Screening for Osteoporosis in Men: A Systematic Review for an American College of Physicians Guideline

摘要

Background: Screening for low bone mineral density (BMD) by dual-energy x-ray absorptiometry (DXA) is the primary way to identify asymptomatic men who might benefit from osteoporosis treatment. Identifying men at risk for low BMD and fracture can help clinicians determine which men should be tested. nnPurpose: To identify which asymptomatic men should receive DXA BMD testing, this systematic review evaluates 1) risk factors for osteoporotic fracture in men that may be mediated through low BMD and 2) the performance of non-DXA tests in identifying men with low BMD. nnData Sources: Studies identified through the MEDLINE database (1990 to July 2007). nnStudy Selection: Articles that assessed risk factors for osteoporotic fracture in men or evaluated a non-DXA screening test against a gold standard of DXA. nnData Extraction: Researchers performed independent dual abstractions for each article, determined performance characteristics of screening tests, and assessed the quality of included articles. nnData Synthesis: A published meta-analysis of 167 studies evaluating risk factors for low BMD–related fracture in men and women found high-risk factors to be increased age (>70 years), low body weight (body mass index <20 to 25 kg/m2), weight loss (>10%), physical inactivity, prolonged corticosteroid use, and previous osteoporotic fracture. An additional 102 studies assessing 15 other proposed risk factors were reviewed; most had insufficient evidence in men to draw conclusions. Twenty diagnostic study articles were reviewed. At a T-score threshold of −1.0, calcaneal ultrasonography had a sensitivity of 75% and specificity of 66% for identifying DXA-determined osteoporosis (DXA T-score, −2.5). At a risk score threshold of −1, the Osteoporosis Self-Assessment Screening Tool had a sensitivity of 81% and specificity of 68% to identify DXA-determined osteoporosis. nnLimitation: Data on other screening tests, including radiography, and bone geometry variables, were sparse. nnConclusion: Key risk factors for low BMD–mediated fracture include increased age, low body weight, weight loss, physical inactivity, prolonged corticosteroid use, previous osteoporotic fracture, and androgen deprivation therapy. Non-DXA tests either are too insensitive or have insufficient data to reach conclusions. nnOsteoporosis in men is substantially underdiagnosed and undertreated in the United States and worldwide (1). Looker and colleagues (2), evaluating the Third National Health and Nutrition Examination Survey database in 1997, estimated that between 300 000 and 2 million Americans older than age 50 years have osteoporosis and up to 13 million may have low bone mass. A 60-year-old white man has a 25% lifetime risk for an osteoporotic fracture (3), and the consequences of the fracture can be severe. The 1-year mortality rate in men after hip fracture is twice that in women (1). Diagnostic evaluation and treatment of men at high risk for fracture remains low, despite the prevalence of this condition in men (1, 4). nnDual-energy x-ray absorptiometry (DXA) is the current gold standard test for diagnosing osteoporosis in people without a known osteoporotic fracture. It is, however, an imperfect test, identifying less than one half of the people who progress to have an osteoporotic fracture. For example, in the Rotterdam Study (5), the sensitivity of DXA-determined osteoporosis was only 44% and 21% in identifying elderly women and men, respectively, who subsequently had a nonvertebral fracture. Clearly, factors other than low bone mass are important in identifying patients at elevated risk for osteoporotic fracture. An increased risk for falling may explain why some factors are identified as risk factors for osteoporotic fractures independent of bone mineral density (BMD) (for example, tricyclic antidepressants) (6). Although imperfect, a strong and graded relationship exists between DXA-determined BMD and future osteoporotic fracture in women and men (7, 8). The Rotterdam Study (7) reported that the incidence of vertebral and hip fracture approximately doubled for every SD decrease in BMD at the lumbar spine and femoral neck, respectively. Furthermore, pharmacologic treatment of men with low DXA-determined BMD has been shown to decrease the risk for subsequent fractures (9). nnSome organizations have called for universal screening of older men with DXA testing (5, 10). Although these universal DXA screening strategies would probably increase the diagnosis rate of undetected male osteoporosis, such strategies may not be cost-effective in all men. Schousboe and colleagues (11) recently reported that universal screening would probably be cost-effective only in men age 80 years or older, although this result was sensitive to the cost of treatment. In addition, DXA is not portable, requires a special technician, and is not readily available in many locales (5, 10–13), and efforts to find a non-DXA test that is suitable for widespread use have not succeeded to date. nnWe conducted a systematic review of the published literature to identify evidence relevant to screening men for osteoporosis. We focused solely on studies concerning the identification of men with risk factors for fracture that may be mediated through low BMD. Recent reviews have summarized the evidence on non-BMD risk factors, including determining who is at increased risk for falls (14) and treatment of persons at elevated risk (15). Our aims were to determine the risk factors for low BMD–mediated osteoporotic fracture in men that could be used to help select patients for BMD testing and whether non-DXA screening tests could be reliably used to diagnose DXA-defined osteoporosis.