Prediction of the cognitive impairment development in patients with autoimmune thyroiditis and hypothyroidism

Objective. The aim of the present work is to define the risk factors that can affect the presence of a cognitive impairment and analyze the associations of the brain-derived neurotrophic factor (BDNF) gene polymorphism (rs6265), vitamin D receptor (VDR) gene polymorphism (rs2228570), and N-methyl-D-aspartate (NMDA) receptor gene polymorphism (rs4880213) with the cognitive impairment in patients with autoimmune thyroiditis and hypothyroidism in the Western Ukraine population and predict the development of cognitive disorders in these patients. Methods. The study involved 153 patients with various forms of thyroid pathology (hypothyroidism, autoimmune thyroiditis, elevated serum antibodies anti-thyroglobulin and anti-thyroid peroxidase). Cognitive impairment in the examined patients was evaluated based on the results of the Mini-Mental State Examination (MMSE) test. BDNF, GRIN2B, and 25-OH Vitamin D levels in the serum of the patients and healthy individuals were quantified using highly sensitive commercial enzyme-linked immunosorbent assay kits. Genotyping of the VDR (rs2228570), BDNF (rs6265), and NMDA receptor (rs4880213) gene polymorphism was performed using TaqMan probes and Taq-Man Genotyping Master Mix (4371355) on CFX96™Real-Time PCR Detection System. Polymerase chain reaction (PCR) for TaqMan genotyping was carried out according to the kit instructions. Results. Strong direct relationship between the "Level GRIN2B" and cognitive impairments (p=0.006) was established after evaluating the complex model based on the values of the regression coefficient. An increase in the likelihood of cognitive impairment by 24.898-fold (p=0.012) was seen after assessing the effect of the CT rs6265 genotype. In addition, direct relationship between the influence of the TT rs6265 genotype and an increase in the likelihood of cognitive impairment by a factor of 21.734 (p=0.024) was also established. Conclusion. The present data indicate that the BDNF, TSH, fT4, and vitamin D levels prognostically belong to the significant indicators of the cognitive impairment development.