Abstract

The objective of the study assess the relationship between bone mineral density (BMD) loss over time and fracture incidence in postmenopausal women. This is a posthoc analysis that includes women from the placebo group of two large randomized controlled trials having assessed the efficacy of a new anti-osteoporotic drug. BMD was assessed every 6 months during 3 years at the lumbar spine, the femoral neck and the total proximal femur. Vertebral fractures were assessed using a semiquantitative method. Hip fractures were based on written documenta- tion. All patients received calcium and vitamin D. In the present study that included 1,775 patients (with complete data at baseline and after 3 years), the logistic regression analysis, adjusted for covariates, showed that 3-year change in lumbar BMD was not statistically associated with the new vertebral fractures after 3 years. However, femoral neck and total proximal femur BMD changes was statistically correlated with the incidence of new vertebral fractures (P < 0.001). When considering change in BMD after the first year of follow-up, a decrease in total proximal femur BMD was statistically associated with an increase in the incidence of new vertebral fractures during the last 2 years of follow-up (P = 0.048). The 3-year change in femoral neck and total proximal BMD was statistically correlated with the incidence of hip and fragility fracture after 3 years (all P < 0.001). In this elderly osteoporotic population receiving calcium and vitamin D, a decrease in hip BMD after 1 or 3 year of follow-up, is associated with an increased risk of fracture incidence. However, spine BMD changes do not influence vertebral fracture incidence.

DOI 10.1007/s10654-009-9381-4

Received 24 February 2009
Accepted 6 August 2009
Published online 29 August 2009