American Journal of Epidemiology Advance Access published online on September 4, 2007
American Journal of Epidemiology, doi:10.1093/aje/kwm191
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Associations of Plasma Fibrinogen Levels with Established Cardiovascular Disease Risk Factors, Inflammatory Markers, and Other Characteristics: Individual Participant Meta-Analysis of 154,211 Adults in 31 Prospective Studies
The Fibrinogen Studies Collaboration
Received for publication January 17, 2007. Accepted for publication May 11, 2007.Long-term increases in plasma fibrinogen levels of 1 g/liter are associated with an approximate doubling of risk of major cardiovascular disease outcomes, but causality remains uncertain. To quantify cross-sectional associations of fibrinogen levels with established risk factors and other characteristics, the investigators combined individual data on 154,211 apparently healthy adults from 31 prospective studies conducted between 1967 and 2003, using a linear mixed model that included random effects at the cohort level. Fibrinogen levels increased with age and showed continuous, approximately linear relations with several risk markers and slightly curvilinear associations with log triglycerides, albumin, and tobacco and alcohol consumption. Female sex, Black ethnicity, lower socioeconomic status, and alcohol abstinence were each associated with modestly higher fibrinogen levels. Approximately one third of the variation in fibrinogen levels was explained by cohort, age, and sex. An additional 7% was explained by established risk factors (notably, positive associations with smoking and body mass index and an inverse association with high density lipoprotein cholesterol), and a further 10% was explained by inflammatory markers (notably, a positive association with C-reactive protein). The association with body mass index was twice as strong in women as in men, whereas the association with smoking was much stronger in men. These findings substantially advance understanding of the correlates and possible determinants of fibrinogen levels.
association; cohort studies; fibrinogen; meta-analysis; prospective studies; risk factors
Abbreviations: BMI, body mass index; FSC, Fibrinogen Studies Collaboration; HDL, high density lipoprotein; LDL, low density lipoprotein
Correspondence to Dr. Stephen Kaptoge, FSC Coordinating Centre, Department of Public Health and Primary Care, University of Cambridge, Strangeways Site, Worts Causeway, Cambridge CB1 8RN, United Kingdom (e-mail: skk22{at}medschl.cam.ac.uk).