title: Climacteric lowers plasma levels of platelet-derived microparticles: a pilot study in pre- versus postmenopausal women.
abstract: BACKGROUND
  Climacteric increases the risk of thrombotic events by alteration of plasmatic coagulation. Up to now, less is known about changes in platelet- (PMP) and endothelial cell-derived microparticles (EMP).
  
  
  METHODS
  In this prospective study, plasma levels of microparticles (MP) were compared in 21 premenopausal and 19 postmenopausal women.
  
  
  RESULTS
  No altered numbers of total MP or EMP were measured within the study groups. However, the plasma values of CD61-exposing MP from platelets/megakaryocytes were higher in premenopausal women (5,364 × 10(6)/l, range 4,384-17,167) as compared to postmenopausal women (3,808 × 10(6)/l, range 2,009-8,850; p = 0.020). This differentiation was also significant for the subgroup of premenopausal women without hormonal contraceptives (5,364 × 10(6)/l, range 4,223-15,916; p = 0.047; n = 15). Furthermore, in premenopausal women, higher plasma levels of PMP exposing CD62P were also present as compared to postmenopausal women (288 × 10(6)/l, range 139-462, vs. 121 × 10(6)/l, range 74-284; p = 0.024). This difference was also true for CD63+ PMP levels (281 × 10(6)/l, range 182-551, vs. 137 × 10(6)/l, range 64-432; p = 0.015).
  
  
  CONCLUSIONS
  Climacteric lowers the level of PMP but has no impact on the number of EMP in women. These data suggest that PMP and EMP do not play a significant role in enhancing the risk of thrombotic events in healthy, postmenopausal women.
authors.affiliation: Department of Clinical Chemistry, Academic Medical Center, Amsterdam, The Netherlands. andreas.rank@klinikum-augsburg.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Rank
authors.forename: Rienk
authors.initials: R
authors.lastname: Nieuwland
authors.forename: Sabine
authors.initials: S
authors.lastname: Roesner
authors.forename: Katharina
authors.initials: K
authors.lastname: Nikolajek
authors.forename: Erhard
authors.initials: E
authors.lastname: Hiller
authors.forename: Bettina
authors.initials: B
authors.lastname: Toth
mesh_terms: D000293:Adolescent; D000328:Adult; D001792:Blood Platelets / Q000378:metabolism*; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D002979:Climacteric; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D039661:Integrin beta3 / Q000378:metabolism; D008533:Megakaryocytes / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism; D010865:Pilot Projects; D017698:Postmenopause; D017697:Premenopause; D060149:Tetraspanin 30 / Q000378:metabolism; D055815:Young Adult
chemical_list: D039661:Integrin beta3; D019007:P-Selectin; D060149:Tetraspanin 30