Estrogen replacement therapy and postural stability in the elderly.

Postural instability and falls in the elderly patient constitute a major health care problem. The etiology is often multifactorial, involving abnormal sensory input (visual, vestibular, and somatosensory), poor central processing, and suboptimal musculoskeletal biomechanics. Estrogen replacement therapy has been shown to prevent Alzheimer's disease and to improve cognitive performance in women with dementia. It was, therefore, postulated that estrogen replacement may improve central processing speed, which would result in improved postural stability. In this prospective, randomized, double-blinded study, 87 elderly female subjects (age > 69) were examined by repeated dynamic platform posturography, to measure the effect of estrogen therapy versus placebo upon postural stability. Results indicate that those receiving estrogen had no significant improvement in postural stability at 2 and 8 months of treatment relative to those receiving placebo. Trail Making B test was used as the psychometric test of central processing speed. There was no significant effect of estrogen on this measure over the 8 months of observations. It is concluded that 8 months of estrogen replacement therapy has no significant effect on central processing speed or postural stability in a healthy older female population.