Relationship between change in femoral neck bone mineral density and hip fracture incidence during treatment with strontium ranelate.

OBJECTIVE: Strontium ranelate (SR) increases bone mineral density (BMD) in postmenopausal osteoporotic women and reduces vertebral and non-vertebral fracture incidence. Hip fracture reduction has also been observed during 3-year treatment with SR in osteoporotic women at high risk of hip fracture. The objective of this study is to analyse the association between BMD changes and hip fracture incidence during treatment with SR.

MATERIAL AND METHODS: In this post-hoc analysis, 465 women aged over 74 years with low BMD at the femoral neck (T-score < or = -2.4 according to NHANES normative values) were selected from the population of a recently published study (the Treatment of Peripheral Osteoporosis Study - TROPOS). BMD was assessed at the femoral neck at baseline and after a follow-up of 3 years. Hip fractures were reported by study investigators.

RESULTS: After adjusting for age, body mass index, femoral neck BMD at baseline and number of prevalent vertebral fractures, we found that for each 1% increase in femoral neck BMD observed after 3 years, the risk to experience a hip fracture after 3 years decreased by 7% (95% CI: 1-14%) (p = 0.04). In patients experiencing a hip fracture over 3 years of treatment with SR, femoral neck BMD increased by (mean [SE]) 3.41 (1.02)% compared to 7.23 (0.81)% in patients without hip fracture (p = 0.02).

CONCLUSION: In this post-hoc analysis of women undergoing 3 years of SR treatment, an increase in femoral neck BMD is associated with a decrease in hip fracture incidence.