Inverse Association of Physical Fitness with Plasma Fibrinogen Level in Children The Columbia University BioMarkers Study.

Plasma fibrinogen has emerged as a risk factor for cardiovascular disease in adults, but relatively little is known about the correlates of plasma fibrinogen level in childhood. In the Columbia University BioMarkers Study (1994–1998), the authors evaluated the association between physical fitness and plasma fibrinogen level in 193 children 4–25 years old; 68% were Hispanic and 46% male. Fitness level assessed by treadmill testing was inversely associated with plasma fibrinogen (r = −0.24, p < 0.001). Plasma fibrinogen levels showed a graded inverse relation with tertiles of fitness assessed by treadmill (p < 0.001). In multivariate analyses, after adjustment for age, sex, race/ethnicity, body mass index, and presence of the A allele in the −455 position of the β-fibrinogen promoter gene, the fitness level remained inversely associated with plasma fibrinogen level (β = −1.3, 95% confidence interval (CI): −2.3, −0.34). Resting heart rate was also correlated with plasma fibrinogen level (r = 0.18, p < 0.05). Fibrinogen levels (mg/dl) increased over tertiles of resting heart rate (p = 0.002) and were significantly associated with resting heart rate in multivariate analysis (β = 0.82, 95% CI: 0.17, 1.5). These findings indicate that plasma fibrinogen is inversely associated with physical fitness in children independent of body mass index. Am J Epidemiol 2000;152:212–18. [ABSTRACT FROM PUBLISHER]