Associations of C-reactive protein and fibrinogen with mortality from all-causes, cardiovascular disease and cancer among U.S. adults.

C-reactive protein (CRP) and fibrinogen are associated with an increased risk of death with suggested differences by gender, diet quality and race/ethnicity. However, the current evidence is limited. We used data including 8646 men and 9880 women from the National Health and Nutrition Examination Survey (NHANES) Linked Morality cohort (1999-2011) to investigate the associations of CRP and fibrinogen with mortality overall and by gender, race/ethnicity and diet quality. Cox-proportional hazard model was used to quantify the associations. With a median follow-up of 6 years, a strong dose-response relationship was observed between CRP levels and mortality risk in men after multivariable adjustment. For subjects who survived the first two years, the adjusted hazard ratios (HRs) for total mortality across quartiles (from lower to higher) of CRP were 1.97 (95% CI: 0.62-6.33), 1.89 (0.59, 6.06) and 6.34 (2.28-17.7) (P for trend <0.001). For cardiovascular disease (CVD) mortality, its association with CRP varied by diet quality. For cancer mortality, its association differed by history of cancer, and positive associations were observed only among subjects with history of cancer. In contrast, no such association of CRP with mortality was found in women. For fibrinogen, we observed its positive association with total mortality and the HRs across quartiles of fibrinogen (from lower to higher) were 1.21 (0.88, 1.67), 1.49 (1.22, 1.82) and 1.99 (1.56, 2.55). The association with CVD mortality differed by diet quality whereas no association was found with cancer mortality. Our findings suggest that higher levels of CRP and fibrinogen were associated with lower survival from total and CVD; the associations of CRP with mortality were more pronounced in men than women. Diet quality is an effect modifier for the association of CRP and fibrinogen with CVD mortality.