Environmental arsenic exposure and its toxicological effect on thyroid function: a systematic review

Objectives This study was performed to review epidemiological evidence related to Arsenic (As) effects on the thyroid function by focusing on the serum thyroid hormone concentration. Content As, one of the main pollutants, has been recognized as an endocrine-disrupting agent that may affect the function of thyroid as shown by experimental studies. Summary This systematic study indicates the association between As exposure and thyroid dysfunction. The studies have shown an association between serum and urine concentration of arsenic and thyroid dysfunction. Most of them reported the association between increase in the serum or urine As levels and decrease in the triiodothyronine (T3) and thyroxine (T4), and also elevation in the thyrotropic hormone (TSH) levels. Outlook Our findings related to the effects of As on the function of thyroid in humans are still limited and future studies should be done to address this question.

ASSOСIATION BETWEEN VITAMIN D STATUS AND METABOLIC DISORDERS IN PREMENOPAUSAL WOMEN WITH AUTOIMMUNE HYPOTHYROID DISEASE

The aim: Is to establish a relationship between serum vitamin D level with carbohydrate and lipid indexes in women with autoimmune hypothyroid disease. Materials and methods: 146 women with autoimmune hypothyroid disease were examined in the period 2017-2019, who signed the informed consent. The mean age of women was 43.8 ± 0.7 years. Anthropometric, general clinical and biochemical examinations were performed including determination of lipid metabolism, hydrocarbon metabolism and establishment of vitamin-D status. Results: Vitamin D deficiency was found in 78.8%, insufficiency in 17.1% of women with autoimmune hypothyroidism. Statistical processing of results was carried out and established strong negative correlation between 25 (OH) D and Thyroid Peroxidase Antibody (r = -0,77) and thyrotropic hormone level (r = -0.72), р<0,05. Strong inverse correlations were found between vitamin D levels and body mass index (r=-0,74) and total cholesterol levels (r=-0,72), negative correlation of medium strength was with highdensity lipoprotein cholesterol (r=-0,58), triglycerides (r=-0,46), atherogenic coefficient (r=-0,65) and the HOMA-IR (r=-0,57), The values of p < 0.05 were considered reliable. Conclusions: The incidence of vitamin D hypovitaminosis in women with autoimmune thyroid disease is significantly higher than in the healthy population. Low vitamin D status is significantly associated with autoimmune thyroid dysfunction and determines the degree of metabolic disorders and cardiovascular risk in premenopausal women with autoimmune hypothyroid disease.

The reaction of the thyroid gland to the thyrotropic hormone “load” in high and low-yielding cows

The studies were carried out on cows of Holstein black-and-white breed. 2 groups of 10 heads each were formed. The milk yield for lactation was 10 thousand kg in the first group, and - 5 thousand kg in the second group. Blood was collected from the subcaudal vein monthly during lactation. T3 and T4 were determined in the blood serum. The functional “load” on the thyroid gland was performed at the peak of lactation (3 months) and at its end - at 9 months. The TSH preparation at a dose of 0.5 u/kg of live weight was administered intramuscularly on an empty stomach before morning feeding. T3 and T4 hormones in the blood were determined before the injection of TSH and 0.5 one and two hours after the injection. Kath was calculated using the formula Т1 – Т0 / Т0 where Kath is the coefficient of activity of thyroid hormones. T0 – T3 and T4 levels before TSH injection T1 – T3 and T4 levels 2 hours after TSH injection. During lactation, the level of milk production and thyroid hormones varies inversely with the average daily milk yield. During the period of high milk productivity (2,3,4 months of lactation), the concentration of T3 and T4 in both groups was low, and later increased and was maximum in the 8th month of lactation. The functional reserves of the thyroid gland in high-yielding cows in 3 and 9 months of lactation are lower in relation to low-yielding cows.

