Bone loss and wrist fractures after withdrawal of hormone therapy: The 15-year follow-up of the OSTPRE cohort.

CONTEXT: Long-term bone mineral density (BMD) or fracture incidence changes after withdrawal of postmenopausal hormone therapy (HT) are not well known.

OBJECTIVE

To study long-term postmenopausal bone loss and incidence of wrist fracture in respect to duration and withdrawal of self-reported HT.

DESIGN/

SETTING

A 15-year follow-up of the population-based prospective OSTPRE cohort in Kuopio, Finland.

PARTICIPANTS

Women (mean baseline age 53.4 years, range 48.1-59.6) were divided into four groups based on duration of HT: (1) never users (non-HT); (2) those who had used HT only throughout the 1st 5-year period (HT5); (3) throughout the first 10-years (HT10); (4) those who used HT throughout the entire 15-year follow-up (HT15).

OUTCOME MEASURES: Femoral (n=857) and spinal (n=599) BMD measurements with dual X-ray absorptiometry (DXA) were carried out at 5-year intervals in 1989-2004. Wrist fracture incidence in 1989-2004 was studied in a population of 5119 women.

RESULTS

The adjusted spinal BMD (L2-L4) changes by HT use during the entire 15-year follow-up were -4.8% for non-HT (p<0.0001), -4.2% for HT5 (p=0.003), +0.02% for HT10 (p>0.05) and +3.2% for HT15 (p<0.0001) groups. The respective femoral bone losses were -8.6% for non-HT (p<0.0001), -7.9% for HT5 (p<0.0001), -2.5% for HT10 (p=0.010) and -0.2% for HT15 (p>0.05) groups. Comparing to non-HT group the risk of wrist fracture was reduced by 33% (p=0.045) in HT10 group and by 63% (p<0.0001) in HT15 group during the 15-year follow-up.

CONCLUSION

Long-term HT-use protects from bone loss. Thus, it reduces the incidence of osteopenia, osteoporosis and wrist fractures. Still, HT-use of less than 5 years did not have long-term bone protective effects, but a larger sample size is needed to confirm this result.