Association of ABO and Rh blood groups with diabetic polyneuropathy

ABO blood group antigens have been associated with various cardiovascular and inflammatory diseases; however, their relationship with peripheral nervous system disorders remains unclear. The primary aim of this study was to investigate the association between ABO and Rh blood groups and diabetic polyneuropathy in a large hospital-based population; the secondary aim was to evaluate the potential association of these blood groups with nondiabetic polyneuropathy. In this retrospective study, records of individuals with available ABO and Rh blood group data between January 2014 and December 2025 were reviewed. Participants were categorized into 3 groups: controls without peripheral neuropathy, patients with polyneuropathy without diabetes mellitus (nondiabetic polyneuropathy), and patients with diabetic polyneuropathy. A total of 21,427 individuals were included after applying the eligibility criteria and data cleaning. Blood group distributions were compared among the groups, and multinomial logistic regression analysis was performed to evaluate associations with disease status after adjustment for age, sex, and Rh factor. The study included 18,150 controls, 1697 patients with nondiabetic polyneuropathy, and 1580 patients with diabetic polyneuropathy. No significant differences were observed among the 3 groups in terms of ABO blood group distribution or Rh factor. After adjustment for age, sex, and Rh factor, no significant association was found between ABO blood groups and nondiabetic polyneuropathy. In contrast, blood group A was associated with higher odds of diabetic polyneuropathy compared with blood group O (adjusted OR 1.171, 95% CI 1.031–1.330; P = .015). The Rh factor was not significantly associated with either condition after adjustment for the available covariates. Blood group A was associated with diabetic polyneuropathy, whereas no significant association was found between ABO blood groups and nondiabetic polyneuropathy. Given the etiological heterogeneity of nondiabetic polyneuropathy and the retrospective nature of the study, these findings should be interpreted with caution and further evaluated in prospective studies with appropriate control groups and etiologically more homogeneous patient populations.