The effect of estrogen replacement on early Parkinson's disease

To determine the effect of estrogen in postmenopausal women with early PD.

The role of estrogen in PD is highly disputed, with some studies suggesting a prodopaminergic effect and others suggesting an antidopaminergic effect. Owing to controversy and the small sample sizes of prior studies, further investigation is warranted.

A retrospective chart review was carried out from a computerized database of patients at Columbia-Presbyterian, including only women who had symptoms of presumed PD for less than 5 years and who had not yet been on L-dopa at their first visit. Multiple regression was performed to assess the effects of estrogen on disease, measured by total Unified Parkinson's Disease Rating Scale (UPDRS) score, as a function of symptom duration, age at onset, education, smoking, dopamine agonist, and deprenyl use.

Of the women who were not on L-dopa and had PD for less than 5 years at their first visit, 34 were found to have received estrogen at some time and 104 had never received estrogen. Excluding the women who had taken dopamine agonists, analysis yielded a multiple regression coefficient of 0.52 (p < 0.001). Estrogen use was negatively correlated with UPDRS score; age at onset and symptom duration were positively correlated (p < 0.05).

We found a positive association between estrogen use and lower symptom severity in women with early PD not yet taking L-dopa. These results indicate that estrogen therapy should not be avoided and may be beneficial in early PD, at least prior to the initiation of L-dopa.