Impaired bone strength estimates at the distal tibia and its determinants in adolescents with anorexia nervosa

• Published in: Bone (New York, N.Y.) N.Y.), 2018-01, Vol.106, p.61-68
• Main Authors: Singhal, Vibha, Tulsiani, Shreya, Campoverde, Karen Joanie, Mitchell, Deborah M., Slattery, Meghan, Schorr, Melanie, Miller, Karen K., Bredella, Miriam A., Misra, Madhusmita, Klibanski, Anne
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Adipose Tissue - metabolism; Adolescent; Adolescents; Adult; Anorexia nervosa; Anorexia Nervosa - metabolism; Anorexia Nervosa - physiopathology; Cross-Sectional Studies; Distal tibia; Finite Element Analysis; Humans; Marrow fat; Microarchitecture; Strength estimates; Tibia - metabolism; Tibia - physiology; Weight-Bearing - physiology; Young Adult
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2017.07.009

Altered bone microarchitecture and higher marrow adipose tissue (MAT) may reduce bone strength. High resolution pQCT (HRpQCT) allows assessment of volumetric BMD (vBMD), and size and microarchitecture parameters of bone, while 1H–magnetic resonance spectroscopy (1H–MRS) allows MAT evaluation. We have reported impaired microarchitecture at the non-weight bearing radius in adolescents with anorexia nervosa (AN) and that these changes may precede aBMD deficits. Data are lacking regarding effects of AN on microarchitecture and strength at the weight-bearing tibia in adolescents and young adults, and the impact of changes in microarchitecture and MAT on strength estimates. To compare strength estimates at the distal tibia in adolescents/young adults with AN and controls in relation to vBMD, bone size and microarchitecture, and spine MAT. This was a cross-sectional study of 47 adolescents/young adults with AN and 55 controls 14–24years old that assessed aBMD and body composition using DXA, and distal tibia vBMD, size, microarchitecture and strength estimates using HRpQCT, extended cortical analysis, individual trabecular segmentation, and finite element analysis. Lumbar spine MAT (1H–MRS) was assessed in a subset of 19 AN and 22 controls. Areal BMD Z-scores were lower in AN than controls. At the tibia, AN had greater cortical porosity, lower total and cortical vBMD, cortical area and thickness, trabecular number, and strength estimates than controls. Within AN, strength estimates were positively associated with lean mass, aBMD, vBMD, bone size and microarchitectural parameters. MAT was higher in AN, and associated inversely with strength estimates. Adolescents/young adults with AN have impaired microarchitecture at the weight-bearing tibia and higher spine MAT, associated with reduced bone strength. •Adolescents and young adults with anorexia nervosa have impaired bone strength estimates at the weight-bearing tibia•Adolescents and young adults with anorexia nervosa have higher marrow fat at lumbar vertebrae•Bone strength estimates were positively associated to lean mass, aBMD and microarchitectural parameters (independent of aBMD)•Bone strength estimates at tibia were negatively associated with marrow adipose tissue at lumbar spine