The role of cholecalciferol deficiency in the development of latent autoimmune diabetes in adults

Background. Recently, a lot of information has appeared on the role of cholecalciferol deficiency in the development of the mechanisms of classical types of diabetes mellitus (DM) and its complications. However, there are currently almost no data regarding latent autoimmune diabetes in adults (LADA). The purpose of this study was to determine the effect of vitamin D deficiency on the compensation of carbohydrate metabolism in LADA. Materials and methods. The study included 56 patients with DM: 34 with LADA and 22 with classical type 1 DM (DM1), as well as 20 practically healthy individuals of the control group. According to the main phenotypes, patients with LADA were divided into 2 groups: LADA1 and LADA2. Cholecalciferol status was determined by the immunochemiluminescence method. Results. The fasting blood glucose level in LADA and DM1 group was significantly higher than in the controls, by 63.9 and 91.1 % (p < 0.001), respectively, and was also 16.6 % higher when comparing DM1/LADA groups (p < 0.05). The level of HbA1c in 66.1 % of patients of the experimental groups was more than 7 %, which indicates insufficient compensation of the disease. The content of vitamin D was significantly lower in the experimental groups compared to the controls; when comparing LADA/DM1 — by 43.7 % lower in case of classical DM1 (p < 0.05). Compensation of carbohydrate metabolism is worse in patients with LADA1 than in LADA2, and the lowest level of vitamin D was recorded in LADA1. According to the linear regression analysis of correlations in patients with LADA, negative correlations of medium strength were recorded between the level of cholecalciferol and fasting blood glucose (r = 0.487; p < 0.05), HbA1c (r = –0.593; p < 0.05); positive — between cholecalciferol and C-peptide (r = 0.412; p < 0.05). Conclusions. In patients with autoimmune diabetes, there is an insufficient supply of cholecalciferol. Low cholecalciferol content is observed in both groups of patients with LADA regardless of the disease phenotype and is associated with worse compensation of DM.