2026 Proffered Presentations
S093: POSTOPERATIVE BODY MASS INDEX CHANGE FOLLOWING CURATIVE TRANSSPHENOIDAL SURGERY IN CUSHING'S DISEASE
Jared Chung, BS1; Kathryn Chung, BA1; Georgios Maragkos, MD2; Gregory Hong, MD3; Erica Giraldi, MD3; Michael Catalino, MD2; John Jane Jr, MD4; 1University of Virginia School of Medicine; 2University of Virginia Department of Neurosurgery; 3University of Virginia Department of Endocrinology; 4Carilion Clinic Department of Neurosurgery
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 timepoints were collected: premorbid, preoperative, postoperative at approximately 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 <25 kg/m². Correlation and adjusted regression were used to test whether premorbid BMI predicts later weight loss, which would enable individualized counseling.
Results: Average preoperative BMI was 36.6 kg/m² and most recent BMI was 30.7 kg/m², an average decrease of 5.93 kg/m² (15.4%; 95% CI 4.56–7.30; p=2.28×10?¹²). The time course showed an early decline that later plateaued: the mean change from preoperative BMI was −0.95 kg/m² at about 2 months (p=0.0045), −5.23 kg/m² at about 8 months (p=3.11×10?6), and −6.38 kg/m² at about 14 months (p=2.87×10?7). Modeling across continuous follow up supported a nonlinear trajectory with a significant early component (p=0.0169).
At the most recent visit, 9/65 patients achieved BMI <25 kg/m² (13.8%). Return to within ±5% of premorbid BMI was seen in 13/65 patients (20.0%). Time to these milestones was slow: the median time to BMI <25 was not reached within observed follow up, and the median time to within ±5% of premorbid BMI was approximately 91.5 months. Compared with premorbid BMI, the most recent BMI remained significantly higher by a mean of 2.18 kg/m² (p=0.0266). This demonstrates that premorbid BMI did not predict postoperative weight loss, as the correlation with absolute change was r=0.25 (p=0.065), the correlation with percent change was r=0.18 (p=0.181), and the adjusted regression effect was not significant (p=0.36).
Conclusion: After successful transsphenoidal surgery for Cushing’s disease, most patients lose substantial weight, with the largest improvement in the first postoperative year and a subsequent plateau. Normal BMI is uncommon during typical follow up and return to premorbid BMI is infrequent and slow. Premorbid BMI does not meaningfully predict the degree of postoperative loss. These findings provide concrete expectations for patients and clinicians, highlight achieving ≥5% BMI reduction as a practical early success metric, and support consideration of adjunctive weight-management strategies after surgical remission.
