SUN-449 Randomized Trial of Adrenalectomy Versus Best Medical Practice for Mild Autonomous Cortisol Secretion

Abstract Disclosure: G. Ueland: None. O. Ragnarsson: None. A. Heie: None. A. Kjellbom: None. O. Lindgren: None. A. Muth: None. F. Palazzo: None. P.L. Poulsen: None. L. Rolighed: None. H. Thordarson: None. F. Wernig: None. A. Bergenfelz: None. Objective: To evaluate the impact of adrenalectomy on blood pressure and metabolic parameters in patients with mild autonomous cortisol secretion (MACS). Method: A multicenter prospective randomized clinical trial was conducted, comparing adrenalectomy with conservative management. Blood pressure and metabolic parameters were assessed at baseline and after two years. Results: Forty-three patients with MACS and a single adrenal adenoma were randomized to either adrenalectomy (n=21) or conservative management (n=22). At baseline, 33 patients had hypertension, 13 had type 2 diabetes (T2D), 18 were treated with statins, and 9 patients had established osteoporosis. At two-year follow-up, normalization of cortisol levels post 1mg dexamethasone suppression test (DST) was achieved in 19/21 of adrenalectomy patient compared to 2/22 patients in the conservative group (p<0.01). All patients in the adrenalectomy group had a significant increase in ACTH and DHEA-S. Office systolic blood pressure was significantly reduced in the adrenalectomy group (125 vs 140 mmHg, p=0.03), and a higher proportion of patients in the adrenalectomy group had an improved blood pressure compared with those not operated (14/21 vs. 4/22 patients respectively, p=0.03). The relative risk of improvement of blood pressure in the adrenalectomy group was 7.20 (95% CI 1.53-33.8) compared with the conservative group. Among patients without T2D, the 120-minute glucose level during an oral glucose tolerance test was significantly lower in the adrenalectomy group compared with controls (6.2 vs. 7.3 mmol/L, p=0.04). Conclusion: Adrenalectomy significantly improved blood pressure and glucose metabolism in patients with MACS, suggesting that surgery may reduce cardiovascular risk in patients with MACS and metabolic complications. Presentation: Sunday, July 13, 2025