State of the coronary arteries and assessment of the role of hormone replacement therapy in patients with coronary heart disease against the background of primary manifest hypothyroidism

Aim To study features of coronary damage and incidence of different types of acute coronary syndrome (ACS) in history associated with primary symptomatic hypothyroidism in patients with ischemic heart disease (IHD) and possible associations of replacement hormonal therapy with lipidogram indexes.Material and methods This retrospective study included 344 patients with IHD and functional class I-III stable angina (ССS, 1976). Of them 100 patients had primary symptomatic hypothyroidism and 244 had no hypothyroidism. Coronary angiography was performed for all patients included into this study. Routine laboratory, instrumental and clinical indexes were analyzed. Hypothyroidism was confirmed by levels of thyrotropic hormone, free triiodothyronine, and thyroxine. Comparative analysis was performed for the incidence of ACS types in history, types of coronary injury, and laboratory, instrumental and clinical indexes with assessment of potential interrelations. Statistically significant results were reported. Type of data distribution was evaluated with the Kolmogorov-Smirnov test. Quantitative data with normal (Gaussian) distribution were presented as mean (M) and standard deviation (SD). Data with attributes of non-normal distribution were presented as median (Me) with maximum and minimum values (min; max). Statistical significance of differences between means was assessed with the Mann-Whitney test. Logistic regression analysis was used in parallel for evaluating dependence of a quantitative variable on values of two or more quantitative or qualitative variables (factors). Significance level for testing of statistical hypotheses was р<0.05.Results Incidence of ST segment elevation ACS (STEACS) was significantly higher in IHD patients with hypothyroidism than in the group without hypothyroidism (61.6 and 35.6 %, р=0.03) and also with three-vessel coronary artery disease (60.6 and 30.6 %, р=0.001). In the IHD group with hypothyroidism, levels of total cholesterol, triglycerides, and low- and very low-density lipoproteins were significantly increased compared to the respective values in patients without hypothyroidism (р<0.0001). An inverse correlation was found between lipidogram indexes and L-thyroxine (р<0.0001).Conclusion The incidence of STEACS associated with primary symptomatic hypothyroidism in history was significantly higher in the patient group with IHD on the background of primary symptomatic hypothyroidism compared to the comparison group. Also, the incidence of three-vessel coronary disease was significantly greater than in the IHD patient group without hypothyroidism. A significant association was found between the replacement hormonal therapy and the best lipidogram indexes. The authors suggested that the key factor for prevention of adverse cardiovascular events in IHD with hypothyroidism is achieving control of clinical manifestations of hypothyroidism with replacement hormonal therapy.

INDICATORS OF THYROTROPIC HORMONE IN PARKINSON'S DISEASE

The article presents the data of our studies on ТSH in patients with Parkinson's disease (PD): their characteristics, features of clinical manifestations

Influence of radiating and chemical loads on changes of biochemical indices of the endocrine homeostasis in inhabitants from ecologically various areas of the Bryansk region

There ecologic-hygienic ranging of all 27 areas of the Bryansk region was performed with the using of the innovative methodical approach with taking into account the integrated indices of total pollution of all objects of the environment. The analysis of results of the performed biochemical researches with studying of indices of the endocrine homeostasis in residents of ecologically various areas has allowed to evolve thyrotropic hormone TTH (Qcalc=2,4 at K=1,96) and thyroid hormone ST4 (Qcalc=3,684 at K=1,96) as biological markers of the negative impact of technogenic-chemical contamination of environment on human health.

About the possible role of the hypocaloric diet in the pathogenesis of hypothyroidism

Many researchers of the thyroid pathology consider that the investigation of the epidemiology of thyroid disease in conjunction with the study of the diet are relevant. The question is if the unbalanced diet may worsen the course of hypothyroidism. The purpose of this study was to establish the relationship between the peculiarities of the diet of patients with hypothyroidism and the functional state of the thyroid gland. Methods and materials. It was observed 400 women of Polish nationality aged 19–28 years living in Biala Podlaska district of the Lublin Voivodeship of Poland which consider themselves healthy. The blood levels of free (FT3) and total (T3) triiodothyronine, free (FT4) and total (T4) thyroxin, thyrotropic hormone (TSH) were determined. With the help of questionnaires and food tables, the approximate average amount of proteins, fats and carbohydrates in the daily ration was determined, as well as the average amount consumed daily with iodine. The prevalence of hypothyroidism among surveyed women was 3.5 % and was not significantly different from the values ​​observed in the European Union. Women with reduced thyroid function consumed with food significantly 3.78 times less iodine, 2.97 times (P < 0.001) less salt and 1.47 times (P < 0.001) less protein compared to women with normal thyroid function. In addition, women with hypothyroidism consumed with food 2.25 times (P < 0.001) more products with properties of strumogens. The development of hypothyroidism in the examined women was combined with a reduced intake of iodine and proteins with food products and an increased use of products with the properties of strumogens.