Central Adiposity and Visceral Fat in Long‐Term Survivors of Acute Lymphoblastic Leukemia in Childhood and Adolescence: Exploration of an Underappreciated Risk

INTRODUCTION: Elevated visceral fat is associated with poor cardiovascular health but is not well characterized in survivors of childhood cancer. We examined central adiposity and associated risk factors in a pediatric acute lymphoblastic leukemia (ALL) survivorship cohort. METHODS: Visceral adipose tissue (VAT) mass and estimated waist circumference (WC) were extracted from dual energy x-ray absorptiometry (DXA) scans on 70 survivors of pediatric ALL >10 years from diagnosis. Waist-to-height ratios (WHtRs), a body shape index (ABSI), ABSI z scores, and descriptive statistics were calculated to examine central adiposity. We tested sensitivity/specificity of WHtR at established thresholds for identifying VAT ≥85th percentile (%le). RESULTS: VAT z scores were shifted positively relative to population norms with 25.7% ≥ 85th %le. Mean WHtR was 0.55 ± 0.06 with 82.9% above the "take action" threshold of 0.5. A WHtR ≥0.59 had a sensitivity of 90.2% (95% CI 82.0-98.4) and specificity of 68.4% (95% CI 47.5-89.3) for identifying individuals with VAT ≥85th %le. The mean ABSI z score was 1.88 ± 0.85; higher in women, in high risk ALL, and post-cranial radiation (p = 0.01-0.02). The ABSI z scores for 94.3% of survivors fell in the highest quintile of population values. CONCLUSION: Nearly the entire cohort of long-term survivors of pediatric ALL have an elevated WC relative to height, weight, and population norms, regardless of their body mass index (BMI) or visceral fat. This suggests that a broader screening approach, which considers waist indices, may be better able to detect those at increased cardiometabolic risk. Evaluation and confirmation in a larger prospective cohort is indicated.