Association between lipoprotein(a) and ischemic stroke: Fibrinogen as a mediator

Background Previous studies have reported lipoprotein(a) was related to increased risk of ischemic stroke. However, the role of fibrinogen in their associations was not fully elucidated. Aim We aimed to investigate the mediating role of fibrinogen in the association between lipoprotein(a) and risk of ischemic stroke. Methods A total of 516 patients with ischemic stroke were matched 1:1 to patients without ischemic stroke for age and gender. Serum lipoprotein(a) and plasma fibrinogen levels were collected on the basis of the results of biochemical tests. Multivariate conditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for lipoprotein(a) levels and ischemic stroke risk. Mediation analysis were further conducted to evaluate the potential mediating role of fibrinogen in the association between lipoprotein(a) and ischemic stroke risk. Results The lipoprotein(a) level of subjects with ischemic stroke was significantly higher than that of subjects without ischemic stroke (P < 0.001). Each SD increment of lipoprotein(a) was associated with 27% higher odds (OR 1.27, 95%CI: 1.11, 1.45) increment in ORs of ischemic stroke. Furthermore, mediation analyses indicated that fibrinogen mediated 10.15% of the associations between lipoprotein(a) and ischemic stroke. Conclusions Higher level of lipoprotein(a) was independently associated with increased risk of ischemic stroke and fibrinogen partially mediated the associations of lipoprotein(a) and ischemic stroke risk.