LEISURE-TIME PHYSICAL-ACTIVITY BUT NOT WORK-RELATED PHYSICAL-ACTIVITYIS ASSOCIATED WITH DECREASED PLASMA VISCOSITY - RESULTS FROM A LARGE POPULATION-SAMPLE

Background Regular leisure-time physical activity (LTPA) is inversely associated with coronary heart disease (CHD). This has been mainly exp lained by its impact on traditional CHD risk factors, but more recentl y it was also shown to lower fibrinogen, which largely determines plas ma viscosity. No data on the effect of work activity (WA) on plasma vi scosity have been published. Methods and Results We studied the relati onship between self-reported LTPA or WA and plasma viscosity as well a s other CHD risk factors in 3522 men and women age 25 to 64 years. Phy sical activity was assessed by questionnaire. LTPA was inversely assoc iated with plasma viscosity in both sexes. The unadjusted mean differe nces in plasma viscosity in men between no activity and the highest ac tivity were 0.024 mPa . s (95% confidence interval [CI], 0.016 to 0.03 2 mPa . s, P<.001) during winter and 0.024 mPa . s (95% CI, 0.016 to 0 .031 mPa . s, P<.001) during summer. After adjustment for age, cholest erol, smoking, blood pressure, body mass index, and years of education , mean differences decreased but still remained substantial and statis tically significant (0.010 mPa . s; 95% CI, 0.003 to 0.018 mPa . s [P= .009] for winter activity; and 0.010 mPa . s; 95% CI, 0.002 to 0.017 m Pa . s [P=.011] for summer activity). Similar results were found in wo men. WA showed no appreciable association with plasma viscosity after controlling for the covariates. Conclusions LTPA is inversely associat ed with plasma viscosity, independent of other risk factors, whereas W A shows no material effect in men and women. Decreased plasma viscosit y may represent one mechanism through which LTPA confers a decrease of CHD risk.