Pathophysiology of Ostoeporosis

Bone is a dynamic tissue. Throughout a person's life span, nw bone is formed by osteoblastic activity, whereas old bone is resorbed activity; this process is known as bone modeling. BMD determines bone strength and peaks between 30 and 35 years of age. After the peak years, bone resoption activity exceeds bone-building activity, and bone density decrease. Trabecular, or cancellous (spongy), bone is los first, followed by loss of cortical cortical (compact) bone.
BMD decreses rapidly in postmenospausal women as serus estrogen level diminish. Approximatly 40% to 45% of a woman's bone mass is lost during herl life span. It is estimated that 50% of all women older than 65 years of age have symptomatic osteoporosis.
More than half of all Caucasion women have at least one osteoporotic fracture during their lifetime. Men also develop osteoporosis and resulting frctures. Studies have shown that although men are less likely than women to experience a fracture, the lifetime ris of fracture is 13% to 25% (Bilezikian, 1990)