Thyroid hormones play a crucial role in regulating normal development, growth, and metabolic function. However, the controversy surrounding seasonal changes in free triiodothyronine (FT3) levels remains unresolved. Therefore, the aim of this study was to conduct a systematic review and meta-analysis of variations in FT3 levels in relation to seasonal air temperatures in the context of current knowledge about its role in nonshivering thermogenesis. Ten eligible articles with a total of 336,755 participants were included in the meta-analysis. The studies were categorized into two groups based on the air temperature: “Cold winter”, where the winter temperature fell below 0 °C, and “Warm winter”, where the winter temperature was above 0 °C. The analysis revealed that in cold regions, FT3 levels decreased in winter compared to summer (I² = 57%, p < 0.001), whereas in warm regions, FT3 levels increased during winter (I² = 28%, p < 0.001). These findings suggest that seasonal variations in FT3 levels are likely to be influenced by the winter temperature. Considering the important role of the FT3 in the nonshivering thermogenesis process, we assume that this observed pattern is probably related to the differences in use of thyroid hormones in the brown adipose tissue during adaptive thermogenesis, which may depend on intensity of cold exposure.

Introduction: Interferon I (IFN I) signaling hyperactivation is considered one of the most important pathogenetic mechanisms in systemic lupus erythematosus (SLE). Early manifestation and more severe SLE courses in children suggest a stronger genetic influence in childhood-onset SLE (cSLE). Aim: To evaluate IFN-I score and SLE-associated genetic variants in cSLE. Material and Methods: 80 patients with cSLE were included in the study. IFN I-score was assessed by real-time PCR quantitation of 5 IFN I-regulated transcripts (IFI44L, IFI44, IFIT3, LY6E, MXA1) in 60 patients. Clinical exome sequencing (CES) was performed in 51 patients. Whole-exome sequencing was performed in 32 patients with negative results of CES. Results: 46/60 patients (77%) had elevated IFN-I scores. Leucopenia and skin involvement were associated with over-expression of IFI44 and IFI44L, while hypocomplementemia—with hyperactivation of IFIT3, LY6E, and MX1. No correlation of IFN-I score with disease activity was found. At least one rare genetic variant, potentially associated with SLE, was found in 29 (56.9%) patients. The frequency of any SLE-genetic variants in patients with increased IFN scores was 84%, in patients with normal IFN scores—33%, and in the group whose IFN score was not assessed was 65% (p = 0.040). The majority of genetic variants (74%) are functionally related to nucleic acid sensing and IFN-signaling. The highest frequency of genetic variants was observed in Sakha patients (9/14; 64.3%); three and two unrelated patients had identical variants in PTPN22 and TREX1 genes, respectively. Conclusions: More than half of patients with childhood-onset SLE have rare variants in SLE-associated genes. The IFN-I score could be considered a tool for the selection of patients for further genetic assessment in whom monogenic lupus is suspected.

BACKGROUND: The implementation of the major federal projects in the Arctic region of the Russian Federation claims particular attention to the indicators of the quality of life and the state of population health in these regions. Health and demographic indicators can be one of the available tools for public health monitoring. AIM: To analyze the main trends of the health and demographic processes in the arctic regions of the Republic of Sakha (Yakutia) over 20 year (20002020). MATERIAL AND METHODS: The data of the Territorial Body of the Federal State Statistics Service in the Republic of Sakha (Yakutia), YARMIATS for 20002020 were analyzed. An approximate 95% confidence interval was calculated over 20 years (20002019), the average population growth rate was estimated by a chain method for time series (data for 2020 year are presented separately due to the deformation of the pattern of demographic indicators due to the epidemic SARS-CoV-2). A linear regression analysis of IBM SPSS Statistics 26 was performed to assess the birth and mortality rate trends. RESULTS: From 20002020, the population of the Arctic region of the Republic of Sakha (Yakutia) decreased by 22% due to migration and high mortality rates. Deaths by external causes occupy approximately 20% of the structure of the all-cause mortality rate. Dynamically, the decrease in the number of infant mortalities was noticed due to the effective routing of pregnant women and improvement of the maternity service in the region. CONCLUSION: The analysis of the medical and demographic indicators showed positive and negative trends in the Arctic regions public health of the Republic of Sakha (Yakutia). The system of the healthcare organization in the regions is to be improved. Also, these regions, which possess all the features of the healthcare systems with low-density population territories, can become a model for the regional and federal projects approbated in the field of Arctic medicine.

