Relationship between plasma fibrinogen and fiber intake in the EPIC-Norfolk cohort

Background/Objectives: Fiber-rich diets have been proposed to lower circulating levels of inflammatory makers. Our objective was to investigate cross-sectional relationships between fiber intake and plasma fibrinogen. Subjects/Methods: We examined the relationship between plasma fibrinogen and dietary fiber in 20 960 men and women, aged 45-75 years old, living in Norfolk, UK. Fiber intake was assessed using a food frequency questionnaire. Results: Mean fibrinogen levels were lower across the increasing quartiles of the fiber intake after adjusting for age, sex, body mass index, physical activity, smoking status and alcohol consumption, and total calories, percentage of energy intake from carbohydrate, protein and fat, with a difference of 0.08 g/l fibrinogen between first and fourth quartiles (P for trend <0.001) for the whole population. When categorized by sex, the results for men were the same and for women, the results failed to be significant. In linear regression models, fibrinogen levels were significantly related to fiber intake for the whole population (-0.056 g/l, s.e = 0.012 per 10 g increase in fiber intake, P<0.001), but although the relations were in the same direction after adjusting for the same covariates above, they failed to be significant when smokers or women not using post-menopause hormone therapy were separately considered. Conclusions: Plasma fibrinogen levels appear to be inversely related to dietary fiber intake in middle-aged and older men and women. European Journal of Clinical Nutrition (2012) 66, 443-451; doi:10.1038/ejcn.2011.194; published online 23 November 2011