Olga A. Baitrak, Pediatrist, Teacher of the Department of Childhood Diseases
Surgut
Vitaly V. Meshcheryakov, Dr. Sci. (Med.), Pediatrist, Professor, Head of the Department of Childhood Diseases
Surgut
Tatiana, M. Somova, Cand. Sci. (Med), Senior Lecturer of the Department of Childhood Diseases
Surgut
Objective: to evaluate the efficiency of the assessment of physical and sexual development, and blood pressure indicators of school-age children of the ethnic Khanties using standards developed on this cohort in comparison with the use of standards that are not adapted to them. Material and methods: the authors assessed of physical and sexual development, and blood pressure indicators in 423 ethnic Khanty children aged 7 to 17 years using standards developed on a cohort of children of the Khanty, the alien population of the north, and international standards. Results: statistically significant differences in the results of the assessment of anthropometric data, blood pressure, and sexual development were found using standards developed on different cohorts of children. The application of standards for the alien population of the north and international standards distorts the conclusion about the assessment of the health of children of ethnic Khanty and contributes to the underdiagnoses of obesity, excess body weight, and arterial hypertension, overdiagnoses of nanism, and a delay in sexual development. Conclusion: the presence of features of physical and sexual development, and blood pressure of ethnic Khanty children determines the need in the standards developed on this ethnically isolated cohort of children for individual and population assessment of their health.
Цель: исследовать результативность оценки показателей физического, полового развития и артериального давления детей школьного возраста этнических хантов при использовании разработанных на этой когорте нормативов в сравнении с применением не адаптированных к ним норм. Материалы и методы: оценка показателей физического, полового развития и артериального давления 423 детей этнических хантов в возрасте от 7 до 17 лет с использованием нормативов, разработанных на когорте детей хантов, пришлого населения севера, и международных стандартов. Результаты: установлены статистически значимые различия результатов оценки антропометрических данных, артериального давления и полового развития при использовании нормативов, разработанных на различных когортах детей. Применение нормативов для пришлого населения севера и международных стандартов искажает заключение об оценке здоровья детей этнических хантов, что способствует гиподиагностике ожирения, избытка массы тела и артериальной гипертензии, гипердиагностике нанизма и отставания в половом развитии. Заключение: наличие особенностей физического, полового развития и артериального давления детей этнических хантов определяет необходимость использования для индивидуальной и популяционной оценки их здоровья нормативы, разработанные на этой этнически обособленной когорте детского населения.
Individual and population assessments of children's health constitute an important section of pediatrics and are the subject of pediatricians' daily work. A comprehensive assessment of children's health includes, first of all, the analysis of indicators of physical and sexual development and blood pressure (BP), which are indicators of health in general, and their deviation from the norm requires further examination to make a nosological diagnosis [
Despite the availability of international standards for these indicators, including those recommended by the World Health Organization (WHO), most authors consider it necessary to develop regional standards, including those for a particular ethnic group.
The need for this is justified by the presence of climatic-geographical, social, and biological (including genetic) features that can directly or indirectly influence the rate of physical and sexual development and the level of BP [
Such populations include the small indigenous peoples of the North (IPNS), who have preserved their ethnic isolation and semi-nomadic way of life up to the present day to the maximum extent possible. Separate studies are devoted to the study of the anthropological features of IPNS [
In the Khanty-Mansi Autonomous Area – Yugra, the IPNS representatives are mostly Khanty. Khanty children of school age stay with their parents in the summertime in the fields, raising reindeer, fishing, gathering taiga berries and mushrooms, and during their school years, they live in a boarding school.
The use of standards not developed on IPNS cohorts distorts the assessment of their health status. The absence of basic standards of their health status (physical, sexual development and BP) adapted for Khanty children was the basis for the development of such standards [
The aim of the study is to investigate the effectiveness of the assessment of physical, sexual development and BP parameters of ethnic Khanty school-age children when using the standards developed on this cohort in comparison with the use of non-adapted norms to them.
