[Bone loss during aging or how one becomes osteoporotic?]

There is currently a better understanding of bony loss secondary to ageing. It involves cancellous bone as well as cortical bone. Since remodelling of cancellous bone is approximately 7 times higher than that of cortical bone, the bony loss will always be more marked in cancellous bone, especially in vertebral bodies which are essentially made of cancellous bone. In women, the total bony loss secondary to ageing is about 50 p. cent for cancellous bone and 35 p. cent for cortical bone; it is approximately 35 and 20 p. cent in men. Increased bony loss is observed in women during the 10 years following menopause. For instance, the trabecular bony loss, especially in the vertebrae, may reach 1 to 2 p. cent per year, even reaching 12 p. cent during the 2 years following ovariectomy.