Psychosocial job characteristics and plasma fibrinogen in Japanese male and female workers: the Jichi Medical School cohort study

The aim of the study was to explore the association between psychosocial job characteristics and plasma fibrinogen levels among 1588 male and 1677 female Japanese workers aged 65 and younger. Sociodemographic and behavioral variables were obtained by a standardized questionnaire, which included the Japanese version of the demand–control questionnaire. Fibrinogen levels were determined with a one-stage clotting assay kit. Job strain – a ratio of demand to control – was positively associated with plasma fibrinogen (p for trend < 0.05) but ANCOVA showed that the main effect was only marginally statistically significant in men. Analyses by individual job characteristics components revealed that men with a high level of job demand (Age-adjusted geometric mean (mg/dl) = 234.6, 95% CI: 230.9–238.2) showed a higher fibrinogen level than those with other levels (middle; 227.9, 223.6–232.3, low; 224.8, 220.5–229.1) (F (2, 1584) = 6.63, p < 0.001). Adjustment for potential confounders including total cholesterol and CRP did not reduce the association. No significant association was found between psychosocial job characteristics and fibrinogen in women. The findings appear to imply a mechanism through which adverse psychosocial job characteristics lead to cardiovascular diseases in men.