Histologically, there is a reduction in cortical thickness and in the number and size of trabeculae of cancellous bone, with normal width of the osteoid seams. Trabecular bone loss predominates in typical postmenopausal osteoporosis. Peak bone mass in men and women occurs by the middle of the third decade of life and plateaus for about 10 years, during which turnover of bone is constant, with bone formation approximately equaling bone resorption. The major clinical manifestations of osteoporosis are bone fractures, which cause chronic pain. However, not everyone with low bone mass will experience fracture.
Falls add additional risk.
Many elderly persons are at risk for falls because of poor coordination, poor vision, muscle weakness, confusion, and use of hypnotics or other medications that alter the sensorium. The use of hip pads by elderly patients can reduce the incidence of hip fracture despite continued falls. Increasing physical activity may increase bone mineral density and lead to increased stability and muscle strength. Levels of these cytokines rise with the loss of estrogen and enhance bone resorption through increased recruitment, differentiation, and activation of osteoclasts. Although calcitonin levels are decreased in women compared with men, calcitonin deficiency does not appear to be important in age-related osteoporosis.