Association between Abo Blood Groups and Periodontal Disease Severity: A Cross-Sectional Study

Abstract

Introduction: Periodontal diseases represent a spectrum of inflammatory conditions affecting tooth-supporting structures, with multifactorial etiology involving microbial, genetic, environmental, and host factors. The ABO blood group system consists of genetically determined antigens present on red blood cell membranes and various tissues, potentially influencing disease susceptibility through immunological mechanisms. Despite significant advances in understanding periodontal pathogenesis, the role of genetic predisposition, particularly blood group antigens, remains an area of active investigation with conflicting research findings.

Objectives: To investigate the association between ABO blood group phenotypes and periodontal disease severity in a South Indian population, and to establish any significant correlations between blood group distribution and clinical periodontal parameters.

Methods: A cross-sectional observational study was conducted among 647 systemically healthy individuals aged 18-60 years attending the Department of Periodontics. Participants were categorized based on ABO blood groups and Rh factor using standard agglutination techniques. Periodontal status was comprehensively assessed using Plaque Index, Gingival Index, Probing Pocket Depth, and Clinical Attachment Level at six sites per tooth. Participants were classified into three groups: mild gingivitis, moderate gingivitis, and periodontitis. Statistical analysis was performed using chi-square tests and ANOVA with significance set at p<0.05.

Results: Blood group O was most prevalent (57.7%), followed by B (23.1%), A (13.8%), and AB (2.3%). Rh-positive individuals constituted 96.9% of the sample. Moderate gingivitis was observed in 35.4% participants, mild gingivitis in 40.0%, and periodontitis in 24.6%. Blood group A showed higher prevalence in gingivitis groups (35.9% mild, 34.8% moderate), while blood group O demonstrated increased association with periodontitis (23.6%). Mean periodontal parameters showed no significant differences across blood groups. Chi-square analysis revealed no statistically significant association between ABO blood groups and periodontal disease severity (χ²=7.342, p=0.290). Age was significantly associated with periodontal status (p<0.001), while gender and Rh factor showed no association.

Conclusions: This large-scale study found no statistically significant association between ABO blood group phenotypes and periodontal disease severity in a South Indian population. While observational trends suggested blood group A individuals might have higher gingivitis prevalence and blood group O individuals showing increased periodontitis occurrence, these observations did not reach statistical significance. The findings suggest that ABO blood group phenotypes may not serve as reliable predictors of periodontal disease susceptibility in isolation.