Skeletal aging understanding the functional and structural basis of osteoporosis

Recent years have seen considerable progress in our understanding of the normal processes by which peak adult bone mass is acquired and maintained, the physical, nutritional, and hormonal factors that regulate bone mass throughout adult life, and the critical role of reproductive hormonal replacement for maintaining bone mass within the early years after menopause. It is now apparent that loss of bone quantity is not sufficient to explain increased fracture risk. Bone fragility depends not only on its material properties, of which mineral content is an important component, but also on its microarchitecture and geometry. Age-related trabecular bone loss is manifest not simply as a global loss of bone, but is characterized by a loss of trabecular connectivity and increased cortical porosity. Appreciation of these issues along with understanding the lifelong process of bone remodeling are central to formulating rational strategies for preventing and treating osteoporosis.