Adolescent girls with anorexia nervosa have impaired cortical and trabecular microarchitecture and lower estimated bone strength at the distal radius

Abstract

Context: Adolescents with anorexia nervosa (AN) have low areal bone mineral density (aBMD) at both corticalandtrabecular sites, and recent datashowimpaired trabecular microarchitecture independent of aBMD. However, data are lacking regarding both cortical microarchitecture and bone strength assessment by finite element analysis (FEA) in adolescents with AN. Because microarchitectural abnormalities and FEA may predict fracture risk independent of aBMD, these data are important to obtain. Objective: Our objective was to compare both cortical and trabecular bone microarchitecture and FEA estimates of bone strength in adolescent girls with AN vs normal-weight controls. Design, Setting, and Subjects: We conducted a cross-sectional study at a clinical research center that included 44 adolescent girls (21 with AN and 23 normal-weight controls) 14 to 22 years old. Main Outcome Measures: We evaluated 1) aBMD (dual-energy x-ray absorptiometry) at the distal radius, lumbar spine, and hip, 2) cortical and trabecular microarchitecture at the ultradistal radius (high-resolution peripheral quantitative computed tomography), and 3) FEA-derived estimates of failure load at the ultradistal radius. Results: aBMD was lower in girls with AN vs controls at the lumbar spine and hip but not at the distal radius. Girls with AN had lower total (P