Independent prediction of metabolic syndrome by plasma fibrinogen in men, and predictors of elevated levels

Abstract 

The role of plasma fibrinogen levels in predicting metabolic syndrome (MetS) and assessment of determinants of these levels were investigated. A total of 2234 men and women, aged 49±12 years, representative of Turkish adults who had plasma fibrinogen determinations, were prospectively evaluated and followed for a mean of 6.6 years. The modified Clauss method was used for assays. MetS was defined by ATPIII criteria modified for male abdominal obesity. MetS cases at baseline were excluded in prospective analyses.

Median (interquartile range) fibrinogen values were 2.87 (2.29; 3.56) g/L. Fibrinogen levels predicted significantly newly developing MetS in men (RR 1.40 [95%CI 1.07; 1.83] for a 2-fold increment), after adjustment for age and smoking status, and (RR 1.32 [95%CI 0.95; 1.83] again for doubling), after additional adjustment for all 5 components of MetS. MetS was not significantly predicted by fibrinogen levels in women in either multivariable model. By regression analysis of eight covariates, not waist circumference, but systolic blood pressure, current smoking and C-reactive protein (CRP) in men, and age in women were predictors of elevated (>3.0 g/L) fibrinogen at follow-up (p<0.05 in all).

Conclusions

Plasma fibrinogen predicts MetS independently of its components in men, in contradistinction to women, and, hence, is likely one of its components. Hyperfibrinogenemia representing an inflammatory state is postulated as the underlying mechanism. Central obesity is linked to elevation in fibrinogen mainly through the mediation of blood pressure, CRP, and via being affected by cigarette smoking.

Keywords: Central obesity, Fibrinogen, Hypertension, Inflammatory state, Insulin resistance, Metabolic syndrome