title: Gender differences in hemorheological parameters and in in vitro platelet aggregation in acetylsalicylic acid and clopidogrel treated vascular patients.
abstract: BACKGROUND
  Sex-specific response to antiplatelet medications have been reported in several previous studies.
  
  
  OBJECTIVE
  We investigated a possible connection between gender differences in hemorheological parameters and in vitro platelet aggregation in vascular patients treated with widely used antiplatelet agents.
  
  
  METHODS
  In vitro platelet aggregation was assessed in 2687 patients treated with 100 mg acetylsalicylic acid (ASA), 1047 patients treated with 75 mg clopidogrel and 311 patients on dual antiplatelet therapy (100 mg aspirin and 75 mg clopidogrel) according to the method of Born. In subgroups of patients fibrinogen concentration, whole blood and plasma viscosity, red blood cell aggregation and hematocrit were simultaneously measured. The subjects were divided into groups according to their gender.
  
  
  RESULTS
  ADP induced platelet aggregation was significantly higher in women in the case of ASA treatment (p<0.001). No gender differences could be observed in platelet function in patients treated with clopidogrel or on dual antiplatelet therapy. Hematocrit and whole blood viscosity were significantly higher in men in all groups (p<0.001), while no significant gender differences were observed in red blood cell aggregation indices in either group. Fibrinogen concentration was significantly higher in women than in men among patients treated with 100 mg ASA (p<0.05), but not in the other groups.
  
  
  CONCLUSIONS
  Significantly higher fibrinogen concentration found in aspirin treated women than men may play a role in higher ADP induced platelet aggregation. Gender differences in response to monotherapy suggest that benefits from combination therapy may be greater in females. The clinical relevance of higher ADP induced platelet aggregation in women treated with ASA needs further investigation.
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Koltai
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Papp
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Peter
authors.initials: P
authors.lastname: Kenyeres
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary Department of Neurology, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Gergely
authors.initials: G
authors.lastname: Feher
authors.affiliation: Department of Public Health, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Antal
authors.initials: A
authors.lastname: Tibold
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary Division of Cardiology, Emory University, Atlanta, GA, USA.
authors.forename: Tamas
authors.initials: T
authors.lastname: Alexy
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Marton
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Gabor
authors.initials: G
authors.lastname: Kesmarky
authors.affiliation: 1st Department of Medicine, School of Medicine, University of Pécs, Pécs, Hungary.
authors.forename: Kalman
authors.initials: K
authors.lastname: Toth
mesh_terms: D000368:Aged; D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use*; D000077144:Clopidogrel; D004903:Erythrocyte Aggregation; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006400:Hematocrit; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D012212:Rheology; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D010975:Platelet Aggregation Inhibitors; D005340:Fibrinogen; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin
keywords: Aspirin; erythrocyte aggregation; fibrinogen; optical aggregometry; thienopyridines; viscosity