RCTs of ERT and Parkinson’s disease.
|Study (reference)||Hormone treatment used||Sample Size||Outcome measure||Overall findings|
|Blanchet ||High-dose transdermal E2. Cross-over design with 2 weeks on E2, 2 week washout, and 2 weeks on placebo||8||Therapeutic threshold for levodopa.||All but one participant had levodopa-induced dyskinesia at start of study. After 10 days of E2 treatment a significant reduction was observed in the anti-parkinsonian threshold dose of intravenous levodopa without significantly worsening dyskinesias.|
|Strijks et al. ||17β-estradiol (E2) versus placebo for 8 weeks||12||Motor score from the Unified Parkinson’s Disease Rating Scale (UPDRS); patient report of subjective changes.||No differences in outcome measures between E2 and placebo.|
|Tsang et al. ||CEE versus placebo for 8 weeks||40||UPDRS, timed tapping score, Hamilton Depression Scale, patient self-report.||“On” and “off” times, and motor score on the UPDRS improved with estrogen.|
|The Parkinson Study Group Poetry I Investigators ||CEE versus Placebo for 8 weeks||23||Primary outcome was ability to complete the trial. Other outcome measures included adverse events, UPDRS, “on” time, dyskinesia ratings, and neuropsychological functioning.||The estrogen group showed a trend for improvement on the total and motor UPDRS scores.|