Which of the following statements regarding the epidemiology of osteoporosis and bone fractures is correct?
ExplanationOsteoporosis refers to a chronic condition characterized by decreased bone strength and frequently manifests as vertebral and hip fractures. In the United States, about 8 million women have osteoporosis compared to about 2 million men, for a ratio in women to men of 4 to 1. An additional 48 million individuals are estimated to have osteopenia. The risk of osteoporosis increases with advancing age and rapidly worsens following menopause in women. Most women meet the diagnostic criteria for osteoporosis between the ages of 70 and 80. White women have an increased risk for osteoporosis when compared to African American women. The epidemiology for bone fractures follows the epidemiology for osteoporosis. Fractures of the distal radius (Colles fracture) increase up to age 50 and plateau by age 60, and there is only a modest increase in risk thereafter. This is contrasted with the risk of hip fractures. Incidence rates for hip fractures double every 5 years after the age of 70. This change in fracture pattern is not entirely due to osteoporosis but is also related to the fact that fewer falls in the elderly occur onto an outstretched arm and are more likely to occur directly on the hip. Black women experience hip fractures at approximately half the rate as white women. The mortality rate in the year following a hip fracture is 5%–20%. Vertebral fractures are also common manifestations of osteoporosis. Although most are found incidentally on chest radiograph, severe cases can lead to height loss, pulmonary restriction, and respiratory morbidity.
