Aging and bone mineral density

"Change in bone mineral density as a function of age in women and men and association with the use of antiresorptive agents"

Older women and men experience increasing rates of hip fracture because of the age-related acceleration in bone loss. David Goltzman and colleagues studied a large cohort of Canadians and found that antiresorptive medication attenuates this loss.

The authors found that even among women aged 50-54, the range within which the greatest bone loss was noted, the rate was only 1.3% per year. This finding is consistent with rates of loss reported among women in other longitudinal studies. The authors also note that a loss of 1.3% is within the margin of error of most bone densitometry machines.

"The extent of the bone loss that we observed suggests that repeat measurements of bone density could be delayed to intervals of up to 5 years in the absence of other risk factors," conclude the authors.

In a related commentary, Dr. Mark Cooper, Department of Endocrinology, Division of Medical Sciences, University of Birmingham, United Kingdom (m.s.cooper@bham.ac.uk), highlights the 2-phased nature of bone loss, first around menopause and then after the age of 70. He also stresses that the change in bones over time is complex and that bone density is only one of many factors that can influence an individual's risk for fracture.