The clinical evaluation of osteoporosis in women or in men generally focuses on two key issues: (1) Defining the severity of the disease based on bone mineral density (BMD) testing and, in limited circumstances, assessing the level of bone turnover; and (2) Assessing possible secondary causes or contributing factors leading to the development of bone loss. While traditionally considered a disease of women, it is now clear that men also incur substantial bone loss with aging (1, 2) and elderly men have age-specific hip fracture and vertebral fracture rates that are at least half those in women (3). However, while the menopause is the single most important factor contributing to the development of osteoporosis in women, the cause(s) of bone loss in men may be more subtle.
Hence, the clinical evaluation is somewhat different for a woman versus a man presenting with osteoporosis. Moreover, since osteoporosis often has no clinical manifestations until the occurrence of a fracture, the clinician is also faced with the difficult issue of who should be "screened" for the disease - a contentious issue in today's healthcare environment. The following discussion attempts to provide a working approach to the diagnostic evaluation of the patient (female and male) with osteoporosis, including some considerations on which patients should be targeted for evaluation for the disease so that preventive therapy can be instituted prior to the development of overt fractures.
There is little doubt that the patient presenting with an osteoporotic fracture (distal forearm or "Colles", vertebral, or hip) warrants a thorough evaluation and subsequent treatment, although it is surprising how few of even these patients are offered this in the community. The more difficult issue is deciding which asymptomatic patients should undergo BMD testing and further evaluation based on the results of the bone mass measurements. If the cost of testing were negligible, then clearly a broad "screening: strategy would be appropriate and cost-effective. However, depending on the technique used and the center, the cost of obtaining a bone density can be substantial. Thus, general screening is not possible, or perhaps even justified. As such, the National Osteoporosis Foundation (NOF) has performed a detailed cost-effectiveness analysis and attempted to identify women who should be offered BMD testing, based on the presence of risk factors for osteoporosis (Table 1).
Table 1. Risk factors for osteoporotic fracture in postmenopausal women, as identified by the NOF guidelines for the prevention and treatment of osteoporosis (4).
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Nonmodifiable
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Potentially modifiable
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The four items in boldface type are key factors in determining risk of hip fracture independent of BMD. |
Based on these risk factors, the NOF recommended offering BMD testing to the following women:
All postmenopausal women under age 65 who have one or more additional risk factors for osteoporosis (besides menopause).
All women aged 65 and older regardless of additional risk factors.
Postmenopausal women who present with fractures (to confirm diagnosis and determine disease severity).
Women who are considering therapy for osteoporosis, if BMD testing would facilitate the decision.
Women who have been on hormone replacement therapy for prolonged periods.
This report, extensive as it was, focused on postmenopausal women, who are at greatest risk for the development of osteoporosis. Table 2, however, lists additional risk factors, and in particular secondary diseases, that clearly predispose to the development of osteoporosis in all individuals (including premenopausal women and men). The presence of one or more of these factors or disorders should also prompt the clinician to consider evaluating BMD and the risk of osteoporotic fractures.
Table 2. Additional risk factors for osteoporosis in women and in men. Adapted from (5), with permission.
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In summary, while there is no doubt that the patient presenting with osteoporotic fractures warrants a thorough evaluation, more difficult is the decision to measure BMD in the asymptomatic individual. For postmenopausal women, the recommendations provided by the NOF provide a useful guidepost. In the case of premenopausal women or men, in the absence of any clear recommendations, one has to use clinical judgement, including an awareness of the potential factors predisposing to bone loss in these individuals, as listed in Table 2.