Summary
The effects of chronic cigarette smoking on the coagulation system were examined in
2964 men aged 50 to 61 years and clinically free of cardiovascular disease. Factor
VII activity (VIIc), factor VII antigen (VIIag), prothrombin fragment 1+2 (F1.2), fibrinopeptide A (FPA) and fibrinogen were measured in all participants, and activated
factor VII (VIIa), factor IX activation peptide (IX pep) and factor X activation peptide
(X pep) in a large sub-sample. The levels of all indices except FPA differed significantly
between non-smokers, ex-smokers and current smokers. After adjustment for other conventional
cardiovascular risk factors, mean VIIc was raised slightly by 3% in ex-smokers and
current smokers as compared with non-smokers, owing to increases in VIIa and VIIag.
Plasma IX pep, X pep, F1.2 and fibrinogen concentration were highest in current smokers, intermediate in ex-smokers
and lowest in non-smokers. These findings accord with the increased risk of arterial
thrombosis in smokers.