THE ACUTE RISE IN PLASMA-FIBRINOGEN CONCENTRATION WITH EXERCISE IS INFLUENCED BY THE G-(453)-A POLYMORPHISM OF THE BETA-FIBRINOGEN GENE

We have investigated the effects of chronic physical training and acut e intensive exercise on plasma fibrinogen levels and the relationship of these responses to beta-fibrinogen G-453-A polymorphism genotype. O ne hundred fifty-six male British Army recruits were studied at the st art of their 10-week basic training, which emphasizes physical fitness . Cohorts were restudied between 0.5 and 5 days after a major 2-day st renuous military exercise (ME) undertaken in their final week of train ing. Changes in fibrinogen concentration were adjusted for the effects of age, body mass index, and smoking history. Compared with baseline values, fibrinogen concentrations were significantly lower (11.9%, P=. 04) at day 5 after ME, consistent with the beneficial effect of traini ng. However, they were higher on days 1 through 3 after ME (suggesting an ''acute-phase'' response to strenuous exercise) and were maximal o n days 1 and 2 (27.2%, P<.001 and 37.1%, P<.001, respectively). Fibrin ogen genotype was available in 149 individuals. As expected from previ ous studies, men with one or more fibrinogen gene A-453 alleles had pl asma fibrinogen concentrations slightly but not significantly higher a t baseline (4.5%, P=.11). During the acute-phase response (days 2 and 3), however, the degree of rise was strongly related to the presence o f the A allele, being 26.7+/-5.4% (mean+/-SE), 36.5+/-11.0%, and 89.2/-30.7 for the GG, GA, and AA genotypes, respectively (P=.01). These r esults confirm that chronic exercise training lowers plasma fibrinogen levels, that intensive exercise generates an acute-phase rise in leve ls, and that this acute response is strongly influenced by the G/A pol ymorphism of the beta-fibrinogen gene.