title: Risk of Alzheimer's disease among users of postmenopausal hormone therapy: A nationwide case-control study.
abstract: OBJECTIVE
  To examine the association between postmenopausal hormone therapy (HT) and Alzheimer's disease (AD).
  
  
  METHODS
  Medicine and Alzheimer's disease (MEDALZ) is a nested case-control study of the entire Finnish population with clinically verified AD from 2005 to 2011 and up to 4 matched controls per case. This study comprises 230,580 women (46,117 cases and 184,463 controls). Data on HT use from 1995 to 2011 was extracted from the national prescription register using following ATC codes: G03C (estrogen), G03D (progestogen) and G03F (estrogen and progestogen in combination). Only systemic HT (oral or transdermal) was considered.
  
  
  RESULTS
  Use of systemic estrogen and progestogen was associated with an increased risk of AD, with ORs (95% CI) of 1.10 (1.06-1.12) and 1.13 (1.10-1.17) respectively, but use of systemic estrogen HT for >10years (OR, 95% CI: 0.91, 0.84-0.99) was protective against AD. Long-term (>10years) use of progestogen and combination HT was not related to AD risk (OR, 95% CI: 1.0, 0.90-1.2).
  
  
  CONCLUSIONS
  Our findings do not suggest HT is an important determinant of AD risk.
authors.affiliation: Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland. Electronic address: bushra.imtiaz@uef.fi.
authors.forename: Bushra
authors.initials: B
authors.lastname: Imtiaz
authors.affiliation: Kuopio Research Center of Geriatric Care, University of Eastern Finland, Kuopio, Finland; Research Center for Comparative Effectiveness and Patient Safety (RECEPS) and School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Taipale
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Antti
authors.initials: A
authors.lastname: Tanskanen
authors.affiliation: School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
authors.forename: Miia
authors.initials: M
authors.lastname: Tiihonen
authors.affiliation: Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland; Division of Clinical Geriatrics, Center for Alzheimer Research, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Miia
authors.initials: M
authors.lastname: Kivipelto
authors.affiliation: Terveystalo, Finland.
authors.forename: Anna-Mari
authors.initials: AM
authors.lastname: Heikkinen
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Tiihonen
authors.affiliation: Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland; Neurocenter, Neurology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Hilkka
authors.initials: H
authors.lastname: Soininen
authors.affiliation: Kuopio Research Center of Geriatric Care, University of Eastern Finland, Kuopio, Finland; School of Pharmacy, Social Pharmacy, University of Eastern Finland, Kuopio, Finland.
authors.forename: Sirpa
authors.initials: S
authors.lastname: Hartikainen
authors.affiliation: Research Center for Comparative Effectiveness and Patient Safety (RECEPS) and School of Pharmacy, University of Eastern Finland, Kuopio, Finland.
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Tolppanen
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011372:Progestins / Q000009:adverse effects; D012307:Risk Factors; D016387:Women's Health
chemical_list: D004967:Estrogens; D011372:Progestins
keywords: Alzheimer’s disease; Estrogen; Gynecological surgery; Hormone therapy; Menopause; Progestogen