title: [A case-control study of endogenous estrogen and risk of Alzheimer's disease].
abstract: OBJECTIVE
  To investigate the risk of Alzheimer's disease (AD) associated with endogenous estrogen.
  
  
  METHODS
  A population based, m: n matched case-control study was conducted, including 115 female AD patients identified from sample population aged 55 years or older as cases and 1,041 non-cognitive impairment individuals from same population matched for age and sex as controls.
  
  
  RESULTS
  Age at natural menopause had significant effect on AD using multivariate analysis. The odds ratio (OR) for AD was 0.672 for individuals whose age at natural menopause were between 47 to 50 years old, compared with individuals whose age at menopause were less than 47 years old. The OR was 0.452 for individuals whose age at menopause were more than 50 years old comparing with individuals whose age at menopause were less than 47 years old (P = 0.0207). The OR for AD increased parallel to the increase of age at menarche (adjusted OR = 1.160 for each increased year, P = 0.0342).
  
  
  CONCLUSIONS
  The decrease of endogenous level in postmenopausal women might serve an etiological factor for AD.
authors.affiliation: Department of Neurology, Peiking Union Medical College Hospital, Beijing 100730, China.
authors.forename: X
authors.initials: X
authors.lastname: Hong
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Li
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000453:epidemiology*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004967:Estrogens / Q000097:blood*; D005260:Female; D006801:Humans; D008593:Menopause / Q000097:blood; D008875:Middle Aged; D015999:Multivariate Analysis; D017698:Postmenopause / Q000097:blood; D012306:Risk
chemical_list: D004967:Estrogens