MON-456 Determinants of Hypothalamic Obesity Following Surgical Treatment for Craniopharyngioma in Adults

Abstract

Background: Craniopharyngiomas (CPs) are associated with hypothalamic damage that causes hypothalamic obesity in 30-70% of cases. However, there is an issue of debate for the mechanisms by which CPs cause body weight gain after surgery. In this study, we aimed to reveal the determinants of postoperative weight gain in CP patients compared with non-functioning pituitary adenoma (NFPA) patients. Materials and Methods: We included 48 CP patients aged ≥18 years, who underwent transsphenoidal surgery and measured pre- and postoperative body weight (<120 days after surgery) between 2010 and 2018 in a single tertiary center. One hundred forty-four age- and body mass index (BMI)-matched NFPA patients were recruited. Results: Mean age of diagnosis was 51.3 years and preoperative BMI was 25.0 kg/m2 in overall patients (mean duration of follow-up: 91.2 days). Tumor volume was larger in NFPA patients than in CP patients (119856±18546 mm3 vs. 6285±7795 mm3, P=0.042). CP patients experienced greater postoperative weight gains than NFPA patients (3.0±5.1 kg vs 0.1±3.6 kg, P<0.001). The prevalence of postoperative steroid users was significantly higher in CP patients than in NFPA patients (89.6% vs. 34.0%, P<0.001). The presence of postoperative hormone deficiency did not differ between the two groups (P=0.187). In subgroup analysis with postoperative steroid users, weight gain was significantly greater in CP patients (n=43, 0.96±0.25 kg/month) than in NFPA patients (n=49, 0.26±0.23 kg/month) even after adjusting for steroid replacement dose (P=0.048). Conclusion: CP patients experience greater weight gain than those with NFPA after surgical treatment. Our findings suggest that hypothalamic damage itself as well as steroid replacement therapy may contribute to the postoperative weight gain in CP patients.