Endocrine Abstracts

JOINT1431

Background: Childhood craniopharyngioma (cCP) poses significant risks of hypothalamic damage, leading to severe obesity in up to 75% of survivors. Despite hypothalamus-sparing surgical techniques, hypothalamic obesity remains a prevalent issue. Emerging evidence suggests a link between hypothalamic inflammation (HI) and obesity. In this study, we aimed to investigate the presence of HI before and after cCP surgery using MRI and to study the association between HI and BMI change.

Methods: We conducted a retrospective analysis of two childhood craniopharyngioma cohorts; the Dutch cohort (diagnosed between 2018-2023, n=40), and the German cohort (diagnosed 2019-2023, n=67). Preoperative and postoperative MRI scans were scored, focusing on increased T2 signal intensity (SI) changes on FLAIR, indicative of hypothalamic inflammation(HI). Change of SI in the hypothalamus after surgery was tested and the effect of clinical and radiological variables on post-operative SI was evaluated. In addition, we estimated the correlation between the change in SI and the change in BMI at 3 months postoperatively and quantified the effect of clinical and radiological variables on BMI change at 3 months with a multivariate linear regression model. Lastly, in a subgroup of patients (n=40), post-op signal intensity ratios were compared between patients with or without hypothalamic syndrome (HS) at 6 months.

Results: Both left (P<0.001) and right (P<0.05) hypothalamic SI increased after surgery, indicative of HI. High post-operative SI was associated with increased pre-operative SI, older age, less cystic tumors, and post-operative grade of hypothalamic lesions (Muller score). A positive correlation was found between the change in SI and BMI change at 3 months (r=0.56, 95% CI: 0.29–0.74). SI increase was associated with an increase in BMI Z-score (β=1.02, SE= 0.35) after adjusting for age, tumor composition, and postoperative Muller score. Post-operative SI ratios of patients with hypothalamic syndrome (n=17) were found significantly higher than in those without hypothalamic syndrome (n=23, P<0.01).

Conclusion: Our data suggests that HI may contribute to the BMI increase and development of hypothalamic dysfunction observed after CP surgery. These insights offer a valuable step toward understanding the pathophysiology underlying hypothalamic dysfunction. Prospective studies are needed to confirm our findings.