Background. According to the International Diabetes Federation, the number of people with diabetes mellitus is going to increase from 366 to 552 million by 2030. More than 1.5 million patients with diabetes are registered in Ukraine, of which 84–95 % have type 2 diabetes. Diabetic retinopathy (DR) is one of the common diabetes complications, being one of the leading causes of blindness and low vision, in particular in people of occupational age. Metabolic disorders, including activation of the polyol pathway of glucose utilization, play an important role in the pathogenesis of DR, with aldose reductase playing a key role, the activity of which is associated with the polymorphism of its gene, AKR1B1. The study of new metabolic and genetic mechanisms for the development and progression of DR in type 2 diabetes mellitus in patients from the Ukrainian population is an actual task of modern ophthalmology. Purpose: to investigate and generalize new genetically determined risk factors for diabetic retinopathy in type 2 diabetes mellitus. Materials and methods. The study involved 409 participants, who were divided into four groups: 1 — comparison cohort (98 people without diabetes mellitus type 2); 2 — 76 patients (stage I DR, without fundus changes); 3 — 64 individuals with non-proliferative DR; 4 — 64 patients with proliferative DR; control group for genetic researches included 107 ophthalmologically healthy individuals. All patients underwent blood sampling for molecular genetic research by puncture of the ulnar vein and aspiration of 2.5 ml of blood through a 23G 5.0 ml disposable syringe (Hemoplast, Etalon+, Ukraine), followed by a release into a 3.0 ml container (Vacuette K3E K3EDTA, Greiner Bio-One, Austria). Distribution of polymorphic alleles and genotypes of rs759853 and rs9640883 aldose reductase gene (AKR1B1) in patients with non-proliferative DR, proliferative DR and in the control group and their association with disease and effects on the occurrence, mechanisms of development and progression of DR were studied. Based on the conducted researches, a model of DR development prognosis was developed by construction of multiple regression with sufficient reliability of degree of influence of independent variables on a calculated indicator. Results. As a result of our research, we identified new genetically determined risk factors for the development and progression of the different stages of DR in patients with diabetes mellitus type 2, namely the role of polymorphic alleles and genotypes rs759853 and rs9640883 of the AKR1B1 gene. The developed logistic regression models found that the risk of DR incidence is five times lower in carriers of the G/G and G/A genotypes compared to carriers of the A/A genotype rs759853 polymorphism (p < 0.001). It was found that the risk is twice as high (p = 0.01) for carriers of the G/G genotype rs9640883 compared to the A/A + G/A genotypes. The risk of developing proliferative DR is 3.3 times lower in carriers of the G/G genotype and 2.5 times lower in carriers of the G/A genotype compared to carriers of the A/A genotype rs759853. Conclusions. Therefore, on the basis of our clinical, ophthalmological, molecular genetic and statistical studies we have identified new risk factors for the development and progression of different stages of DR in patients with diabetes mellitus type 2. Mathematical models of development and progression of different stages of DR in patients with diabetes type 2 were built.
Risk factors associated with diabetic retinopathy in patients with diabetes mellitus type 2
