[Prevalence of trehalase enzymopathy genetic determinants in Siberian and Russian Far East populations].

To date, it has been established that the patient's genotype plays a significant role in the formation of trehalase enzymopathy: the level of enzyme activity decreases when the G→A allele replacement occurs in the rs2276064 locus of the TREH gene. To assess the prevalence of trehalase deficiency, extensive population-based studies are needed. Clinical observations show that the reduced activity of bowel trehalase is more common in the Arctic than in European populations. The aim of this research was to analyze the frequency of the alleles and variants of trehalase gene (rs2276064 TREH) in the indigenous small-numbered populations of Siberia and the Russian Far East. Material and methods. Using the Infinium iSelect HD Custom BeadChip biochip on the iScan platform and real-time polymerase chain reaction on a Bio-Rad CFX96 Touch amplifier, genotyping of 1068 DNA samples was carried out, of which 711 represent 10 ethnic groups of the indigenous people of the North of Siberia and the Far East of the Russian Federation. Two reference groups of Russians (n=311) and Yakuts (n=46) represented the "Caucasoid" and "Mongoloid" poles of the Russian population. Results. The reduced trehalase activity that the heterozygous GA*TREH genotype determines can manifest itself in 19.8-53.7% of indigenous northerners. An additional 1.0 to 19.7% of the population are carriers of the AA*TREH genotype, which is associated with apparent trehalose malabsorption. The carriers may experience nausea, abdominal pain, and other dyspeptic symptoms after eating trehalose containing foods. The total risk of trehalase enzymopathy among the indigenous northerners in the Asian part of the Russian Federation is very high and can reach 60-70%. There is a gradient in the A*TREH allele frequencies in the small-numbered indigenous northern groups of Russia from the west (Khanty, Mansi, Nenets) to the east (peoples of the Far East). Conclusion. The results are consistent with previously reported data on the higher carriage of the A*TREH mutant allele in Mongoloid populations compared to Caucasoid groups. It was hypothesized that, while the initial A*TREH allele prevalence in Mongoloid groups was moderately high, an adaptation to a low-sugar protein-lipid "high-latitude" diet led to a weaker control over the maintenance of the carriage of the ancestral G allele. Trehalose malabsorption requires special attention of specialists in the field of nutrition, gastroenterology, public health, and medical genetics working in high-latitude regions.

[Genetically determined trehalase deficiency in various population groups of Russia and neighboring countries].

Due to the low specificity and sensitivity of non-invasive clinical tests trehalose malabsorption remained out of sight of gastroenterologists. Therefore, the specialists regard this disorder as rare. Trehalose became widely used in the food industry as a harmless sucrose substitute, sweetener and stabilizer. After the discovery of the trehalase gene (rs2276064 TREH), it was found that the A*TREH allele is the determinant of the disaccharide absorption disorders, and the allele's carriership may be high in some groups. There is not enough information on the A*TREH frequency in the population of Russia. The aim of the study was to analyze the allele and genotype frequencies of the trehalase gene (rs2276064 TREH) in the main population groups of the Russian Federation and neighboring countries. Methods. DNA samples from 1146 unrelated subjects belonging to 21 population groups of Russia, Azerbaijan, Tajikistan and Mongolia were genotyped by the two following methods: 1) using the Infinium iSelect HD Custom Genotyping BeadChip (Illumina, USA) on the iScan platform; 2) by the real time polymer-chain reaction (PCR) method on the Bio-Rad CFX96 Touch amplifier. Results. It has been found that on the territory of the Russian Federation the frequency of the A*TREH allele increases from the west to the east. The frequencies are lowest in the groups of Russians and Finns of the Northwest (0.01-0.03), up to 0.07 in the populations of Central Russia and the Volga region, and even higher toward the Southern Urals (Bashkirs 0.15), in the Transurals and Southern Siberia (0.19 in the Altai people, 0.30 in the Tuvinians and Mongols). Up to 1% of the population of the European part of the Russian Federation have the AA*TREH genotype (i.e. trehalose intolerance in phenotype), and up to 15% (GA*TREH genotype) have a reduced ability to absorb the disaccharide. In the Asian part of the country (Siberia, Altai, Baikal) the genotypes carriers constitute up to 12 and 46% respectively. Conclusion. Trehalose malabsorbtion is an underappreciated problem of particular practical importance for regions with high concentrations of indigenous population (Yakutia-Sakha, Buryatia, Tyva, etc.). It would be feasible to consider food labelling of trehalose.

