Abstract

Ischemic stroke (IS) is a complex disease that involves genetic and environmental factors. The role of Factor XI in arterial thrombosis including IS is unclear. We have investigated the risk of IS related to Factor XI levels in a case-control study. We studied 445 individuals: 218 diagnosed with IS and 227 age-gender-ethnic control subjects. We measured Factor VIIIc, fibrinogen and Factor XIc levels. Factor XI<144% was taken as the reference group in the statistical analysis. Basic characteristic of patients and controls are summarized in the Table 1.

When we analyzed the OR in all population, we observed an interaction between dyslipidemia and high FXI levels. So, we analyzed the data in 2 subgroups, dyslipidemic and non-dyslipidemic. The crude OR of IS in dyslipidemic patients with high levels of FXI was 4.2 (95% CI:1.2–14.8) compared with dyslipidemic controls and low levels of FXI, but the OR in the non-dyslipidemic with high levels of FXI subgroup was 1.2 (95% CI: 0.4–3.2). The adjusted OR of IS in dyslipidemic patients with high levels of FXI was 6.4 (95%CI: 1.6–26.1) compared with dyslipidemic controls, but the OR in non-dyslipidemic subgroup with high levels of FXI was 0.6 (95%CI: 0.2–2.1). In conclusion, we found almost a six-fold higher risk of IS in patients with dyslipidemia and high levels of FXI. Further studies should elucidate the role of Factor XI in IS and therapeutical approaches should become apparent in regard to patients with dyslipidemia and high Factor XI plasma levels.

Table 1.

IS (n=218)n (% )Controls (n=227)n (% )Unadjusted OR (95% CI)
*Difference statistically significant (p<0.059 after adjustment by sex and age 
Sex (F/M) 104/114 108/119 NS 
Age (years, mean, range) 57 (23–80) 55(21–80) NS 
Smoking 94(45) 75(40) 1.6(1.1–2.3)* 
Dyslipidemia 91(42) 40(18) 3.4(2.2–5.2)* 
Family History of arterial thrombosis 112(51.7) 39(19) 5.1(3.3–7.8)* 
Hypertension 96(43.9) 39(17.3) 3.7(2.4–5.8)* 
Morbid Obesity 12(4.4) 6(2.6) 2.6(0.9–7.5) 
Alcohol Intake 20(9.2) 11(4.8) 1.9(0.9–4.2) 
Diabetes Mellitus 41(19) 12(5) 4.2(2.1–8.2)* 
Factor VIIIc(%, mean, range) 187.3(62–516) 157.1(48–360) p<0.0001 
Fibrinogen (g/l)(mean, range) 3.7(1.9–8.4) 3.5(2.1–7.8) p<0.002 
IS (n=218)n (% )Controls (n=227)n (% )Unadjusted OR (95% CI)
*Difference statistically significant (p<0.059 after adjustment by sex and age 
Sex (F/M) 104/114 108/119 NS 
Age (years, mean, range) 57 (23–80) 55(21–80) NS 
Smoking 94(45) 75(40) 1.6(1.1–2.3)* 
Dyslipidemia 91(42) 40(18) 3.4(2.2–5.2)* 
Family History of arterial thrombosis 112(51.7) 39(19) 5.1(3.3–7.8)* 
Hypertension 96(43.9) 39(17.3) 3.7(2.4–5.8)* 
Morbid Obesity 12(4.4) 6(2.6) 2.6(0.9–7.5) 
Alcohol Intake 20(9.2) 11(4.8) 1.9(0.9–4.2) 
Diabetes Mellitus 41(19) 12(5) 4.2(2.1–8.2)* 
Factor VIIIc(%, mean, range) 187.3(62–516) 157.1(48–360) p<0.0001 
Fibrinogen (g/l)(mean, range) 3.7(1.9–8.4) 3.5(2.1–7.8) p<0.002 

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