Polymorphism of the endothelial nitric oxide synthase gene is associated with diabetic retinopathy in a cohort of West Africans

Purpose: In addition to chronic hyperglycemia, there is increasing evidence that genetic factors may be important in the development of diabetes retinopathy (DR). Specifically, polymorphisms of the endothelial nitric oxide synthase gene (eNOS) have been reported to be associated with multiple health conditions including DR, hypertension, nephropathy, and cardiovascular diseases in several ethnic groups. However, there is a paucity of similar data in African Americans and other African populations. To address this issue, we investigated the potential association between polymorphisms of the eNOS gene and diabetes-related phenotypes in 384 persons with type 2 diabetes and 191 controls from two West African countries (Ghana and Nigeria). Methods: We genotyped the deletion/insertion (4a/b) and the G894T polymorphisms of eNOS gene in a total of 575 persons. Results: The b/b genotype of the polymorphism was associated with a 2.4 fold increased risk of DR (95% CI 1.39-4.09). In contrast, we did not observe any association between the genotypes or alleles of G894T polymorphism with DR, hypertension, or nephropathy. Conclusions: We observed a significant association between the 4a/b polymorphism of the eNOS and DR in our West African cohort.