Hormone therapy and postural balance in elderly women.

OBJECTIVE

Most fractures occur in elderly individuals without osteoporosis, and more than 90% of all hip fractures are associated with a fall. It is unclear whether hormone therapy (HT) can improve postural balance when initiated in elderly women and the effect of endogenous estradiol (E2) levels.

DESIGN

Forty healthy women (33 assessable), age 60 years or older, were recruited through advertising in the local media. They were randomly and blindly assigned to receive either estradiol patches (50 microg/24 h) combined with oral medroxyprogesterone acetate (2.5 mg/d) or placebo for 6 months. Postural balance was assessed as sway velocity using a force platform.

RESULTS

Low serum E2 levels were associated with greater impairment of sway velocity during the study in the placebo group. After 6 months sway velocity had improved (decreased) in the HT group by 4.3% from baseline and increased in the placebo group by 6.2%. The difference was not significant (1.30 cm/s, 95% CI: -3.0 to 0.4; P = 0.13). However, among women with low serum E2 levels at baseline (less than the median, 35 pmol/L), sway velocity improved in the HT group and deteriorated in the placebo group with a difference of 23% (2.9 cm/s, 95% CI: 0.6-5.1; P = 0.013). There were similar results after adjustment for baseline sway velocity (P = 0.003) and in the intention-to-treat analysis (P = 0.023). There was also a significant interaction between the study group and baseline serum E2 levels with regard to changes in sway velocity (P = 0.014).

CONCLUSIONS

In elderly women low endogenous serum E2 levels were associated with greater impairment of postural balance function during the study, whereas HT, as compared with placebo, improved postural balance in women with low serum E2 levels.