How hormone exposure affects risk of Parkinsons

March 15, 2009

In postmenopausal women, reproductive factors and hormone therapy may affect the risk of Parkinsons's disease, says recent research.

In postmenopausal women, reproductive factors and hormone therapy use may affect the risk of Parkinson's disease, according to research that will be presented April 25 to May 2 at the annual meeting of the American Academy of Neurology in Seattle.

Rachel Saunders-Pullman, MD, of the Beth Israel Medical Center in New York City, and colleagues assessed data on 83,482 participants in the Observational Study of the Women’s Health Initiative, including 73,973 women who experienced natural menopause and 7,763 who experienced surgical menopause.

The researchers found that the risk of Parkinson’s disease was significantly lower among women experiencing natural menopause who had a fertile lifespan greater than 39 years compared to those with a fertile lifespan less than 33 years (HR, 0.76). They found that the risk was higher among women with at least four pregnancies than in those with three or fewer pregnancies (HR, 1.20). Among women with surgical menopause, they found that those who used hormone therapy had a nearly doubled risk compared to non-users (hazard ratio, 1.92).

"Prior postmenopausal hormone therapy use was not associated with Parkinson's disease among women with natural menopause," the authors write.

More information is available at http://www.aan.com/press/index.cfm?fuseaction=release.view&release=701. Abstracts are available at http://www.aan.com/go/science/abstracts.