Cohen et al. evaluated bone microarchitecture and remodeling in healthy premenopausal women of varying weights, asking whether the effects of obesity on bone are mediated by increased bone resorption or decreased bone formation.1
Bone microarchitecture, stiffness and remodeling, and marrow fat were assessed in labeled transiliac bone biopsies and compared to -trunk fat and body mass index (BMI) measured by dual-energy X-ray absorptiometry, and visceral fat measured by computed tomography.
Trunk fat, visceral fat and BMI were all directly associated. Bone quality, bone stiffness, trabecular bone volume, cortical porosity and the level of bone formation measured in premenopausal women with greater central adiposity were all inferior when compared with matched controls with the lowest level of trunk fat. For example, the bone formation rate measured in women of the lowest tertile of trunk fat (0.011±0.008 mm2/mm·year) was 64% higher than the bone formation rate seen in women in the highest tertile of trunk fat (0.004±0.002 mm2/mm·year; P=0.006).
Editor's comment: The conventional view that obesity is beneficial for bone strength is again challenged by studies that link visceral obesity to low bone mass and fractures. This is likely to have significant implications for fracture risk as these women age.
References
- Cohen A, Dempster DW, Recker RR, Lappe JM, Zhou H, Zwahlen A et al. Abdominal fat is associated with lower bone formation and inferior bone quality in healthy premenopausal women: a transiliac bone biopsy study. J Clin Endocrinol Metab 2013;98:2562–2572. [DOI] [PMC free article] [PubMed] [Google Scholar]
