13-year long-term associations between changes in traditional cardiovascular risk factors and changes in fibrinogen levels: The Coronary Artery Risk Development in Young Adults (CARDIA) study

Objective: Cross-sectional and prospective studies have linked cardiovascular events and traditional risk factors (TRFs) with higher plasma fibrinogen levels. In a young cohort, we sought to determine longitudinal associations between changes in/development of TRFs and fibrinogen levels over 13 years. Methods: We included 2525 adults from the CARDIA study, aged 25-37 with fibrinogen and TRFs measured at year 7 (study baseline; 1992-1993); and year 20 (follow-up). Multiple linear regressions were used to compare mean changes in fibrinogen to TRFs. Results: Mean fibrinogen increased by 71 mg/dL vs. 70 mg/dL (p = NS) in black vs. white men, and 78 mg/dL vs. 68 mg/dL (p < 0.05) in black vs. white women, respectively over 13 years. After multivariable adjustments, fibrinogen generally rose with increasing BMI (p < 0.001; all sex/race groups), LDL cholesterol, log triglycerides and diastolic blood pressure; and fell with increasing HDL cholesterol and physical activity. 13-year increase in fibrinogen for persons who quit smoking or became non-obese were comparable (p = NS) to that of never-smokers and never-obese persons. Conclusions: Among young black and white men and women with few baseline cardiovascular risk factors, fibrinogen tracked longitudinally with changes in TRFs over 13 years through middle age. There was a strong inverse longitudinal relationship between modifiable risk factors (weight loss/smoking cessation) and 13-year change in fibrinogen. Our study helps provide some insight into the role of fibrinogen as a disease marker in the associations between fibrinogen and CVD.