Elevated IGF‐1 concentrations in children with low grade glioma: A descriptive analysis in a retrospective national cohort

Children with low grade glioma (LGG) may present with, or develop, elevated concentrations of insulin‐like growth factor 1 (IGF‐1). The prevalence, pathophysiology, or its possible clinical effects are poorly understood. Our aim was to evaluate the prevalence of such elevated IGF‐1 concentrations and to describe its association with linear growth, body mass index (BMI), pituitary outcome, and tumor behavior in a large retrospective national cohort. From a nationwide retrospective cohort of pediatric brain tumor survivors diagnosed between 2002 and 2012, tumor, treatment, endocrine, and auxological data of children with LGG were collected (n = 358). Prevalence and risk factors for elevated IGF‐1 concentrations, as well as the association between having elevated IGF‐1 concentrations and receiving tumor treatment, were explored. IGF‐1 concentrations had only been measured in 45.5% of cases (n = 163/358). In 18.4% of 163 children with available IGF‐1 measurements, IGF‐1 concentrations were found elevated. No association was described between having an elevated IGF‐1 concentration and tumor behavior or height SDS at last moment of follow‐up. Multivariate logistic regression identified posterior pituitary disorder (OR 6.14 95% CI: 2.21–17.09) and BMI SDS at follow‐up (OR 1.56 95% CI: 1.09–2.20) to be significantly associated with elevated IGF‐1 concentrations. In this retrospective cohort of children with LGG, IGF‐1 was found elevated in 18.4% of children with available IGF‐1 measurements. Elevated IGF‐1 seems to be related to hypothalamic dysfunction worsening over time. Larger prospective cohort studies are needed. Elevated IGF‐1 concentration (> +2 SDS) was found in 18.4% of childhood low grade glioma and seems to be related to hypothalamic dysfunction (BMI and posterior pituitary disorder) worsening over time.