BACKGROUND The association between antigens A and B and cardiovascular disease is still unclear. Several reports have suggested an important involvement of the ABO blood group system in the susceptibility to thrombosis. Assessing that non-O blood groups in particular A blood group confer a higher risk of venous and arterial thrombosis than group O. Epidemiologic data are typically not available for all racial and ethnics groups. The purpose of this observational study was to identify a probable link between ABO blood group and ischemic and non-ischemic disease in subjects from the province of Casablanca, Morocco and to analyze whether A blood group individuals were at higher risk of ischemic disease or not. METHOD An observational study had been conducted from the beginning of 2017 until the end of 2019 in the Department of Cardiology, University Hospital Centre, Ibn Rochd, Casablanca, Morocco. We recruited consecutive subjects (549 men and 544 woman) at our center between 2017 and 2019. We studied data on age, gender, past history of hypertension, diabetes, smoking, sedentarism, obesity, hyperlipidemia, use of estrogen-progestin contraceptives and blood group distribution. Their ABO blood groups were determined using standard agglutination techniques. In each blood group type, we evaluated the prevalence of ischemic and non-ischemic cardiovascular disease. RESULT Of the 1093 patients whose medical records were reviewed, 482 (44.1%) were carrying blood group A. Of the remaining 611 patients, 353 (32.3%) had blood group O, 212 (19.4%) blood group B, and 46 (4.3%) blood group AB. The diagnosis of ischemic disease (ID) was higher in patients with blood group O (63.3%) than in other blood groups, and the diagnosis of valvular disease was higher in patients with blood group A (48.7%) compared to other groups. In patients with blood group B or AB compared to non-B or non-AB, respectively there was no statistically significant difference in ID incidence. The incidence of ID in men was significantly higher in blood group O (63.2%, p = 0.015) compared with women, while there valvular disease was a statistically higher in women (54.5%, p = 0.035). This difference remains statistically significant after adjustment for common cardiovascular risk factors. CONCLUSION Our study suggests an association between ABO blood group and Ischemic disease and non-ischemic disease in Moroccan population. In African countries, where most of health facilities are understaffed, more rigorous studies with a larger population are needed to give high level of evidence to confirm this association in order to establish the need to be more aggressive in risk factor control in these individuals.
A Retrospective Observational Study Comparing ABO Blood Group and Rh Factor Distribution in Patients with Rheumatic Diseases and Healthy Donors in Southern India
