Body Composition Assessment and Correlation to Metabolic Profile in Survivors of Childhood Brain Tumors

INTRODUCTION: Survivors of childhood brain tumors (CBT) are at increased risk for metabolic syndrome, contributing to long-term cardiometabolic morbidity. BMI may underestimate risk by failing to capture altered body composition in this population. More precise tools such as air displacement plethysmography (ADP) may improve early risk detection. This study aimed to identify ADP-derived markers of adiposity and characterize early metabolic abnormalities at the end of cancer therapy. METHODS: This was a prospective, single-visit study enrolling pediatric survivors of high-grade CBT aged 2 to 21 years, off therapy for <5 years. Data included anthropometric measurements, metabolic markers (glucose, insulin, lipids, adiponectin, leptin, IL-6), and body composition (fat mass, fat-free mass, percent fat, measured by ADP). Descriptive statistics were used to summarize demographics and clinical characteristics, and categorical variables were presented as counts and percentages. Pearson correlation coefficients were calculated for log adiponectin versus percent body fat and BMI z-score. RESULTS: Thirty survivors of CBT (n=30; age: 6 to 23 y) were evaluated a median of 0.3 years after treatment. Over half were normal weight (53%), and 47% were overweight or obese; 20% had hypertension and 23% had elevated waist circumference. Body composition (n=29) showed high adiposity, with a mean fat mass of 33% and 59% having elevated fat percentage. Metabolic assessment demonstrated early cardiometabolic dysfunction: insulin resistance and significant insulin resistance by HOMA-IR were seen in 50% and 33%, respectively, and lipid abnormalities and the metabolic syndrome were seen in 27% and 15%, respectively. Higher adiposity was associated with worse metabolic health, with greater fat mass percentage in insulin-resistant patients (P<0.01) and higher BMI z-score (P=0.02). Adiponectin was inversely correlated with fat mass% (r=-0.72), but not with BMI z-score. CONCLUSION: Childhood brain tumor survivors demonstrated a high prevalence of metabolic abnormalities and excess adiposity shortly after therapy completion. BMI underestimated abnormal adiposity compared with ADP-derived body composition assessment, supporting the need for comprehensive metabolic screening and early intervention during survivorship.