HealthDay News — Postmenopausal bone loss averaged about 10% during 25 years of follow-up in a random sample of women, according to a study published online October 20 in the Journal of Bone and Mineral Research.

Anna Moilanen, from the University of Eastern Finland in Kuopio, and colleagues examined long-term changes in bone mineral density (BMD) after menopause in a random sample of 3222 women from the Kuopio Osteoporosis Risk Factor and Prevention study, of whom 62.1% were postmenopausal at study initiation. These women underwent dual-energy X-ray absorptiometry measurements at the femoral neck every five years from baseline in 1989 and responded to questionnaires assessing risk factors at five-year intervals. The baseline cohort decreased to 686 women during the 25-year follow-up.

The researchers found that the mean 25-year change in BMD was −10.1%. Higher baseline BMD was associated with a higher rate of bone loss; the reductions in the highest and the lowest quartiles of BMD were 11.1 and 7.4%, respectively. Lower baseline body mass index (BMI) and a greater increase in BMI appeared to be protective against bone loss. There were 15.2% more hormone replacement therapy users in the lowest bone loss quartile vs the highest bone loss quartile.

“Postmenopausal bone loss was found to be constant and appeared to be approximately 10 percent over 25 years,” the authors write. “Our findings suggest significantly lower bone loss in postmenopausal women than previously suggested.”

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