title: Changes in Lp(a) lipoprotein and lipid levels after cessation of female sex hormone production and estrogen replacement therapy.
abstract: OBJECTIVE
  To investigate the serial changes in Lp(a) lipoprotein levels with the loss of female sex hormones by surgical menopause and with estrogen replacement therapy in the same woman.
  
  
  METHODS
  Forty-four premenopausal women who underwent a transabdominal hysterectomy (TAH) because of benign gynecological disorders were divided into two groups: women who underwent a TAH and unilateral salpingo-oophorectomy (n=31) and women who underwent a TAH and bilateral salpingo-oophorectomy (n=13). In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, 0.625 mg of conjugated equine estrogen was given daily 2 months after the operation. The levels of Lp(a) lipoprotein and lipids were measured before and at 2 and 4 months after the operation.
  
  
  RESULTS
  In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, the mean (+/-SD) concentration of Lp(a) lipoprotein was increased by 24.5% from 0.48+/-0.47 mmol/L (18.4+/-18.3 mg/dL) to 0.59+/-0.54 mmol/L (22.9+/-21.0 mg/dL) after 2 months (P<.05), and it was reduced by 30.6% to 0.41+/-0.51 mmol/L (15.9+/-20.1 mg/dL)(P<.005) with therapy with conjugated equine estrogen (Premarin). The Lp(a) lipoprotein levels were not changed in the group of women who underwent a TAH and unilateral salpingo-oophorectomy. In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, the high density lipoprotein cholesterol level showed a trend of increase after 2 months from 1.45+/-0.48 mmol/L (56.1+/-18.5 mg/dL) to 1.58+/-0.309 mmol/L (61.2+/-15.1 mg/dL) without statistical significance, and it revealed a significant elevation to 1.76+/-0.43 mmol/L (68.2+/-16.8 mg/dL) with therapy with conjugated equine estrogen (Premarin) compared with that of the basal level (P<.05).
  
  
  CONCLUSIONS
  tHE Lp(a) lipoprotein levels appear to be closely associated with female sex hormones. This association might play a pivotal role in postmenopausal increases of atherosclerotic diseases and cardioprotective effect of estrogen in postmenopausal women.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chung-Ang University Medical Center, Seoul, Korea.
authors.forename: C J
authors.initials: CJ
authors.lastname: Kim
authors.forename: W S
authors.initials: WS
authors.lastname: Ryu
authors.forename: J W
authors.initials: JW
authors.lastname: Kwak
authors.forename: C T
authors.initials: CT
authors.lastname: Park
authors.forename: U H
authors.initials: UH
authors.lastname: Ryoo
mesh_terms: D000328:Adult; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000502:physiology*; D005187:Fallopian Tubes / Q000601:surgery; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008055:Lipids / Q000097:blood*; D017270:Lipoprotein(a) / Q000097:blood / Q000187:drug effects*; D008875:Middle Aged; D010052:Ovariectomy; D011184:Postoperative Period; D017697:Premenopause; D011446:Prospective Studies
chemical_list: D004967:Estrogens; D008055:Lipids; D017270:Lipoprotein(a)