CN-17 IMPACT OF AGE AT DIAGNOSIS ON OBESITY IN PEDIATRIC BRAIN TUMOR SURVIVORS

• Published in: Neuro-oncology (Charlottesville, Va.) Va.), 2014-11, Vol.16 (suppl 5), p.v49-v49
• Main Authors: Strobel, K., Simpson, P., Donohoue, P., Firat, S., Jogal, S.
• Format: Article
• Language: English
• ISSN: 1522-8517; 1523-5866
• DOI: 10.1093/neuonc/nou243.17

INTRODUCTION: Obesity is a long-term morbidity for children diagnosed with CNS tumors. Body Mass Index (BMI) normally declines until the age of adiposity rebound (AR), after which it increases. Tumor location, radiation therapy, or surgery near the hypothalamus increases risk of obesity. We hypothesized involvement of the hypothalamus would result in greater BMI, and diagnosis/treatment before AR would lead to the greatest BMI. METHODS: Retrospective cohort of brain tumor survivors diagnosed from 2001-2011 at Children's Hospital of Wisconsin: chart review extracted BMI (recorded as BMI z-score) at diagnosis and two-year follow-up. Children were categorized into six groups, based on age at diagnosis and hypothalamic involvement (HI). Consistent with CDC growth curves, ages were classified as "before AR" (0-41.99 months), "during AR" (42-83.99 months) and "after AR" (84.00 - 120 months old). BMI z-scores were compared using Wilcoxon signed ranks tests. RESULTS: 116 children had two-year follow-up. BMI z-score at diagnosis was similar across groups. Children pre-AR and post-AR with HI had higher BMI z-scores at two-year follow up than at diagnosis (before AR 0.466 to 1.589 p = 0.004 N = 12, after AR 0.519 to 1.268 p = 0.001 N = 18). No group without HI had increased BMI z-score at two-year follow up (before AR 0.663 to 0.518 N = 24, during AR 0.279 to 0.278 N = 18, after AR 0.658 to 0.793 N = 24). The before AR and during AR cohort with HI had a higher BMI z-score at two-year follow up then those without HI (p = 0.004 and 0.015). The after AR cohort did not significantly differ from those without HI at two-year follow up. CONCLUSIONS: Children with CNS tumors with HI have increased BMI compared to those without hypothalamic involvement. Diagnosis before adiposity rebound is associated with a greater BMI than diagnosis at later age. Future studies can help elucidate the endocrine causes of changes.