Prospective study of radial bone mineral density in a geographically defined population of postmenopausal Caucasian women.

The radial bone mineral density (BMD) mass of 324 Caucasian women, aged 55-80 years, from geographically defined areas was evaluated in 1983 using single photon absorptiometry; 271 of these women (86%) were reexamined 5 years later in 1988. More than 65% of women lost radial BMD in excess of 1%/year in the 5-year follow-up. Thirty percent of women lost at least 2%/year. Baseline radial BMD measures taken in 1983 were highly predictive of the 1988 radial BMD values, explaining approximately 82% of the variability. The rate of bone change, expressed as percent change or 5-year difference (g/cm2), was not associated with baseline radial BMD value. Rate of change was not strongly associated with chronologic age or years since menopause, even when data were restricted to those women who reported no previous use of perimenopausal estrogen or thiazide medication. We conclude that BMD loss in a general population may be more substantial than previously believed.