Physical activity and fibrinogen concentrations in 23,201 men and women in the EPIC-Norfolk population-based study

Objective: To examine the relationship between usual physical activity and fibrinogen concentrations in a free-living population of men and women. Methods and results: We examined the cross-sectional relationship between habitual combined work and leisure physical activity derived from a validated physical activity questionnaire and plasma fibrinogen concentrations in a population-based study of 23,201 men and women aged 40-79 years. Mean plasma fibrinogen concentrations were lower in people who were physically active compared to those who were physically less active. Mean fibrinogen concentrations were 2.82 +/- 0.02, 2.87 +/- 2.87(0.02), 2.90 +/- 0.02, and 2.97 +/- 0.02 g/L (p for trend < 0.0001) for men in the active, moderately active, moderately inactive and inactive physical activity categories respectively, independently of age, smoking, body mass index (BMI), prevalent illnesses, social class and alcohol consumption. The corresponding values for women were 2.95 +/- 0.02, 2.94 +/- 0.01, 2.98 +/- 0.01, and 3.04 +/- 0.01 g/L (p for trend < 0.0001). Similar results were observed after adjusting for hormone replacement therapy (HRT) in women. Conclusions: Higher physical activity is significantly inversely associated with plasma fibrinogen concentration independently of other related factors. This might provide an additional plausible mechanism for the cardiovascular health benefits of physical activity. (C) 2007 Elsevier Ireland Ltd. All rights reserved.