseline and follow-up, was associated with a significant increase in visceral fat after a follow-up duration of similar to 3years. This may be of importance to explain the link between autonomous cortisol secretion and poor cardiovascular outcome.