Risk factors for venous thrombosis in the black population.
Risk factors for venous thrombo-embolism (VTE) in the black population are poorly characterized. Of 142 black cases tested a genetic cause was identified in only 9.1%: 4.2% had protein C deficiency, 2.8% protein S deficiency, 0.7% antithrombin deficiency and 1.4% were heterozygous for FV Leiden. We hypothesised that elevated factor VIII levels constitute a candidate risk factor for venous thrombosis in the black population. Factor VIII (FVIII:C) levels were determined in 100 black patients with VTE and 100 black controls in a case-control study. Of the patients 34% had a FVIII:C above 228 IU/dL (the 90th centile value in normal blacks) compared to 10% controls. Relative to those with FVIII:C below this value, odds ratio (OR) for risk of VTE was 4.64 (95% CI 2.02-10.85). When FVIII:C below 150 IU/dL was used as a comparator, OR was 11.1 (95% CI 4.29-29.43). There was evidence for a dose-response relationship. We propose that raised FVIII:C is a major risk factor for VTE in black subjects with prevalence and odds ratio exceeding those reported for white subjects.
Patel
Raj K
RK
Department of Haematological Medicine, King's College Hospital, Denmark Hill, London SE5 9RS, United Kingdom.
Ford
Elizabeth
E
Thumpston
Jill
J
Arya
Roopen
R
D000328:Adult; D044383:Black People; D016022:Case-Control Studies; D005165:Factor V; D005169:Factor VIII / Q000032:analysis* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D020151:Protein C Deficiency; D018455:Protein S Deficiency; D012307:Risk Factors; D020246:Venous Thrombosis / Q000208:ethnology / Q000209:etiology*
C095381:factor V Leiden; D005165:Factor V; D005169:Factor VIII