RARE-07. Low resting energy expenditure is associated with clinical and radiological hypothalamic damage in children surviving a suprasellar brain tumor

INTRODUCTION: Children with suprasellar brain damage are at risk for hypothalamic dysfunction (HD). HD may lead to decreased resting energy expenditure (REE) contributing to the development of hypothalamic obesity. Decreased REE, however, is not present in all children with hypothalamic damage. Our aim was to assess which children suspect for HD have low REE, and if REE outcome can be associated with clinical severity of HD or with radiological posterior hypothalamic damage. METHODS: A retrospective cohort study was performed evaluating all children diagnosed with brain injury at risk for HD in whom REE measurement was performed. Measured REE (mREE) was compared to predicted REE (pREE) using amongst others the Schofield equation. Low REE was defined as mREE<90% compared to pREE. Radiologic hypothalamic damage was scored using Muller grading score. The mREE/pREE quotient was associated to a clinical score for HD symptoms and to radiological hypothalamic damage. RESULTS: Sixty-seven children suspected for HD (94% brain tumor diagnosis) with a mean BMI SDS of +2.3 ± 1.0 were included. Of these, 45 (67.2%) had mREE <90% compared to the pREE. Children with severe HD symptoms had a significant lower mean mREE/pREE quotient compared to children with no, mild, or moderate HD symptoms. Mean mREE/pREE quotient of children with posterior hypothalamic damage was significantly lower compared to children with no damage or with anterior damage. Tumor progression or tumor recurrence, severe clinical HD, and panhypopituitarism with DI were significant risk factors for reduced REE. CONCLUSION: Not all children suspect for HD have a low REE. Low REE is associated with clinical and radiological scores for hypothalamic damage. REE measurements in childhood brain tumor survivors may be useful to distinguish between those who may benefit from obesity treatment that increases REE from those who would be better helped using other obesity interventions.