title: Effects of long-term estrogen replacement therapy on growth hormone response to pyridostigmine in healthy postmenopausal women.
abstract: OBJECTIVE
  There is growing evidence that estrogen may protect against age-related cognitive decline and reduce the risk of developing Alzheimer's disease (AD) in healthy, postmenopausal women. The underlying biological basis for this is not known but may include preservation of cholinergic systems. Cholinergic dysfunction has been implicated in the aetiology of age-related memory impairment and AD. We studied the effect of prolonged use of estrogen replacement therapy (ERT) on central cholinergic tone in healthy postmenopausal women.
  
  
  METHODS
  Growth hormone (GH) responses to oral pyridostigmine (120 mg) were measured over a 3 h period in thirty healthy postmenopausal women, 15 on long-term ERT and 15 ERT naïve.
  
  
  RESULTS
  GH release following pyridostigmine was significantly larger in ERT treated women than in ERT naïve women. In addition within the ERT treated group there was a significant positive correlation between duration of estrogen treatment and GH response.
  
  
  CONCLUSIONS
  Long-term ERT can enhance cholinergic function in postmenopausal women and this may be related to duration of estrogen treatment. Modulation of central cholinergic function may be one mechanism by which long-term ERT could preserve cognitive function in healthy, postmenopausal women.
authors.affiliation: Department of Psychological Medicine, Institute of Psychiatry, London, UK. t.a.vanamelsvoort@amc.uva.nl
authors.forename: T
authors.initials: T
authors.lastname: van Amelsvoort
authors.forename: D G M
authors.initials: DG
authors.lastname: Murphy
authors.forename: D
authors.initials: D
authors.lastname: Robertson
authors.forename: E
authors.initials: E
authors.lastname: Daly
authors.forename: M
authors.initials: M
authors.lastname: Whitehead
authors.forename: K
authors.initials: K
authors.lastname: Abel
mesh_terms: D000368:Aged; D000375:Aging; D002800:Cholinesterase Inhibitors; D004958:Estradiol / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007700:Kinetics; D008593:Menopause; D011729:Pyridostigmine Bromide; D013997:Time Factors
chemical_list: D002800:Cholinesterase Inhibitors; D019382:Human Growth Hormone; D004958:Estradiol; D011729:Pyridostigmine Bromide; D006854:Hydrocortisone