A full cohort comparative study was conducted: the results of the assessment of physical, sexual development and BP of ethnic Khanty children were analyzed using various standards. The authors analyzed the results of the annual preventive examination in the boarding school for IPNS of the Russkinskiye settlement of the Surgut District of the Khanty-Mansi Autonomous Area –Yugra, conducted in accordance with the Order of the Ministry of Health of Russia of August 10, 2017 No. 514n (revised on November 19, 2020) "On the Order of Preventive Medical Examinations of Minors". Physical development and BP were assessed in 423 students aged 7–17 years (228 boys, 195 girls), sexual development was assessed in 284 of them aged 10–17 years (132 boys, 152 girls). Only those children whose parents were both members of that ethnic group were considered ethnic Khanty.
Two methods were used to assess physical development such as percentile and Z-score. All the examined children were distributed in the corridors of percentile values (≤ 3%; > 3 < 25%; 25–75%; > 75 < 97%; ≥ 97 %) and SDS (less than -2SDS; from -2 SDS to -1 SDS; from -1 SDS to +1SDS; from +1SDS to +2SDS; more than +2 SDS).
Anthropometry was performed according to the standard technique. All children were divided into three groups when assessing their sexual development according to the Tanner method: passport age compliance, the advance of passport age, and lagging behind. BP was measured by Korotkov’s auscultatory method, and children were divided into the following groups: normal BP (systolic and diastolic BP between the 25th and 90th percentile for a given height, age, and sex); high normal BP (systolic and/or diastolic BP between the 90th and 95th percentile for a given height, age, and sex); arterial hypertension – AH (systolic and/or diastolic BP over the 95th percentile for a given height, age, and sex).
The structure of the obtained distributions was presented as a percentage. The authors compared the same type of relative indices in % when assessing them by three methods – using basic and the authors' standards (separately for the native and Khanty population).
The WHO standards [
At the same time, to compare the results of the assessments, the authors used the standards developed and presented earlier for the children of the native population of the Khanty-Mansi Autonomous Area –Yugra and separately for ethnic Khanty [
This stage of the work was a test, the study was conducted on a separate group of ethnic Khanty whose data were not used for the development of standards (physical, sexual development and BP).
The statistical significance of intergroup differences in relative indices (%) was investigated by the Fisher angular transformation method. The threshold value of statistical significance was p = 0.05.
The data presented in Table 1 testify to the presence of statistically significant differences in the results of the assessment of the physical development of ethnic Khanty children when using different standards.
Table 1
The results of the assessment of physical development indicators of children aged 7–17 years of ethnic Khanty (n = 423) according to their preventive examination at school using various standards: WHO/the authors' data, alien population/the authors' data, ethnic Khanty
Note: comparative intergroup estimation by the Fisher angular transformation method; * – p < 0.05 between the data results obtained using the WHO standards and the authors' standards for ethnic Khanty; ** p < 0.05 between the data results obtained using the authors' standards for the alien population and the ethnic Khanty; *** p < 0.05 between the data results obtained using the WHO standards and the authors' standards for the alien population.
Indicators | Height | Weight | Body mass Index | ||||||
WHO standards | Standards of authors | WHO standards | Standards of authors | WHO standards | Standards of authors | ||||
Alien population | Khanty | Alien population | Khanty | Alien population | Khanty | ||||
Distribution of boys (%) in the evaluation of the centile tables (n = 228) | |||||||||
