title: Role of hemostatic factors on the risk of venous thrombosis in people with impaired kidney function.
abstract: BACKGROUND
  Factors explaining the association between impaired kidney function and venous thrombosis have not been identified so far. The aim of our study was to determine whether the association between impaired kidney function and venous thrombosis can be explained by the concurrent presence of genetic or acquired venous thrombosis risk factors.
  
  
  RESULTS
  The glomerular filtration rate was estimated (eGFR) in 2473 venous thrombosis patients and 2936 controls from a population-based case-control study. Kidney function was grouped into 6 categories based on percentiles of the eGFR in the controls (>50th [reference], 10th-50th, 5th-10th, 2.5th-5th, 1st-2.5th, and <1st percentile). Several hemostatic factors showed a procoagulant shift with decreasing kidney function in controls, most notably factor VIII and von Willebrand factor. Compared with eGFR >50th percentile, factor VIII levels (adjusted mean difference, 60 IU/dL for the <1st eGFR percentile category) and von Willebrand factor levels (adjusted mean difference, 60 IU/dL for the <1st eGFR percentile category) increased with each percentile category. The odds ratios for venous thrombosis similarly increased across the categories from 1.1 (95% confidence interval, 0.9-1.3) for the 10th to 50th percentile to 3.7 (95% confidence interval, 2.4-5.7) for the <1st percentile category. Adjustment for factor VIII or von Willebrand factor attenuated these odds ratios, indicating an effect of eGFR on thrombosis through these factors. Adjustments for other risk factors for venous thrombosis did not affect the odds ratios.
  
  
  CONCLUSIONS
  Impaired kidney function affects venous thrombosis risk via concurrently raised factor VIII and von Willebrand factor levels.
authors.affiliation: Departments of Clinical Epidemiology (G.O., C.Y.V., W.M.L., M.V., F.W.D., F.R.R., S.C.C.) and Thrombosis and Haemostasis (F.R.R.), Leiden University Medical Center, Leiden, The Netherlands; and Division of Biomedical Genetics, Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands (C.Y.V.).
authors.forename: Gürbey
authors.initials: G
authors.lastname: Ocak
authors.forename: Carla Y
authors.initials: CY
authors.lastname: Vossen
authors.forename: Willem M
authors.initials: WM
authors.lastname: Lijfering
authors.forename: Marion
authors.initials: M
authors.lastname: Verduijn
authors.forename: Friedo W
authors.initials: FW
authors.lastname: Dekker
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Cannegieter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006487:Hemostasis / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000502:physiology; D007674:Kidney Diseases / Q000453:epidemiology* / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000378:metabolism* / Q000503:physiopathology; D055815:Young Adult; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D014841:von Willebrand Factor; D005169:Factor VIII
keywords: blood coagulation; epidemiology; renal insufficiency, chronic; venous thrombosis