ABO blood types associated with the risk of venous thromboembolism in Han Chinese people: A hospital-based study of 200,000 patients

ABO blood types are putatively associated with the risk of venous thromboembolism (VTE), but it is not proved in Chinese people. A large population of Han Chinese patients discharged from Peking Union Medical College Hospital between January 2010 and June 2016 were retrospectively analyzed in a case-control study. A total of 1412 VTE patients were identified from 200,660 discharged Han Chinese patients, including 600 patients with deep vein thrombosis (DVT), 441 patients with pulmonary embolism, and 371 patients with both DVT and pulmonary embolism. The prevalence of non-O blood type was weakly but statistically higher in VTE patients compared with 199,248 non-VTE patients, with an odds ratio (OR) of 1.362 (95% confidence interval [CI], 1.205-1.540). Subgroup analysis showed that the OR for non-O blood type was still increased. It was greater in pre-hospital VTE (OR = 1.464) than that in hospital-acquired VTE (OR = 1.224), and greater in unprovoked VTE (OR = 1.859) than that in provoked VTE (OR = 1.227). The OR for non-O blood type decreased with age in subgroup analysis. These results suggest a weak but statistically significant correlation between non-O blood type and risk of VTE in Han Chinese people.