≤3 % | 17.8*** | 22.2** | 3.80* | 14.90 | 15.1** | 3.20 | 0.40 | 0.40** | 3.20* |
>3<25 % | 53.2*** | 64.2** | 21.7* | 34.9*** | 51.0 ** | 22.9 * | 22.2*** | 26.6 | 22.2* |
25-75 % | 26.4*** | 13.2** | 54.8* | 48.3*** | 31.3 ** | 49.7 | 62.7 | 62.7** | 49.7* |
>75<97 % | 2.60*** | 0.40** | 16.5* | 1.90*** | 2.6 0 | 21.0 * | 13.5*** | 10.3** | 21.7* |
≥97 % | 0.00 | 0.00 | 3.20 | 0.00 | 0.00 | 3.20 | 1.20 | 0.00 | 3.20* |
Distribution of girls (%) in the evaluation of the centile tables (n = 195) | |||||||||
≤3 % | 31.2*** | 37.7** | 3.10* | 15.5*** | 13.2 ** | 3.60 | 1.50 | 1.50** | 3.60* |
>3<25 % | 53.7 | 53.4** | 21.8* | 37.7 | 45.9 | 25.9 | 28.0*** | 26.8 | 23.0* |
25-75 % | 13.7*** | 8.40** | 50.9* | 44.9 | 37.3 | 47.6 | 61.2 | 58.0** | 49.7* |
>75<97 % | 1.50 | 0.50** | 20.6* | 1.90 | 3.60 | 19.6 | 9.40*** | 13.8** | 20.6* |
≥97 % | 0.00 | 0.00 | 3.60 | 0.00 | 0.00 | 3.10 | 0.50 | 0.50** | 3.10* |
Distribution of boys (%) on the Z-score scale (n = 228) | |||||||||
< -2SDS | 13.2*** | 21.3** | 2.70* | 4.70*** | 1.20 | 0.40 * | 0.40 | 0.00 | 0.90 |
-2 SDS … -1 SDS | 46.3 | 44.1** | 11.9* | 20.5*** | 37.7 ** | 9.50 * | 15.8 | 9.50 | 10.3* |
-1 SDS … +1SDS | 39.4*** | 34.6** | 72.7* | 65.5*** | 59.9 ** | 72.3 * | 81.5 | 84.3** | 70.2* |
+1SDS … +2SDS | 1.20 | 0.00 | 9.70* | 9.30*** | 1.20 | 11.4 ** | 1.40*** | 5.80** | 13.7* |
> +2 SDS | 0.00 | 0.00 | 3.20 | 0.00 | 0.00 | 6.40 | 0.90 | 0.40** | 4.90* |
Distribution of girls (%) on the Z-score scale (n = 195) | |||||||||
< -2SDS | 23.1*** | 32.6** | 2.60* | 4.60*** | 0.50 | 0.50 * | 1.50 | 1.00** | 0.50* |
-2 SDS … -1 SDS | 44.3 | 46.8** | 12.8* | 24.6 | 29.6 ** | 12.8 * | 8.40*** | 19.5** | 10.7 |
-1 SDS … +1SDS | 31.6*** | 19.5** | 70.3* | 65.3 | 68.4 | 68.4 | 80.4*** | 73.3 | 70.3* |
+1SDS … +2SDS | 1.00 | 1.50** | 12.8* | 5.50*** | 1.50** | 13.7 * | 9.20*** | 6.20** | 13.9* |
> +2 SDS | 0.00 | 0.00 | 1.50 | 0.00 | 0.00 | 4.6 | 0.50 | 0.00** | 4.60* |
The use of norms not developed on the Khanty cohort significantly increases the number of children with low and very low height and body weight, both when assessed by centile tables and by the Z-score. At the same time, the evaluation according to the norms developed on the cohort of ethnic Khanty children distributes the surveyed people in proportion to the specified percentiles. The incomplete coincidence with the distribution of healthy people is due to the fact that the verification stage included an assessment of the indicators of all children in a continuous method, including those with deviations from health in terms of physical development, and the standards were developed on the cohort of children of health groups I–II.
The bodily structure of ethnic Khanty children according to the derivative index of body mass index (BMI) characterizing the nutritional status also depended on the standards used for this purpose. The most important thing should be considered the statistically significant lower proportion of overweight and obese children when using standards not adapted for ethnic Khanty, both according to the centile evaluation of the BMI and the Z-score.
The established patterns applied equally to boys and girls.
Table 2
Results of the assessment of blood pressure indicators of children aged 7–17 years of ethnic Khanty (n = 423) according to their preventive examination at school using various standards: clinical recommendations of the Russian Federation/the authors' data, alien population/the authors' data, ethnic Khanty
Note: comparative intergroup evaluation by the Fisher angular transformation method; * – p < 0.05 between the data results obtained using the data presented in the clinical recommendations of the Russian Federation and the authors' standards for ethnic Khanty; * * p < 0.05 between the data results obtained using the authors' standards for the alien population and ethnic Khanty; *** p < 0.05 between the data results obtained using the data presented in the clinical recommendations of the Russian Federation and the authors' standards for the alien population.
