BLOOD PLASMA 25-HYDROXYCALCIPHEROL (25(OH)D) CONTENT IN PATIENTS WITH TYPE 2 DIABETES MELLITUS AT DIFFERENT STAGES OF DIABETIC RETINOPATHY

Abstract

Background. To date, it has become necessary to study the consequences of vitamin D-deficiency conditions on the course of severe complications of diabetes mellitus (DM), in particular diabetic retinopathy (DR), when the pleiotropic metabolic effect of vitamin D is significantly reduced. Aim: to investigate the content of 25-hydroxycalciferol (25(OH)D) in the blood plasma of patients with type 2 diabetes at various stages of diabetic retinopathy. Materials and methods. An open observational single-center one-stage selective study was conducted. The study was approved by the Local Ethics Committee. 90 patients (173 eyes) with T2D and DR (men and women; mean age - 59,4±3,4 years; mean HbA1c - 7,82±0,51 %) were assigned to 3 groups, based on the stage of DR (nonproliferative, preproliferative and proliferative). The inclusion of patients in groups with DR was carried out in accordance with the ETDRS protocol (2019). Statistical analysis was included ANOVA and regression analysis. Results. It was shown that the blood plasma concentration of 25(OH)D in patients with T2D probably decreases at each stage of DR (I stage - 19.8 [18.8-22.6] ng\ml, II stage - 16.9 ng\ml [15.3- 18.8], stage III - 14.3 [12.5-15.8] ng/ml, p<0.001). At the same time, as the stage of DR increases, the frequency of detection of 25(OH)D deficiency (concentration less than 20 ng/ml) probably increases (50.0% - stage I, 86.2% - stage II, 94.3% - stage III, p <0.001). It was shown that the risk of a high degree of DR probably decreases (p<0.001) with an increase in the concentration of 25(OH)D in blood plasma for each ng/ml (OR = 0.64 (0.53 – 0.78)). Conclusion. With an increassng in the stage of DR, the content of 25(OH)D in blood plasma decreases (p<0.001). At the same time, the proportion of patients with 25(OH)D deficiency increases, especially at stage III DR (p<0.001). An analysis of the relationship between the stage of DR and the concentration of 25(OH)D showed a decreasing in the risk of a high degree of DR with an increassng of the 25(OH)D.