The result might seem surprising, since type 2 diabetes is highly prevalent and O is the most common blood type….
However, Dr. Guy Fagherazzi added that, “Our work has been based on previous findings regarding stroke, where people with the O blood group had a lower risk of developing the disease. The suggested mechanisms could also be involved with type 2 diabetes.”
The findings come from an analysis of 82,104 female teachers participating in a French prospective cohort study initiated in 1990 to study risk factors for chronic diseases.
This is the first study to investigate a relationship between blood type and type 2 diabetes risk using such a large cohort size and a prospective design. Therefore, “it is a bit early to have strong recommendations for clinicians.
Dr. Fagherazzi said, nonetheless, “We can suggest to clinicians and epidemiologists who are working on type 2 diabetes to include blood type in their studies as a potential risk factor. It could be also included in individual risk scores of diabetes.”
The investigators conducted three separate analyses using type O, Rhesus-factor–positive blood group, and type O-negative (universal donor) as references.
Mean follow-up was 13 years for the total 3553 type 2 diabetes cases and 16 years for non-diabetes cases. Results were adjusted for family history of diabetes, education level, physical activity, hypertension, smoking, and body mass index.
Compared with type O, those with either blood group A or B had a significantly greater risk for type 2 diabetes, with hazard ratios (HRs) of 1.10 and 1.21, respectively. The risk for type AB was also higher (HR, 1.17) but did not reach statistical significance. There was no difference overall in diabetes risk by Rhesus-group positive or negative (HR, 0.96).
However, when compared with O-negative, the highest risk was seen in the women with blood type B-positive, with a hazard ratio of 1.35. Types AB-positive, A-positive, and A-negative also were associated with greater risk compared with O-negative, with HRs of 1.26, 1.17, and 1.22, respectively.
The authors say it’s not clear why there are associations between blood type and diabetes, but they list three possibilities.
First, the human ABO locus might influence endothelial or inflammation markers, such as the factor VIII/von Willebrand factor complex, which is present in higher levels in non-O individuals.
Second, there may be a relationship between blood groups and levels of plasma soluble intercellular adhesion molecule 1 (sICAM-1) and/or tumor necrosis factor-receptor 2 (TNF-R2), both of which have been linked to an increased type 2 diabetes risk.
Third, a recent paper suggested that blood group “is one of the genetically determined host factors that modulate the composition of the intestinal microbiota, which participates in metabolism by affecting the energy balance, glucose metabolism, and low-grade inflammation,” the researchers observe.
“Our findings rely on a very large prospective cohort study, and our results are really encouraging for a better understanding of type 2 diabetes. The evolution of the epidemic of type 2 diabetes is dramatic, and there is a need to find new risk factors. This will ultimately lead to better prevention and better targeted treatment.”
- People with blood type O are less likely to develop type 2 diabetes.
- The highest risk was seen in the women with blood type B-positive, Types AB-positive, A-positive, and A-negative also were associated with greater risk compared with O-negative
Guy Fagherazzi. People with blood groups A, B and AB at higher risk of type 2 diabetes than group O, Diabetologia. Published online December 18, 2014