Leisure time physical activity, cardiorespiratory fitness, and plasma fibrinogen concentrations in nonsmoking middle-aged men

Purpose: The relationship of both leisure time physical activity and predic ted maximum oxygen consumption ((V) over dotO(2max)) with plasma fibrinogen concentration was examined within a cohort of employed middle-aged men. Me thods: Analyses were performed on a subsample of 635 nonsmoking men (46.7 /- 7.7 yr) who completed a preventive medical assessment between 1992 and 1 996. Results: Among nonsmokers, mean age-adjusted fibrinogen concentration decreased significantly with higher physical activity index (PAI) categorie s and quartiles of predicted (V) over dotO(2max) (mL . kg(-1) . min(-1)) (b oth P = 0.001). Mean age-adjusted plasma fibrinogen concentrations were sig nificantly different (P < 0.05) between inactive and vigorous PAI groups an d extreme quartiles of predicted (V) over dotO(2max) (mL . kg(-1) . min(-1) ). These relationships were no longer significant after adjustment for the confounding effect of other ischemic heart disease risk factors. Stepwise m ultiple regression analyses showed that age, sum of skinfolds, and blood le ukocyte count were the strongest predictors of plasma fibrinogen concentrat ion. Conclusion: These data do not confirm a significant independent associ ation of both physical activity and predicted (V) over dotO(2max) (mL . kg( -1) . min(-1)) with fibrinogen concentrations among nonsmoking middle-aged men of similar high social class.