title: Vitamin K administration to elderly patients with osteoporosis induces no hemostatic activation, even in those with suspected vitamin K deficiency.
abstract: The administration of menaquinone-4 (MK-4), one of subclasses of vitamin K2, significantly reduces bone loss in postmenopausal osteoporotic women. However, concerns have been raised about whether vitamin K administration alters the hemostatic balance by inducing a thrombotic tendency. We investigated were whether the administration of vitamin K in the form of MK-4 induced a thrombotic tendency in 29 elderly patients with osteoporosis (5 men, 24 women; age range 78.7+/-5.1 years). Patients were administered 45 mg/day (three times a day, 30 min after each meal) of MK-4 for 12 weeks. Blood samples were obtained from the patients at 0, 4 and 12 weeks after the start of MK-4 administration. A number of hemostatic parameters remained stable under the markedly increased plasma levels of MK-4. However, in patients with suspected vitamin K deficiency, whose plasma levels of vitamin K or factor VII were low, vitamin-K-dependent clotting factors such as factor VII and prothrombin were gradually increased after administration of MK-4. No changes in the sensitive molecular markers such as TAT and F1+2, which reflect the amount of thrombin generated in the blood stream, were observed, even in those patients with suspected vitamin K deficiency. These results indicate that MK-4 can be administered safely, with regard to maintaining the hemostatic balance, to osteoporotic patients receiving no anticoagulant therapy.
authors.affiliation: Department of Internal Medicine (III), Kanazawa University School of Medicine, Japan. hasakura@med3.m.kanazawa-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Asakura
authors.forename: S
authors.initials: S
authors.lastname: Myou
authors.forename: Y
authors.initials: Y
authors.lastname: Ontachi
authors.forename: T
authors.initials: T
authors.lastname: Mizutani
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Saito
authors.forename: E
authors.initials: E
authors.lastname: Morishita
authors.forename: M
authors.initials: M
authors.lastname: Yamazaki
authors.forename: S
authors.initials: S
authors.lastname: Nakao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001779:Blood Coagulation Factors / Q000378:metabolism; D003487:Cyanoacrylates / Q000378:metabolism; D005260:Female; D006487:Hemostasis / Q000187:drug effects*; D006490:Hemostatics / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000150:complications / Q000188:drug therapy; D010837:Vitamin K 1 / Q000097:blood; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use*; D014813:Vitamin K Deficiency / Q000097:blood* / Q000150:complications
chemical_list: D001779:Blood Coagulation Factors; D003487:Cyanoacrylates; D006490:Hemostatics; D024482:Vitamin K 2; C007166:cyacrin; C030814:menatetrenone; D010837:Vitamin K 1