Indicators | Russian clinical guidelines | Standards of authors | ||||
Alien population | Khanty | |||||
Absolute number | % | Absolute number | % | Absolute number | % | |
Arterial hypertension | 2 | 0.47 *** | 8 | 1.89 ** | 16 | 3.78 * |
High normal blood pressure | 13 | 3.07 *** | 24 | 5.67 ** | 40 | 9.46 * |
Normal pressure | 408 | 96.46 *** | 391 | 92.44 ** | 367 | 86.76 * |
The distribution of ethnic Khanty children according to the results of BP assessment into three groups (normal BP, high normal BP, and AH) was statistically significantly different when different standards were used (Table 2). The use of standards adapted to the cohort of ethnic Khanty children changes the specified structure in the direction of a greater share of children with BP abnormalities (AH and high normal BP).
Table 3
The results of the evaluation of sexual development indicators of children aged 10–17 years of ethnic Khanty (n = 284) according to their preventive examination at school using various standards: standards according to Tanner/authors' data, alien population/authors' data, ethnic Khanty
Note: comparative intergroup estimation by the Fisher angular transformation method; * – p < 0.05 between the data results obtained using the Tanner standards and the authors' standards for ethnic Khanty; ** p < 0.05 between the data results obtained using the authors' standards for the alien population and ethnic Khanty.
Indicators | J.M. Tanner | The authors’ standards | ||||
Alien population | Khanty | |||||
Absolute number | % | Absolute number | % | Absolute number | % | |
Girls (n = 152) | ||||||
Passport age compliance | 107 | 70.40 | 107 | 70.40 | 119 | 78.3 |
Lagging behind the passport age | 42 | 27.63 | 42 | 27.63** | 18 | 11.84* |
3 | 1.97 | 3 | 1.97** | 15 | 9,86* | |
Boys (n = 132) | ||||||
Passport age compliance | 79 | 59.68 | 79 | 59.68** | 101 | 76,52* |
Lagging behind the passport age | 51 | 38,63 | 51 | 38,63** | 15 | 11,36* |
Advance of passport age | 2 | 1.51 | 2 | 1.51** | 16 | 12.12* |
Analysis of the results of the Tanner method of sexual development assessment (Table 3) also showed statistically significant differences when using different standards. The use of standards developed not on the ethnic Khanty cohort (Tanner standards and the authors' standards for children of the non-Russian population) significantly increases the proportion of Khanty children with delayed sexual development and decreases the proportion of children with advanced development. The established pattern is characteristic of both sexes of children.
The data from this study show significant differences in the results of anthropometric data, BP, and sex development when using norms developed on different cohorts of children.
Previously, the authors described the phenotypic features of physical development indicators of ethnic Khanty children, characterized by lower height, body weight, and BMI [
Overweight was diagnosed in 27, 18, and 17 girls, respectively. The established patterns were statistically significant.
The data presented by the authors earlier indicate statistically significant differences in the BP indices of ethnic Khanty children compared to the immigrant population of the North, in the direction of their lower systolic and diastolic BP [
The higher prevalence of delay in sexual development when using standards not adapted for Khanty is associated with the previously presented features of the rates and some characteristics of sexual development of children in this cohort: a later debut of puberty and certain phenotypic features of secondary sexual characteristics (later completion of axillary hair formation in persons of both sexes, the absence of stage P5 of pubic hair formation and facial hair formation in young men) [
The presence of peculiarities of physical and sexual development indicators and BP of Khanty children determines the necessity of using the standards developed on this ethnically isolated cohort of the child population for individual and population assessment of their health in the course of preventive examinations. Using different standards distorts the health assessment and contributes to the overdiagnosis of obesity, overweight, and AH, overdiagnosis of nanism, and delayed sexual development.
The implementation of these standards developed on ethnic Khanty children makes it possible to objectify the assessment of their health status, establish the true incidence and prevalence of various deviations in physical and sexual development and AH, and plan health care resources more effectively to provide medical care for this group of children.
The authors declare that there are no conflicts of interest present.