title: Plasma levels of protein S, protein C, and factor X: effects of sex, hormonal state and age.
abstract: We measured total and free protein S (PS), protein C (PC) and factor X (FX) in 393 healthy blood donors to assess differences in relation to sex, hormonal state and age. All measured proteins were lower in women as compared to men, as were levels in premenopausal women as compared to postmenopausal women. Multiple regression analysis showed that both age and subgroup (men, pre- and postmenopausal women) were of significance for the levels of total and free PS and PC, the subgroup effect being caused by the differences between the premenopausal women and the other groups. This indicates a role of sex-hormones, most likely estrogens, in the regulation of levels of pro- and anticoagulant factors under physiologic conditions. These differences should be taken into account in daily clinical practice and may necessitate different normal ranges for men, pre- and postmenopausal women.
authors.affiliation: Department of Haematology, University Hospital, Groningen, The Netherlands.
authors.forename: C M
authors.initials: CM
authors.lastname: Henkens
authors.forename: V J
authors.initials: VJ
authors.lastname: Bom
authors.forename: W
authors.initials: W
authors.lastname: Van der Schaaf
authors.forename: P M
authors.initials: PM
authors.lastname: Pelsma
authors.forename: C T
authors.initials: CT
authors.lastname: Sibinga
authors.forename: P J
authors.initials: PJ
authors.lastname: de Kam
authors.forename: J
authors.initials: J
authors.lastname: van der Meer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001782:Blood Donors; D005170:Factor X / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000032:analysis*; D017293:Protein S / Q000032:analysis*; D012737:Sex Factors
chemical_list: D011486:Protein C; D017293:Protein S; D005170:Factor X