A study of 666 people in Riyadh found that blood group B was associated with higher odds of type 2 diabetes, while group O was linked to lower odds, although the findings do not establish causation.
A Saudi study published in BMC Endocrine Disorders has added to evidence that inherited blood type may be linked to type 2 diabetes, with researchers at King Abdulaziz Medical City in Riyadh reporting that blood group B was associated with higher odds of the disease and blood group O with lower odds. The findings come from an analysis of 666 people, including 350 patients with type 2 diabetes and 316 healthy blood donors used as a comparison group.
Type 2 diabetes remains the dominant form of diabetes worldwide and is driven largely by insulin resistance and the gradual failure of insulin-producing cells in the pancreas. In Saudi Arabia, where the condition is common, scientists have increasingly examined whether genetic traits beyond weight, diet and activity levels may help explain who develops the disease. The new paper focuses on the ABO and Rhesus blood group systems, which are best known for transfusion compatibility but have also been studied in relation to clotting, cardiovascular disease and some cancers.
The Riyadh team carried out a cross-sectional review of records collected between January 2019 and December 2023. After comparing blood group frequencies between the two groups and adjusting for potential confounders, the researchers found a statistically significant difference in ABO distribution. Blood groups A, B and AB were more common among patients with diabetes, while group O appeared more frequently among controls. In the adjusted analysis, blood group B was linked with increased odds of type 2 diabetes and blood group O with reduced odds. The Rhesus factor was not associated with diabetes in this cohort.
The results fit a broader but uneven body of research. A 2022 systematic review and meta-analysis found that blood group B was associated with greater risk of type 2 diabetes and blood group O with lower risk. But not all studies have agreed. Earlier work using the E3N cohort reported higher risk for people with blood groups A and B compared with those with group O, while other studies have also pointed to blood group B as a possible risk marker. That inconsistency suggests any biological effect is likely modest and may vary by population.
The Saudi paper does not establish causation. Because it was cross-sectional, it cannot show that blood type influences the later development of diabetes, only that the two were associated in this sample. The use of healthy blood donors as controls may also limit how far the findings can be generalised, and the authors acknowledged that unmeasured factors such as body mass index, family history and lifestyle may still have influenced the results. Even so, the study adds to an emerging picture in which a routine laboratory trait could one day contribute to broader diabetes risk assessment if larger prospective studies confirm the signal.
For now, the practical message remains unchanged: established measures such as weight control, physical activity and blood glucose monitoring remain the best-supported ways to prevent or delay type 2 diabetes. Blood type is not something people can alter, but if future research strengthens the case for a real link, it may help sharpen risk models alongside better-known metabolic and lifestyle factors.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
