Endocrine Abstracts

JOINT1188

Introduction: Mild autonomous cortisol secretion (MACS) is diagnosed, based on an abnormal overnight 1 mg dexamethasone suppression test, in 20-50% of patients with adrenal adenomas without signs of Cushing syndrome. MACS is associated with cardiovascular morbidity, fragility fractures, decreased quality of life and increased mortality. Management of MACS should be individualized based on patient characteristics and include adrenalectomy or conservative follow-up with treatment of associated comorbidities.

Aim: To retrospectively compare the comorbidities and the management between a cohort of cases with MACS and non-functional adenomas (NFA) admitted at least yearly in a tertiary institution, between 2019-2023.

Patients and Methods: 229 patients (170 women, 59 men) were evaluated for adrenal lesions. 135 patients were included in the study after exclusion of other adrenal functional lesions. Adrenal function was assessed by basal and dynamic cortisol (suppression tests) and ACTH, testosterone, DHEA-S, aldosterone and renin, urinary and plasma metanephrines and normetanephrines.

Results: In the MACS group 34 patients were included with a ratio of almost 1:3 for the non-functional adenoma group (n = 101 patients). 11 patients (7 left nodules + 4 right nodules) in the MACS group underwent surgery vs 4 patients in the NFA group. The criteria for surgery were the radiological features [Hounsfield units, biggest nodule or the easiest surgical approach (if bilateral)]. There were 2 cases of post-operatory transient adrenal insufficiency (evaluated with 1 ug short Synacthene testing), 1 case of residual cortisol secretion after surgery (surveillance decided). The mean follow-up duration was 4.8 years (±3.06). All the other patients had normal hormonal work-up after surgery. When discussing comorbidities: the MACS group had a higher rate of dyslipidemia of 85.3% vs 67.3% in the NFA group (P = 0.049), a higher prevalence of hypertension: 82.4% vs 59.4% in the NFA group (P = 0.021) and a higher prevalence of diabetes mellitus: 32.4% vs 13.9% (P = 0.022). Interestingly, the MACS group showed greater dimensions of the adrenal lesions than the NFA group in transverse and antero-posterior computed tomography measurements (p<0.023).

Conclusion: The detailed continuous clinical and biochemical follow-up every 6-12 months of patients with MACS is necessarily for proper and individualized management, especially for evaluating and modifying the treatment of comorbidities.