Implementing major projects for development of the Arctic regions of the Russian Federation and ensuring sustainable economic growth of these regions, the government pays a special attention to the social development and improvement of medical care in remote and hard-to-reach areas of the Russian Arctic. In recent years, research of the peoples health and influencing factors have intensified. The Ministry of Health of the Republic of Sakha (Yakutia) carried out large federal and republican programs to develop the material and technical equipment and ensure appropriate staffing of medical institutions in the Arctic and northern regions. The Republic of Sakha (Yakutia) is one of the most isolated and hard-to-reach regions of Russia, therefore, development of medical care in the Arctic zone is particularly important. The article presents the characteristics of the Arctic zone of the Republic of Sakha (Yakutia), population density 1 km2, distance of settlements from the center. The percent of remote and hard-to-reach settlements in the arctic regions ranges from 38 to 80%. The network of medical institutions with analysis of equipment and staffing is presented in detail. The article reflects the specifics of medical care in the Arctic zone in the context of the territory scale. The identified peculiarities make it necessary to develop differentiated regional mechanisms of implementing the state policy of healthcare development in the regions of the Far North of the Russian Federation. It would be reasonable to consider the possibility of developing a medical care sub-program taking into account the Arctic specifics.

The results of dietary habits and preference of certain products in school children of Kysyl-Syr, Namsky region of the Republic of Sakha (Yakutia) are represented in the article. We have assessed nutrition and health status of 64 adolescents, aged from 12 to 16. The result of data analysis shows that children in Namsky region consume more meat rather than fish, unlike the children in the Arctic regions of the Republic of Sakha (Yakutia). Fish is consumed rarely, only several times a month - 48.4%, or even less than once a month - 37.5%. Beef is more consumed out of the other meat products. In the Arctic regions poultry and game products are eaten more. It is revealed that dairy products are daily consumed by a less than a half of the survey group - 39%, the rest 37.5% consume several times a week. A lack of vegetables and fruit in the diet results in significant drawback. Only 15.6% ate vegetables daily, and 12.5% ate fruit. Children prefer bakery and confectionary products. Food preferences of most of them are sweets, fizzy drinks and excessive amount of salt. We have examined and revealed the structure of morbidity in children of the Namsky region. Dental pathology was most commonly revealed (53.1%). In Namsky region people use water from the river Lena, where the fluoride level is low. The diseases of the respiratory system were present in 37.5%, mostly ENT disorders, which were possibly associated with unfavourable environmental conditions, chronic infections, incorrect dietary habits and stress. Muscular skeletal system diseases were present in 26.6%. Commonly it was associated with the deficiency of vitamin D, lack of exposure to sunlight, as there are few sunny days, and insufficient amount of vitamin D in the diet (fish, eggs, milk). The obtained results revealed food habits in school children of the Central regions of the Republic of Sakha (Yakutia). The results of the survey require improved organization of the children dietary habits.

Objective. Analysis of the frequency of endemic goiter and indicators of the pituitary-thyroid profile in children aged 10-18 years living in the Arctic regions of Yakutia. Materials and methods. The study was conducted among children and adolescents of the Arctic regions of Yakutia (Bulunsky, Anabarsky, Allaikhovsky, Nizhnekolymsky, Verkhnekolymsky district) during field medical expeditions in 20182020. A total of 392 children aged 1018 years were examined. Results. In 30 % of the examined children, an increase in the thyroid gland was observed, which was accompanied by elevated levels of free thyroxine. In 3 % of children, an increase in the level of thyroid-stimulating hormone was detected against the background of reduced or normal levels of free thyroxine. Conclusions. As for the prevalence of cases of endemic goiter, the Arctic regions of Yakutia are the areas of severe goiter endemia. The results obtained justify the need for additional scientific studies to assess the degree of iodine availability (by the concentration of iodine in the urine) in different population groups and real implementation of the strategy of mass preventive measures.