Bone marrow changes in adolescent girls with anorexia nervosa

Abstract

Early osteoporosis is common among adolescent girls with anorexia nervosa (AN) and may result from premature conversion of red (RM) to yellow bone marrow. We performed right knee magnetic resonance imaging (MRI) on a 1.0 T extremity scanner in 20 patients and 20 healthy controls, aged 16.2 ± 1.6 years (mean ± SD). Coronal T1-weighted (T1W) images and T1 maps were generated from T1 relaxometry images. Blinded radiologists visually assessed RM in the distal femoral and proximal tibial metaphyses in T1W images using a scale of signal intensity from 0 (homogeneous hyperintensity, no RM) to 4 (all dark, complete RM). Subjects with AN exhibited nearly twofold lower metaphyseal RM scores in both the femur (0.64 versus 1.22, p = .03) and tibia (0.54 versus 0.96, p = .08). In relaxometric measurements of four selected regions (femur and tibia amd epiphysis and metaphysis), subjects with AN showed higher mean epiphyseal but lower metaphyseal T1. The net AN-control difference between epiphysis and metaphysis was 70 ms in the femur (+31 versus −35 ms, p = .02) and of smaller magnitude in the tibia. In relaxometry data from the full width of the femur adjacent to the growth plate, AN subjects showed mean T1 consistently lower than in controls by 30 to 50 ms in virtually every part of the sampling region. These findings suggest that adolescents with AN exhibit premature conversion of hematopoietic to fat cells in the marrow of the peripheral skeleton potentially owing to adipocyte over osteoblast differentiation in the mesenchymal stem cell pool. © 2010 American Society for Bone and Mineral Research

Effects of risedronate on bone marrow adipocytes in postmenopausal women

“…However, no relationship between serum parameters and changes in marrow adiposity is expected. This is due to the current understanding that, in contrast with other types of fat, the role and function of marrow fat are independent of general body mass or changes in levels of serum lipids [33,34]. In fact, in their study, Syed et al [9] found that changes in serum leptin in either group did not correlate with changes in bone or adipocyte parameters.…”

The Role of Bone Marrow and Visceral Fat on Bone Metabolism

“…It has been suggested that the role of BMF is distinct from that of visceral and subcutaneous adiposity. This hypothesis is supported by studies in anorexia nervosa (AN) patients, in which extreme low body fat mass (including VAT and SAT) is present [50]. Not only do AN patients have a high prevalence of osteoporosis, but there is also a high vertebral BMF content.…”

Bone Remodeling and Energy Metabolism: New Perspectives

“…Eckuland et al described unequivocal augmenttation of marrow fat in a group of adolescents with anorexia nervosa in comparison to a control group (99). In another study, the investigation of the hormonal/ metabolic profile of patients with anorexia nervosa showed normal insulin sensitivity and increased levels of serum adiponectin in relation to normal weight control women (100).…”