Influence of ABO blood groups and demographic characteristics on the prevalence of type 2 diabetes in Lagos, southwest Nigeria

Background The literature shows that ABO blood groups and demographic characteristics influence susceptibility to type 2 diabetes mellitus (T2DM) and may be used to stem the rising incidence of the disease. However, these associations vary geographically, which necessitates the need to determine the association in every locality. This study determined the ABO blood groups and demographic characteristics of 486 type 2 diabetic patients with no family history in selected hospitals in Lagos, Nigeria. Results The results showed that age class 50–59 years (35.8%) was the most susceptible to T2DM, while age class 30–39 years (8.6%) was the least. Female diabetics accounted for 56.8%, while males constituted 43.2%. Diabetes was less prevalent among singles (9.5%), while married couples had the highest prevalence (55.6%). Primary school leavers were the least diabetic (9.9%), while secondary school leavers were the most diabetic (41.6%). Approximately 59.05% of the patients were overweight, while 5.35% were underweight. Blood group O positive was the most prevalent (38.5%; p < 0.05), followed by A positive (20.2%; p < 0.05), and the least was AB negative (4.5%). Severe conditions were less common among groups O positive and A positive ( p < 0.05) compared to other blood groups. Thus, the relatively high prevalence of T2DM among blood groups O and A could be due to natural selection owing to their fitness. Conclusions ABO blood groups and demographic characteristics influenced the prevalence of T2DM in the city. Residents with blood groups O and A positive should pay special attention to T2DM.