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.