The interaction between lipid exchange and thyroid status in the conditions of prolonged influence of small doses of radiation

Abstract

We studied the interaction between the indicators of lipid exchange and thyroid status among the inhabitants of radiation contaminated territories under additional psycho-emotional load. We observed 170 students aged between 18–24 and divided them into a control group of students who were from areas unaffected by radiation (70 people) and the main experimental group of students from territories of increased radio-ecological load (IV radiation zone, 100 people). We determined the content of thyrotropic hormone (TTH), triiodothyronine (T3), thyroxin (T4), total cholesterin (TC), triglycerides (TG), cholesterin of lipoproteins of high density (Ch-LPHD) and cholesterin of lipoproteins of low density (Ch-LPLD). We found that people who had lived since birth in territories which were contaminated with radionuclides and were affected by prolonged influence of small doses of ionizing radiation had significant fluctuations of indicators of concentrations of TTH, T3 and T4, forming manifestations of hypothyroidism and hyperthyrosis among some of those tested. Independently from hyperthyrosis, the effect was accompanied by growth in the level of TH, TG, Ch-LPHD and Ch-LPLD. Persons with manifestations of hypothyroidism had the content of TH above the upper limit of the homeostatic norm and the level of Ch-LPLD was higher than the norm in sub-groups with features of hypo- and hyperthyrosis. All those tested from the main group showed a significant positive correlation connection between the level of TTH and levels of TH and Ch-LPLD. The subgroup with manifestations of hyperthyrosis had a positive correlation between the levels of TTH and TG, the subgroups with manifestations of euthyroidism and hyperthyrosis had a negative correlation between the levels of TTH and Ch-LPHD. The hyperthyrosis subgroup had a significant positive correlation connection between T3 and TH and Ch-LPLD. The euthyroidism and hypothyroidism subgroups had a significant negative correlation between T3 concentration and Ch-LPLD. The cortisol indicator positively correlated with levels of TH and Ch-LPLD in all subgroups divided according to thyroid status. In the conditions of additional psycho-emotional load (examinations), those tested had an increased level of TP (higher than the norm in the subgroups of hyperthyrosis and hypothyroidism) caused by the increase in cortisol level and a tendency of decrease in TTH. At the same time, the level of Ch-LPLD increased (higher than the upper norm) as a result of decrease in the content of Ch-LPHL. The coefficient of correlation between the level of TTH and levels of TH and Ch-LPLD lost statistical significance in all subgroups divided according to thyroid status. In the hyperthyrosis subgroup, the effect of loss of correlation with TH and Ch-LPLD was also observed for T3. Thus, the individuals tested from territories polluted by radionuclides, had proaterogenic changes dependant on thyroid status,which can become a precondition for the development of metabolic syndrome. The risk of dyslipidemia increases in the conditions of additional psycho-emotional load, when the regulatory effect of the thyroid gland`s hormones is reduced.

Interdependence of oxidative/antioxidant system indicators and thyroid status under conditions of prolonged exposure to small doses of radiation

“…The level of LDL-C inversely correlated with the level of triiodothyronine; in the subgroup of hyperthyroidism, this correlation was positive. In all three subgroups, a statistically significant correlation between the level of LDL-C and the level of oxidative processes stimulator TSH (Sokolenko & Sokolenko, 2017), was noted. Thus, thyroid status had a significant effect on the lipid metabolism of the examined patients, although its role was leveled to some extent in conditions of emotional stress.…”

“…We have shown that the inhabitants of the territory of enhanced radioecological control demonstrated a certain tension of the thyroid system, which was characterized by high TSH concentration in people with a high T 3 level in peripheral blood. The thyroid status correlated with lipid parameters (Sokolenko & Sokolenko, 2017). Also, in this cohort radiation-induced intensification of oxidative processes was detected, which grew under conditions of additional stress of emotional nature and influenced the immune system (Sokolenko et al, 2018).…”

Interconnection of the immune system and the intensity of the oxidative processes under conditions of prolonged exposure to small doses of radiation

“…In our previous studies, typical signs of stress reactions among individuals aged 18-24 years old who lived on the territory of enhanced radiation control were marked, in particular, raised level of cortisol (Sokolenko & Sokolenko, 2015), which increased further in conditions of additional psycho-emotional stress (Sokolenko, 2015). As a result, signs of immunosuppression were observed in this group, which were accompanied by an imbalance of thyroid status and lipid metabolism, changes in oxidative and antioxidant activity (Sokolenko & Sokolenko, 2015, 2017a2017b;Sokolenko 2016).…”

“…Oxidative damage correlates with the level of cholesterol of low density lipoprotein (Hs-LDL) and triglycerides (Fernández-Sánchez et al, 2011). Indeed, we have already shown that the level of total cholesterol and Hc-LDL was increased in the experimental group, and so, the level of Hc-LDL positively correlated with the number of stab neurotrophils (Sokolenko, 2016;Sokolenko & Sokolenko, 2017a). This may indicate stimulated by hypercholesterolemia activation in the development of neutrophils in the bone marrow and spleen, which, in turn, creates preconditions for the development of inflammatory reactions (Tall & Yvan-Charvet, 2015).…”

“…It is known that the thyroid gland takes part in the development of oxidative stress by stimulating several enzyme systems (De Vito et al, 2011), we also indicate the possibility of the impact of this phenomenon on immune cells proliferation and migration of (Barreiro et al, 2011). In our previous reports, the relationship between the thyroid status of individuals from radiation-contaminated territories, their lipid profiles and the immune system was characterized (Sokolenko & Sokolenko, 2017a, 2017b.…”