Introduction Children with (supra)sellar tumors are at risk for hypothalamic dysfunction (HD). HD may lead to decreased resting energy expenditure (REE) and/or hyperphagia contributing to the development of hypothalamic obesity (HO). Our aim was to assess whether outcomes of REE measurements are associated with clinical severity of HD or radiological posterior hypothalamic damage.

Methods A retrospective study was performed evaluating all children with weight gain or obesity at risk for HD in whom REE measurement was performed between 2014 and 2020. Measured REE (mREE) was compared to predicted REE (pREE) using the Schofield equation. Radiologic hypothalamic damage was scored using Muller grading score plus additional neuroradiological characteristics on MRI. The mREE/pREE quotient was correlated to a clinical score for HD and to radiological hypothalamic damage.
Results Sixty-seven children, with a mean BMI SDS of +2.3 ± 1.0 were included. Of all children, 94% had been diagnosed with a brain tumor (craniopharyngioma, low grade glioma, germ cell tumor, pineoblastoma), while in four other types of brain injuries were present. Children with severe HD had a significant lower mean mREE/pREE quotient (0.65 ± 0.17) compared to children with no HD: 0.89 ± 0.12, mild HD: 0.86 ± 0.19, and moderate HD: 0.88 ± 0.15. Mean mREE/pREE quotient of children with posterior hypothalamic damage on MRI at time of REE measurement (0.74 ± 0.20) was significantly lower compared to children with no damage (0.90 ± 0.12), or anterior damage (0.87 ± 0.13). In the multivariate linear regression, severe clinical HD and tumor progression/recurrence were significant risk factors for mREE/pREE quotient.

Conclusion Low REE correlates to clinical and radiological scores for hypothalamic damage. REE measurements in children surviving a brain tumor 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.