title: Estrogen levels do not correlate with improvement in cognition.
abstract: OBJECTIVE
  To investigate whether an association exists between estradiol and estrone levels and measures of cognitive functioning in women with Alzheimer disease (AD) treated with conjugated equine estrogen (Premarin; Wyeth-Ayerst, Philadelphia, Pa).
  
  
  METHODS
  We studied 120 postmenopausal women who underwent hysterectomy and who had AD treated with Premarin for 1 year. Plasma estradiol and estrone levels were determined at multiple points during the 1-year treatment trial. The change from baseline level at 2 and 12 months was associated with the change score on 7 different assessments of cognitive functioning.
  
  
  RESULTS
  At baseline, estradiol levels were low and there were no associations between the estradiol level and the 7 neuropsychological measures. A similar pattern was observed for estrone treatment. During treatment with 0.625 mg/d of Premarin, estradiol levels increased about 4-fold; while receiving 1.25 mg/d of Premarin, estradiol levels increased about 8-fold. A similar pattern was seen with estrone treatment. For both estradiol and estrone levels, there were no significant associations between the change in plasma level and the change in neuropsychological test scores at either 2 or 12 months.
  
  
  CONCLUSIONS
  Although Premarin elevated estradiol and estrone levels, there was no association between hormone levels and cognitive functioning after either 2 or 12 months of treatment.
authors.affiliation: Department of Neurosciences, University of California, San Diego, School of Medicine, 9500 Gilman Dr, La Jolla, CA 92093, USA. lthal@ucsd.edu
authors.forename: Leon J
authors.initials: LJ
authors.lastname: Thal
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Thomas
authors.forename: Ruth
authors.initials: R
authors.lastname: Mulnard
authors.forename: Mary
authors.initials: M
authors.lastname: Sano
authors.forename: Michael
authors.initials: M
authors.lastname: Grundman
authors.forename: Lon
authors.initials: L
authors.lastname: Schneider
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage / Q000494:pharmacology*; D004970:Estrone / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D017698:Postmenopause
chemical_list: D004966:Estrogens, Conjugated (USP); D004970:Estrone; D004958:Estradiol