Prospective study of ABO blood type and the risk of pulmonary embolism in two large cohort studies

Abstract

Prior studies have suggested an association of ABO blood type and the risk of venous thromboembolism however, most studies were retrospective and lacked important covariates or validated endpoints More over risk estimates varied widely across studies Therefore we prospectively examined the association of blood type and the risk of incident pulmonary embolism (PE) in two large cohort studies, the Nurses' Health Study and Health Professionals Follow up Study During 1,010 378 person years of follow up among 77,025 women and 30 105 men 499 participants developed PE Compared to those with 0 blood type participants with non 0 blood type had multivariable adjusted hazard ratios (HR) of 1 86 (95% CI, 1 35-2 57) for idiopathic PE, 1129 (95% CI, 1 03-1 62) for non idiopathic PE and 1 46 (95% CI 1 22-1 76) for any PE Hazard ratios were similar for participants with blood types A, B, and AB Age adjusted absolute rates of idiopathic PE over 10 years of follow up differed by blood type 0 11% for 0, 0 20 701 for A 0 19% for AB, and 0 21% for B For idiopathic PE, the population attributable fraction was 33% for inheritance of non 0 blood type Among past and current smokers, participants with non 0 vs 0 blood type had a HR for idiopathic PE of 256 (95% CI, 1 61-4 08) Among never smokers the HR for idiopathic PE was 1 30 (95% CI 0 82-2 05 P(interaction)=0 04) In two large, prospective cohorts ABO blood type was significantly associated with the risk of idiopathic and non idiopathic PE, with even greater risk for idiopathic PE among current and past smokers with non O blood type