Postoperative Body Mass Index Change Following Curative Transsphenoidal Surgery in Cushing's Disease

Introduction: Cushing’s disease causes substantial weight gain due to chronic hypercortisolism, yet postoperative weight trajectories after remission remain variable. Transsphenoidal surgery (TSS) is the standard curative approach, but the expected trajectory and likelihood of BMI improvement after successful surgery are uncertain. Prior studies are small and heterogeneous, so contemporary cohort data are needed to set realistic expectations for patients and clinicians. Objective: To characterize postoperative BMI change after successful TSS for Cushing’s disease. Methods: This was a single-institution longitudinal cohort of 65 patients underwent successful transsphenoidal surgery from 2017 to 2023, defined as biochemical remission at latest follow up from surgery alone without recurrence. For each patient, seven BMI time points were collected: premorbid, preoperative, postoperative at ~2 months, 8 months, 14 months, and 1 year, and the most recent available BMI. Absolute and percent change from preoperative BMI to most recent was analyzed to describe the postoperative trajectory of BMI change. Cumulative incidence curves were generated for three milestones, reflecting goals of care: achieving ≥5% BMI reduction, returning to within ±5% of premorbid BMI, and reaching normal BMI