[Nutritional status of children in rural areas of the Komi Republic and Khanty-Mansi Autonomous Okrug - Yugra by anthropometric data].

A characteristic feature of the "global obesity epidemic" in recent decades is the rapid spread of overweight among the rural population. However, there is a lack of objective data on how this process is unfolding in the northern and Arctic regions of the Russian Federation. The aim of the work was to analyze the prevalence of malnutrition and rates of overweight and obesity in children living in Khanty-Mansi Autonomous Okrug - Yugra (KhMAO) and the Komi Republic (KR). Material and methods. We conducted a study of the nutritional status of rural children in the northern regions of the Russian Federation in 2018-2019. The subjects of the study were children aged 3-17 years of KhMAO, ethnic Khanty, Mansi and of various non-indigenous descent in small remote settlements (n=302) and 956 children in the administrative center of the northern district, a town-type residency. We also examined 7-17-year-old children (n=628) in large settlements of the KR, over 90% of them were ethnic Komi. For each individual, body mass index values (BMI) were calculated. The nutritional status was assessed by comparing the individual BMI with the age and sex specific standards set by the Ministry of Health of the Russian Federation (2017). Results and discussion. 74.4% of children aged 3-6 in KhMAO, and 70% of the 7-17-year-old children of KR and KhMAO meet the standards for their age-sex groups; 6.1% of children aged 3-17 are underweight and 19.5% are overweight. Among the 7-17-year-olds, the ratio of the underweight and overweight (including obese) differs significantly in the settlement dwellers of the KR from that in the living in small settlements of KhMAO (p=0.004), as well as in the group of town residents of KhMAO (p=0.017). The children of the KR have slightly higher percentage of the overweight and obese (26.6 vs 25.7 and 24.8% in the town and settlements of KhMAO, respectively), but significantly lower percentage of those who are underweight (1.9 vs 5.0 and 6.8%). The proportion of obese schoolchildren in small remote settlements of KhMAO is higher than that in the large settlements of KhMAO and in large settlements of the KR (13.1, 7.7 and 9.2%, respectively). Conclusion. There were no differences found between ethnic groups, however the role of social and anthropological factors in the formation of the nutritional status differences between the indigenous and non-indigenous children in Western Siberia calls for further investigation.

[Anthropometric indicators of physical development and nutritional status employed in hygiene practice in Russia].

In the current review, we consider the main working methods of Russian hygienists to assess anthropometric indices using a) regional data on (populational) variability of the concerning measurements and b) unified reference data applicable in most regions. An analysis showed that in most cases, the regional standards are based on average values and variabilities derived from a local sample, which can not serve as a working normative. As a result, these so called "standards" do not provide information on how healthy children should develop, and the assessments inferred are difficult to integrate to draw a picture for the whole country. In 2017, the Ministry of Health of the Russian Federation recommended the use of the WHO Child Growth Standards and the WHO Growth Reference for the purpose of medical screenings in children and adolescents. These data sets reflect the conditions, that healthy children should attain growing in supportive environment, with adequate nutrition and care. The single set of criteria will allow unifying the data collected in different regions, which is a necessity in communal hygiene and medical statistics. However, additional research is needed to check the validity of the WHO standards and reference to assess physical development and nutritional status in highly anthropologically specific populations, in particular in those indigenous and long-ago adapted to the sharply continental or Arctic climate.