The impact of adrenalectomy on metabolic outcomes of patients with mild autonomous cortisol secretion defined by low-dose dexamethasone suppression testing.

BACKGROUND

Up to 50% of patients with adrenal incidentalomas have mild autonomous cortisol secretion, which may increase their cardiometabolic morbidity, compared with patients with nonfunctional adrenal tumors. Studies evaluating cardiometabolic outcomes of patients with mild autonomous cortisol secretion defined by 1-mg dexamethasone suppression testing (cortisol 1.8-5 μg/dL) have demonstrated mixed results. The aim of this study was to assess the metabolic outcomes of patients with mild autonomous cortisol secretion, defined by the 1-mg dexamethasone suppression testing criterion, compared with patients with nonfunctional adrenal tumors who underwent adrenalectomy.

METHODS

We conducted a single-institution retrospective cohort study comparing adult patients who underwent unilateral adrenalectomy from November 30, 2011, to August 19, 2023, for mild autonomous cortisol secretion (1-mg dexamethasone suppression testing cortisol 1.8-5 μg/dL) or nonfunctional adrenal tumors (1-mg dexamethasone suppression testing cortisol <1.8 μg/dL). Preoperative prevalences and postoperative changes in diabetes mellitus, hypertension, dyslipidemia, and elevated body mass index (≥25) were assessed. Patients were followed from the time of surgery until their last outpatient visit. Multivariable logistic regression was pursued for outcomes that varied between cohorts.

RESULTS

A total of 65 patients (53 mild autonomous cortisol secretion and 12 nonfunctional adrenal tumors) were analyzed. Patients with mild autonomous cortisol secretion were older and more likely to have diabetes mellitus than patients with nonfunctional adrenal tumors (odds ratio: 7.81, 95% confidence interval [0.94, 64.96], P = .04). Patients were followed for a median of 28.1 months [11.1, 55.3 months]. Patients with mild autonomous cortisol secretion were more likely to have postoperative weight improvement (odds ratio: 8.31, [0.97, 71.14], P = .03). After adjusting for clinically relevant variables, the 1-mg dexamethasone suppression testing cortisol was predictive of postoperative weight improvement (odds ratio: 1.88, [1.1, 3.65], P = .04).

CONCLUSION

Weight loss should be considered as a potential benefit of adrenalectomy in patients with mild autonomous cortisol secretion.