title: Impaired circadian variations of haemostatic and fibrinolytic parameters in tetraplegia.
abstract: Spinal cord injured patients are at increased risk of developing deep vein thrombosis (DVT). Whether these patients have increased blood levels of prothrombotic markers remains to be clarified. In general, the risk of developing DVT is highest in the morning hours. In healthy humans, several haemostatic and fibrinolytic parameters exhibit circadian variations, but it is not known whether this also applies to those with spinal cord injury. The aim of the present study was to examine possible circadian variations in prothrombotic markers in tetraplegic patients. We studied six patients with complete tetraplegia and eight control subjects with repetitive blood sampling over a 24 h period. While the control subjects showed marked circadian variations in factor VIII activity, prothrombin fragments 1+2 and D-dimer levels, the tetraplegic patients did not (P < 0.05). Circadian variation in plasminogen activator inhibitor type-1 was present in both groups, being most marked (P < 0.05) in tetraplegia. We conclude that the circadian variations of several factors of the haemostatic and fibrinolytic systems are impaired in spinal cord injury. This could possibly reflect a deregulated autonomic nervous system, leading to a dysfunctional link between central and peripheral circadian oscillators.
authors.affiliation: Department of Haematology, Ullevaal University Hospital, Oslo, Norway. poiversen@hotmail.com
authors.forename: Per Ole
authors.initials: PO
authors.lastname: Iversen
authors.forename: Patricia D E
authors.initials: PD
authors.lastname: Groot
authors.forename: Nils
authors.initials: N
authors.lastname: Hjeltnes
authors.forename: Trine Opstad
authors.initials: TO
authors.lastname: Andersen
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Mowinckel
authors.forename: Per Morten
authors.initials: PM
authors.lastname: Sandset
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D005169:Factor VIII / Q000378:metabolism; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D005342:Fibrinolysis; D006487:Hemostasis; D006801:Humans; D008297:Male; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011782:Quadriplegia / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D012307:Risk Factors; D013119:Spinal Cord Injuries / Q000097:blood / Q000150:complications; D020246:Venous Thrombosis / Q000209:etiology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D017395:Plasminogen Activator Inhibitor 1; C036309:fibrin fragment D; D005169:Factor VIII; D005340:Fibrinogen