Журнал «Здоровье ребенка» 1 (52) 2014

Introduction. Complex ecological situation in Ukraine, anthropogenic pollution of the environment significantly affect the formation of population health; and sensitization of the organism by ecotoxicants is a major cause of ecological disadaptation syndrome that occurs after prolonged exposure to even low concentrations of toxic substances. The endocrine system, particularly thyroid gland is highly sensitive to the toxic exogenous effects. The negative impact of environmental pollution on the thyroid gland is complicated by the fact of endemic iodine deficiency in many regions of Ukraine. At present, most of thyroid doctors believe that organism adequate iodine providing is necessary for the thyroid gland protection from exposure to other gland gene.

Materials and methods of the research: The study involved only 72 children. Of these, 32 children are living from their birth in ecologically unfavorable iodine deficiency area (EU IDA) Ivano-Frankivsk region – Bohorodchany area; and 40 children are living from their birth in ecologically conventionally clean iodine deficiency area (ECC IDA) Ivano-Frankivsk region – town Gorodenka that composed the control group. All the children at the time of the survey were in the age range from 6 to 13 years. Previously it was a review of children and anthropometric measurements with subsequent calculation of body surface area (BSA). It was reviewed size of the thyroid gland (TG) by palpation and ultrasonography (USG) using a portable ultrasound scanner My Sono by linear transducer with a frequency of 5 MHz considering BSA. Study level of triiodothyronine (T3), thyroxin (T4), thyroid stimulating hormone of hypophysis (TSH) in serum were determined by standard test sets of the firm "Ham" (Russia) by enzyme-linked immunosorbent assay (ELISA method); and the reaction leukolysis by micromethod described by Ye.A.Maylyan and A.S.Prylutskym (1991year), reflecting the individual sensitivity of the child organism to certain environmental pollutants was investigated. Blood for the study was collected for 24 hours before sampling analysis. Laboratory studies were conducted in the laboratories of the Institute of Hereditary Pathology, Academy of Medical Sciences of Ukraine (Director – Professor Hnateyko O.Z). Statistical analysis of the research results was carried out by the conventional method using a personal computer software package "Statistica".

Results of the research: Despite the ongoing high level of attention to the problem of iodine deficiency diseases and improving methods of preventing environmental degradation exacerbates iodine deficiency, which creates the conditions for an increase in thyroid pathology. Analysis of the results of the study showed a significant prevalence of diffuse goiter endemic among children EU IDA Ivano-Frankivsk region compared with ECC IDA by ultrasound .To determine the degree of increase in thyroid ultrasound used three standards : standards for BSA and gender as recommended by the Ministry of Health of Ukraine , and more recent standards – for BSA and gender and by age and sex, recommended by WHO. Therefore, when comparing the frequency of goiter among groups of children with iodine deficiency EU and ECC, at was found significant difference 34.3 % vs. 17.5 % (according to normative data of Ministry of Health of Ukraine) and 90.6 % versus 52.5 % (according to the WHO), indicating that environmentally unfriendly environment along with iodine deficiency contribute to an increased incidence of diffuse endemic goiter in children living in ecologically unfavorable areas. It was found out that children who live in EU IDA and ECC IDA the level of TSH in serum of children within the optimal values (0,4–2,0 IU/L) had more than half of children 19 (59.2 %) and 29 (72.5 %) children , respectively. Signs of minimal thyroid dysfunction (TSH increase to 2,4–4,0 IU/L) in children with EU IDA detected in 11 (34.4 %) and 10 (25 %) of ECC IDA, which revealed no significant difference between themselves. In a state of sub clinical hypothyroidism (TSH levels above 4.0 IU/L) were 2 (6.4 %) and 1 (2.5%) children, respectively. The concentration of T3 in the serum of children with EU IDA with increasing degree of hyperplasia of the thyroid gland (HTG) decreased from 3,00 ± 0,21 nmol/l to 1,50 ± 0,09 nmol/l, and from 2,30 ± 0,17 to 1,16 ± 0,03 nmol/l in the group of children from ECC IDA, but remained within physiological fluctuations. Children of the studied groups TSH II-III degree the level of T3 was on average twice lower than in children without TSH. This is possible evidence of reduced functionality gland, despite its considerable hyperplasia .Content thyroxin in serum in children with EU IDA with increasing degree TSH decreased from 162,76 ± 15,24 to 92,35 ± 8,01 nmol/L, respectively . In the group of children from ECC IDA, on the contrary , the concentration of T4 in serum was raised with increasing degree TSH from 119,4 ± 22,1 to 159,1 ± 18,3 nmol/l, although this indicator in both study groups was within the physiological fluctuations. Thus, ecologically adverse environment residents functional activity of the thyroid on the synthesis of T3 and T4 are clearly reduced, although hyperplasia, indicating a reduction of compensatory mechanisms.

Conclusions.

1. A significant incidence of goiter from 34.3 to 90.6 % (according to the norms of Ministry of Health of Ukraine and WHO, respectively) in the group of children from EU IDA and from 17.5 to 52.5 % in the group of children from ECC IDA, confirms the presence of iodine deficiency and unresolved issues of preventing iodine dependent component diseases.

2. The reliability of the difference (p < 0,01) between the frequency of goiter rates in the groups of children from EU IDA and children from ECC IDA indicates the influence of geochemical and anthropogenic factors that potentiate iodine deficiency, leading to the formation of a high frequency of thyroid disease in children living in environmentally contaminated area.

3. Analysis of the regulatory function of the pituitary gland (TSH) on the functional activity of the thyroid gland showed a tendency to increase the level of TSH in children of two groups that increasingly observed in children with EU IDA. This is due to the increased need for thyroid hormones in children from the study area.

4. The inhabitants of iodine deficiency ecologically adverse environment functional activity of the thyroid on the synthesis of T3 and T4 are clearly declining, despite the degree of hyperplasia, indicating a reduction of compensatory mechanisms. This can be explained by "environmental stress ", which leads to easier occurrence of these children ' failure ' adaptive capacities.