SUN-464 Post 1 mg Dexamethasone Suppression Test Cortisol Elevations Predict Significant Impairment in Postbariatric Surgery Glucose Metabolism: A Retrospective Longitudinal Cohort Study

Abstract Disclosure: F. De Domenico: None. V. Zanghi Buffi: None. O. Lanza: None. S. Manfrini: None. D. Tuccinardi: None. Introduction: The function of the hypothalamic-pituitary-adrenal axis may influence bariatric surgery outcomes. This retrospective longitudinal cohort study investigated the correlation between pre-operative plasma cortisol concentration after a 1mg dexamethasone suppression test (DST) and post-bariatric surgery metabolic parameters in obese patients. Methods: We enrolled 67 prediabetic patients (72% female, mean age 48±10 years) with grade III obesity or complicated grade II obesity showing clinical signs of hypercortisolism. Patients underwent bariatric surgery (72% sleeve gastrectomy, 16% Roux-en-Y gastric bypass, 8% other procedures) and had a pre-operative DST. Metabolic parameters were assessed at baseline and 3-, 6-, 12-, and 24-months post-surgery. Linear regression analyses evaluated associations between pre-operative cortisol levels and changes in metabolic parameters. Results: Pre-operative cortisol levels after DST showed complex associations with post-bariatric surgery metabolic outcomes. For every 1 mcg/dl increase in baseline cortisol, there was a 1.479 mg/dl smaller reduction in glucose levels at 12 months (p=0.037, R²=0.105), suggesting resistance to metabolic benefits. This relationship weakened when adjusted for age and sex. BMI changes showed no significant associations during the first year but trended toward greater reduction with higher cortisol at 24 months. Lipid profiles demonstrated significant improvements: total cholesterol, LDL, and triglycerides showed negative associations at 6 and 12 months. HDL displayed a unique biphasic pattern with positive trends at 3 months and a significant positive association at 24 months. Patients with normal cortisol suppression (cortisol < 1.8 mcg/dl) showed greater reductions in glucose at 12 months (p=0.048) and triglycerides at 6 months (p=0.014). Conclusion: The study reveals a complex interplay between cortisol and metabolic outcomes following bariatric surgery. Pre-operative cortisol levels may serve as valuable predictors of metabolic responses, guiding personalized post-operative monitoring strategies. The observed differences in glucose and triglyceride reductions between groups with normal and abnormal cortisol suppression underscore the importance of pre-operative cortisol assessment. These findings highlight the need for further research to fully understand the role of hypothalamic-pituitary-adrenal axis function in bariatric surgery outcomes and its potential implications for tailored patient management. Presentation: Sunday, July 13, 2025