ANTIOXIDANT STATUS OF THE ORGANISM BY THE LEVEL OF CATALASE IN PATIENTS WITH AUTOIMMUNE THYROID DISEASE

Abstract

Oxidative stress is known to play a significant role in the pathogenesis of autoimmune thyroid diseases. Catalase (CAT) is an important component of antioxidant defense because it breaks down hydrogen peroxide, which can accumulate in cells as a metabolic byproduct and lead to damage to cellular structures. The aim of the study was to assess the antioxidant status of the body based on the levels of catalase activity in blood plasma and erythrocytes of patients with autoimmune thyroid disease, taking into account gender.
Materials and methods. In the clinic of the SI «V. Danilevsky Institute for Endocrine Pathology Problems of the NAMS of Ukraine», Kharkiv, 175 patients with thyroid pathology (90 with diffuse toxic goiter (DTG) and 85 with autoimmune thyroiditis (AIT)) were examined, who were divided into subgroups by gender. Among patients with DTG aged 31–73 years (49.66 ± 1.81), there were 31 men aged 47.45 ± 2.5 years and 59 women aged 51.0 ± 2.48 years. In the group of patients with AIT aged 30–71 years (51.11 ± 1.90), there were 13 men aged 45.53 ± 2.5 years and 72 women aged 50.21 ± 3.74 years. The control group consisted of 22 individuals without thyroid pathology aged 53.77 ± 2.30 years (10 men and 12 women). In patients, the activity of CAT was determined by the photometric method in blood plasma (p-CAT) and erythrocytes (e-CAT), which can be used to assess the antioxidant status of the body and detect disorders in the system of protection against free radicals. Statistical processing of the obtained data was carried out by methods of variational statistics using the standard package StatSoft STATISTICA 10. The probability of differences in mean values was determined using the Student's t-test; differences were considered statistically significant at P < 0.05.
Results. In the total group of examined patients with autoimmune thyroid pathology the activity of p-CAT and e-CAT significantly exceeded the levels of the control group. When analyzing catalase activity according to autoimmune thyroid disease, it was found that in patients with DTG, the activity of both p-CAT and e-CAT was significantly higher compared to patients with AIT (P < 0.01; P < 0.001, respectively). Analysis of the gender characteristics of CAT activity proved that in men with DTG, its activity was lower compared to the data in the group with AIT. Conversely, in women with DTG, the activity of CAT was higher than in the group with AIT. At the same time, the data of p-CAT and e-CAT in men both on the background of DTG and on the background of AIT significantly exceeded the corresponding data obtained in women.
Conclusions. In patients with autoimmune thyroid pathology, there is a probable increase in catalase activity in both blood plasma and erythrocytes. The degree of catalase activation in autoimmune thyroid patho­logy has gender characteristics: among men, higher catalase activity is found in autoimmune thyroiditis, and among women, in diffuse toxic goiter.