Plasma fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor 1, and their related factors in three Japanese population samples

To examine population mean variations in plasma fibrinogen and fibrinolytic variables, and their rela tions with cardiovascular risk characteristics among Japanese middle-aged men, a cross-sectional study was conducted for a total of 245 men aged 50-59 years in three population-based samples: residents in rural communities of northeast and central Japan and urban white-collar workers. Age-adjusted mean value of plasma fibrinogen, tissue plasminogen activator antigen (t-PA antigen), plasminogen activator inhibitor 1 antigen (PAI-1 antigen) did not differ significantly among the populations. Mean value of tissue plasminogen activator activity (t-PA activity) was lower in central rural residents than in northeast rural men. According to multiple linear regression analyses, there were positive associations of t-PA and PAI-1 antigens with serum triglyceride levels, serum insulin and waist-hip ratio within each population and the total samples. A positive association between these fibrinolytic variables and usual ethanol intake was also observed. Smoking was significantly associated with plasma fibrinogen and PAI-1 antigen but not with t-PA antigen or activity. Activity of t-PA was inversely associated with body mass index, and a mean difference in t-PA activity was in part explained by a mean difference in body mass index. In conclusion, population mean values of plasma fibrinogen and fibrinolytic variables did not differ among three Japanese populations except for mean t-PA activity. Reduced fibrinolysis expressed as increased PAI-1 antigen was associated with smoking and the status of insulin resistance, such as high levels of serum insulin, serum triglycerides and waist-hip ratio.