Factor XII Concentrations and Risk of Intracerebral Haemorrhage. A Prospective Case-Referent Study

Abstract Objectives In a previous pilot study, we found an association between high factor XII levels and risk of haemorrhagic stroke suggesting that factor XII is a risk marker for intracerebral haemorrhage (ICH). The aim of this study was to further investigate the association between factor XII and risk of ICH in a larger population. Materials and Methods This study was conducted as a prospective nested case-referent study. All participants underwent a health examination and blood sampling for factor XII analysis at baseline. Cases were defined as participants who were diagnosed with a first-ever ICH between 1985 and 2000. Two referents were matched to each case. Results We identified 70 individuals with first-ever ICH and 137 matched referents who had undergone a health examination and donated blood samples before the ICH event. The mean age was 54 years, and 33% were women. The median time-to-event was 3.5 years (range 0.04 to 10.2 years). Conditional logistic regression showed no association between factor XII and risk of ICH, (odds ratio 1.06 per SD; [95% confidence interval: 0.57–1.97] in a multivariable model). Conclusions A previous finding of an association between high concentration of factor XII and risk of ICH could not be replicated in this larger study.