Uses and limitations of bone mineral density measurements in the management of osteoporosis.
BACKGROUND
Bone mineral density (BMD) is used to diagnose osteoporosis, and often to measure efficacy in osteoporosis treatment trials; however, there is a poor correlation between lumbar spine BMD increases and vertebral fracture risk reduction in patients receiving treatment for osteoporosis.


OBJECTIVE
The purpose of this article is to review the uses and limitations of BMD measurements and the relationship between BMD and bone strength. DATA SOURCE/STUDY SELECTION: A MEDLINE literature search was conducted with the terms bone mineral density , fracture , osteoporosis , and bone strength as well as the generic names of osteoporosis therapies (alendronate, risedronate, raloxifene, teriparatide, and calcitonin). Search results were limited to English language journals and articles published within the last 20 years. Published abstracts from scientific meetings were also reviewed.


CONCLUSIONS
BMD measurement remains the most useful diagnostic tool for identifying patients with osteoporosis. Although they are helpful in guiding decisions to initiate osteoporosis treatment, subsequent changes in BMD provide an imperfect indicator of treatment efficacy. Analyses of clinical trials show an inconsistent relationship between increased spinal BMD and a decreased risk of vertebral fracture. Increased BMD accounts for less than 25% of the overall reduction in fracture risk in most instances. Consequently, fracture risk reduction itself remains the most clinically relevant therapeutic outcome of osteoporosis therapy.
Small
Ralph E
RE
Virginia Commonwealth University, Richmond, Virginia, USA. ralphsmall@rcn.com
D015502:Absorptiometry, Photon / Q000706:statistics & numerical data*; D002113:Calcification, Physiologic; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000453:epidemiology*; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000517:prevention & control