Summary
The relations between habitual physical activity (PA), fibrinogen gene polymorphisms
and plasma fibrinogen were investigated in 191 postmenopausal women. Subjects who
reported PA at least 4 times/ week had lower fibrinogen level (3.19 g/1; 95% Cl 3.10;
3.27) than women reporting PA 2-3 times/week (3.43 g/1; 3.29; 3.58) or sedentary subjects
(3.64 g/1; 3.33; 3.94). There were no differences in plasma fibrinogen across the
α-fibrinogen (Rsal, TaqI) or (β-fibrinogen (Mnll, Bell, Hindlll) genotypes, the frequencies
of which were in a Hardy- Weinberg equilibrium. An interaction between Rsal, which
was in complete linkage disequilibrium with TaqI, and PA on plasma fibrinogen was
observed, even after adjustments for BMI, smoking and medication (p = 0.024). Among
women homozygous for the common Rsal allele, the physically most active had lower
fibrinogen level (p <0.001) compared to the physically less active subjects. These
results suggest that, in postmenopausal women, the relation between physical activity
and plasma fibrinogen is modulated by genetic variation in the α-fibrinogen gene.
