Inflammatory cytokines as risk factors for a first venous thrombosis: a prospective population-based study.
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.
Christiansen
Sverre C
SC
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands.
Naess
Inger Anne
IA
Cannegieter
Suzanne C
SC
Hammerstrøm
Jens
J
Rosendaal
Frits R
FR
Reitsma
Pieter H
PH
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*
D015415:Biomarkers; D016207:Cytokines