Relationship of ABO Blood Type on Rotator Cuff Tears

BackgroundABO blood groups are associated with various diseases. A relationship between Achilles tendon ruptures and blood type O has been reported, although its pathogenesis was not clear. To the best of our knowledge, there is no published study describing the relationship between blood type and rotator cuff tendon tears.ObjectiveTo determine whether patients with rotator cuff tear had a greater prevalence of blood type O than those without rotator cuff tear.DesignA cross-sectional study.SettingResearch hospital outpatient evaluation.ParticipantsA total of 316 subjects with shoulder pain were included and divided into “tear” and “no-tear” groups according to ultrasonographic examination.Main Outcome MeasuresABO blood group, gender, dominant arm, smoking history, trauma history, and age were compared between the 2 groups and the odds ratios of these factors were evaluated by logistic regression.ResultsThe tear group (38.6%) had more instances of blood type O than the healthy population (27.2%; P = .002). The adjusted odds ratio for rotator cuff tear for blood type O to non-O was 2.38 (95% confidence interval 1.28-4.42). The odds ratios for rotator cuff tears for smoking, major trauma history, minor trauma history, and age were 2.08, 3.11, 2.29, and 1.06, respectively.ConclusionPatients with rotator cuff tears were more likely to have blood type O. The odds ratios of factors for rotator cuff tears were high in the following order: major trauma history, blood type O, minor trauma history, and age.