Correlation between increased bone mineral density and decreased fracture risk - Bone mineral density as a tool to monitor postmenopausal osteoporosis treatment

Although low bone mineral density (BMD) is predictive of fracture risk in
untreated patients, there is currently debate about the extent to which
the antifracture efficacy of antiosteoporotic agents is related to BMD
changes. The goal of this article is to make an overview of studies dealing with
the association between BMD changes and fracture risk reduction. The percent-
age of the reduction in fracture risk attributable to changes in BMD after an-
tiresorptive treatments (risedronate, alendronate, and raloxifene) varies from
4% to 28%. One study with a bone-forming agent (teriparatide) found that the
proportion of fracture risk reduction attributable to the increase in BMD ranged
from 30% to 41%. With strontium ranelate, the changes in femoral neck and
total hip BMD explained 76% and 74%, respectively, of the reduction in verte-
bral fractures observed during treatment. However, study designs as well as
statistical methods often differ, making the comparison between studies rather
difficult. Our review indicates that the association between BMD changes and
fracture risk is equivocal, but seems to be higher for strontium ranelate than
that reported for its competitors.