title: Exposure to estrogen and women's risk for Parkinson's disease: a prospective cohort study in Denmark.
abstract: BACKGROUND
  Studies have suggested that estrogen is protective against Parkinson's disease; however, the results have been inconsistent.
  
  
  METHODS
  Our cohort comprised 27,466 women from the prospective Diet, Cancer and Health study. At inclusion, all the cohort members filled in questionnaires on diet and lifestyle, including reproductive factors, use of hormone products, and smoking habits. The cohort was followed up for Parkinson's disease in the Danish Hospital Register, and risks associated with indicators of exposure to estrogen were estimated in a Cox proportional hazards model.
  
  
  RESULTS
  No significant association was found between reproductive factors and risk for Parkinson's disease. Use of oral contraceptives was associated with a nonsignificantly increased risk (hazard ratio, 1.30; 95% confidence interval, 0.81-2.09), as was use of hormone replacement therapy (1.41; 0.90-2.21).
  
  
  CONCLUSIONS
  Our data do not support the hypothesis of a protective effect of estrogen on the risk for Parkinson's disease in women.
authors: Danish Cancer Society Research Center, Strandboulevarden 49, DK-2100 Copenhagen, Denmark. rugbjerg@cancer.dk
authors: Kathrine
authors: K
authors: Rugbjerg
authors: Jane
authors: J
authors: Christensen
authors: Anne
authors: A
authors: Tjønneland
authors: Jørgen H
authors: JH
authors: Olsen
mesh_terms: D015331:Cohort Studies; D003278:Contraceptives, Oral, Hormonal / Q000627:therapeutic use; D003718:Denmark; D004967:Estrogens / Q000627:therapeutic use*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012307:Risk Factors
chemical_list: D003278:Contraceptives, Oral, Hormonal; D004967:Estrogens