ODP639 The Occurrence and Predictors of Postoperative Adrenal Insufficiency for Patients With Subclinical Cushing's Syndrome

OBJECTIVE: To identify the occurrence and predictive factors of postoperative adrenal insufficiency in patients with subclinical Cushing's syndrome (SCS), and try to provide evidence for decision-making in SCS management. METHODS: The present retrospective analysis included 77 patients who underwent unilateral laparoscopic adrenalectomy for SCS between December 2011 and April 2021. Among them, 59 patients with complete follow-up data were included. We compared clinical characteristics of patients with and without postoperative adrenal insufficiency. The logistic regression model was used to find the potential risk factors in predicting the occurrence of postoperative adrenal insufficiency. The receiver operating characteristic (ROC) curve was used to evaluate the predictive values. RESULTS: We included 59 patients, of whom the incidence of postoperative adrenal insufficiency is 42.37%. The circadian rhythms of adrenocorticotropic hormone (ACTH) and cortisol disappeared in both two groups. Compared patients without postoperative adrenal insufficiency, patients with postoperative adrenal insufficiency were characterized by suppressed plasma ACTH level [1.11(1.11, 1.83) pmol/L vs 2.56(1.16, 4.63) pmol/L], elevated midnight cortisol level [268. 00(164. 00, 347.50) nmol/L vs 181.50(156.32, 227. 00) nmol/L] and increased cortisol level after 1 mg overnight dexamethasone suppression test (DST) [281. 00(241. 00, 396.64) nmol/L vs 172.50(144. 05, 215.25) nmol/L] (all P < 0. 05). Multivariate logistic regression analysis showed that the serum cortisol after a 1 mg-DST was the only independent predictive factor for the occurrence of postoperative adrenal insufficiency. The ROC curve showed that the best cut-off value of the serum cortisol after a 1 mg-DST was 233 nmol/L, with a sensitivity of 80. 00% and a specificity of 82.35%. The combination of the serum cortisol after a 1 mg-DST, plasma ACTH and midnight cortisol had the highest predictive accuracy (83. 05%). CONCLUSION: Patients who underwent unilateral laparoscopic adrenalectomy for SCS had a risk of postoperative adrenal insufficiency. The pre-surgical assessment of the serum cortisol after a 1 mg-DST plus elevated midnight cortisol and suppressed plasma ACTH had predictive value for the occurrence of postoperative adrenal insufficiency. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Monday, June 13, 2022 1:00 p.m. - 1:05 p.m.