title: Sickle cell trait and the risk of venous thromboembolism among blacks.
abstract: People with sickle cell disease have a chronically activated coagulation system and display hemostatic perturbations, but it is unknown whether they experience an increased risk of venous thromboembolism. We conducted a case-control study of venous thromboembolism that included 515 hospitalized black patients and 555 black controls obtained from medical clinics. All subjects were assayed for hemoglobin S and hemoglobin C genotypes. The prevalence of the S allele was 0.070 and 0.032 for case patients and controls, respectively (P < .001). The odds that a patient had sickle cell trait were approximately twice that of a control, indicating that the risk of venous thromboembolism is increased approximately 2-fold among blacks with sickle cell trait compared with those with the wild-type genotype (odds ratio = 1.8 with 95% confidence interval, 1.2-2.9). The odds ratio for pulmonary embolism and sickle cell trait was higher, 3.9 (2.2-6.9). The prevalence of sickle cell disease was also increased among case patients compared with controls. We conclude that sickle cell trait is a risk factor for venous thromboembolism and that the proportion of venous thromboembolism among blacks attributable to the mutation is approximately 7%.
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Harland
authors.initials: H
authors.lastname: Austin
authors.forename: Nigel S
authors.initials: NS
authors.lastname: Key
authors.forename: Jane M
authors.initials: JM
authors.lastname: Benson
authors.forename: Cathy
authors.initials: C
authors.lastname: Lally
authors.forename: Nicole F
authors.initials: NF
authors.lastname: Dowling
authors.forename: Carolyn
authors.initials: C
authors.lastname: Whitsett
authors.forename: W Craig
authors.initials: WC
authors.lastname: Hooper
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D001777:Blood Coagulation; D005838:Genotype; D006444:Hemoglobin C / Q000032:analysis / Q000235:genetics; D006451:Hemoglobin, Sickle / Q000032:analysis / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015995:Prevalence; D012307:Risk Factors; D012805:Sickle Cell Trait / Q000097:blood / Q000150:complications* / Q000235:genetics; D013923:Thromboembolism / Q000097:blood / Q000209:etiology* / Q000235:genetics; D020246:Venous Thrombosis / Q000097:blood / Q000209:etiology* / Q000235:genetics
chemical_list: D006451:Hemoglobin, Sickle; D006444:Hemoglobin C