title: Inflammatory cytokines as risk factors for a first venous thrombosis: a prospective population-based study.
abstract: BACKGROUND
  In case-control studies, elevated levels of interleukins 6 and 8 have been found to be associated with an increased risk of venous thrombosis (VT). Because of the design of these studies, it remained uncertain whether these alterations were a cause or a result of the VT. In order to distinguish between the two, we set out to measure the levels of six inflammatory markers prior to thrombosis in a population-based cohort using a nested case-cohort design.
  
  
  RESULTS
  Between August 1995 and June 1997, blood was collected from 66,140 people in the second Norwegian Health Study of Nord-Trøndelag (HUNT2). We identified venous thrombotic events occurring between entry and 1 January 2002. By this date we had registered 506 cases with a first VT; an age- and sex-stratified random sample of 1,464 controls without previous VT was drawn from the original cohort. Levels of interleukins 1beta, 6, 8, 10, 12p70, and tumour necrosis factor-alpha were measured in the baseline sample that was taken 2 d to 75 mo before the event (median 33 mo). Cut-off points for levels were the 80th, 90th, and 95th percentile in the control group. With odds ratios ranging from 0.9 (95% CI: 0.6-1.5) to 1.1 (95% CI: 0.7-1.8), we did not find evidence for a relationship between VT and an altered inflammatory profile.
  
  
  CONCLUSIONS
  The results from this population sample show that an altered inflammatory profile is more likely to be a result rather than a cause of VT, although short-term effects of transiently elevated levels cannot be ruled out.
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands.
authors.forename: Sverre C
authors.initials: SC
authors.lastname: Christiansen
authors.forename: Inger Anne
authors.initials: IA
authors.lastname: Naess
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Cannegieter
authors.forename: Jens
authors.initials: J
authors.lastname: Hammerstrøm
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
authors.forename: Pieter H
authors.initials: PH
authors.lastname: Reitsma
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D016022:Case-Control Studies; D016001:Confidence Intervals; D016207:Cytokines / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011153:Population; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D020246:Venous Thrombosis / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D016207:Cytokines