Comparative characteristics of the growth of male children and adolescents living in the Middle Ob Region

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INTRODUCTION

The physical development of children and adolescents has traditionally attracted sustained interest from researchers worldwide, as anthropometric characteristics serve as sensitive indicators of both the biological and socio-ecological well-being of the population [1–3]. In the scientific literature, child development is actively studied along ethno-geographic lines, distinguishing not only large ethnic groups but also individual areas, cities and settlements within a single country or even a region [4–7]. Some studies emphasize the need to account for climatic and geographic factors that determine variations in body size already in newborns and infants [8].

Often, the respondents are divided into rural and urban population groups, which allows to account for the influence of urbanized environment and anthropogenic burden on the anthropometric status [7, 9, 10]. Contemporary research particularly focuses on the dynamic approach, which involves assessing changes in anthropometric parameters over time based on long-term observational series. Such an approach is implemented, in particular, in the study of L.S. Tupitsyna (2015), which traces the dynamics of body weight, body length and circumferences in newborns in a northern region over the period from 1990 to 2011 and demonstrates the sensitivity of these traits to socio-economic and environmental changes [11].

I.V. Gayvoronskiy et al. (2022) [12] view the anthropometric approach as a key instrument in the definition of parameters of physical development and constitutional types, especially in the combination with consecutive repeated examinations of the same age groups, which allows for an objective assessment of environmental factors and medical and hygienic monitoring of health. The works of O.G. Litovchenko et al. (2015, 2021) and A.A. Govorukhina et al. (2020) [13–15] provided important data on specific age groups; at the same time, these studies, similar to many regional studies, are restricted by relatively narrow temporal and territorial boundaries and preclude analysis of continued ontogenetic development of children of the Middle Ob Region until the age of maturity. With this background, studies aimed at filling this gap and constructing a comprehensive picture of the physical development of children and adolescents in northern territories, based both on geographic variations in newborn body size and on long-term observational series of anthropometric parameters, become particularly relevant [8, 11].

AIM

To assess and compare anthropometric growth data of boys from the indigenous small-numbered peoples of the North and the newcomer population of the Middle Ob Region.

MATERIAL AND METHODS

The clinical site to collect the material for the study was three medical institutions of the city of Surgut: municipal polyclinic No. 2, district polyclinic and clinical hospital. The studied cohort included boys of two population groups permanently living in the Middle Ob Region: representatives of small indigenous peoples of the North (SIPN), viz. Khanty, and children from newcomer families (European descent living in the region for 2 or 3 generations).

Inclusion criteria: availability of voluntary informed consent duly formalized by a child's lawful representative, delivery at term, male sex, I–II health status groups, different feeding types (breast, mixed, formula) and favorable social and household living conditions. The total number of people in the analyzed sample was 20,051 males aged 0 to 17 years, of which 6,220 people were Khanty and 13,831 people were newcomers. Anthropometric measurement of body length/height was performed according to the standard method described by V.V. Bunak, in strict compliance with the established hygiene and methodological requirements.

Statistical data processing was performed using Statistica 13.0 software, with descriptive statistics and testing for normal distribution, as well as graphical presentation of results in Microsoft Excel. Normality of each numerical dataset was assessed by comparing its central tendency measures (arithmetic mean, M; mode, Mo; median, Me), as well as by calculating kurtosis (Ex) and skewness (As). Intergroup comparisons of trends in mean values, given the normal distribution of the studied parameters, were performed using Student's t-test. For normally distributed data, numerical values are presented as M ± SD; differences were considered statistically significant at p < 0.05.

RESULTS AND DISCUSSION

After the analysis was performed and the obtained data were compared, the following was established. At birth, the body lengths in the groups are practically the same (52.01 cm in the SIPN group and 51.8 cm in the newcomer group; p = 0.86) indicating the lack of significant inter-population differences in the initial body length. The trend sustains for the entire year. The variability of this parameter in the infancy remains moderate (SD 2.0–3.1 cm) with minor increases by the age of 12 months, which shows relatively uniform rates of linear growth in the populations at this stage of development (Table 1).

 

Table 1. Growth dynamics of boys in the neonatal and infancy periods

Таблица 1. Динамика роста мальчиков периода новорожденности и грудного возраста

Age	SIPN		Newcomers		p-value
	N	M ± SD	N	M ± SD
0 months	216.00	52.00 ± 3.18	210.00	51.81 ± 2.24	0.86
1 month	241.00	54.94 ± 2.39	197.00	55.53 ± 1.81	0.67
2 months	239.00	58.43 ± 2.64	213.00	59.40 ± 1.79	0.72
3 months	242.00	61.50 ± 2.41	220.00	62.52 ± 1.82	0.69
4 months	238.00	63.62 ± 2.30	211.00	65.14 ± 2.01	0.11
5 months	240.00	65.30 ± 2.28	251.00	67.31 ± 2.03	0.29
6 months	239.00	67.20 ± 2.20	218.00	68.40 ± 2.32	0.34
7 months	239.00	68.41 ± 2.33	245.00	70.00 ± 2.02	0.18
8 months	249.00	70.14 ± 2.32	267.00	71.62 ± 2.00	0.41
9 months	230.00	71.60 ± 2.30	201.00	72.50 ± 2.33	0.36
10 months	225.00	73.40 ± 2.31	198.00	74.23 ± 2.00	0.32
11 months	223.00	74.50 ± 2.44	204.00	75.50 ± 2.33	0.24
12 months	216.00	76.00 ± 2.75	201.00	76.92 ± 2.70	0.17

 

In the following months of the infancy, the values of body length on both populations are growing significantly, reaching, by the age of 12 months, 76.0 cm in the Khanty and 76.9 cm in the newcomer group; throughout the entire interval before 12 months the metrics of the newcomer population do not statistically exceed those of the SIPN (p > 0.05). The relative rates of growth in both groups are the highest in the first months of life (5.1–7.2% per interval) and gradually decrease by the end of the first year of life (Fig. 1). At the age of 1-2 months, the newcomer population demonstrated the highest growth rates (7.1–7.2%), while in the SIPN group they are somewhat lower (5.8–6.4%), manifested by a sharper initial increase in the group. Between the age of 3–4 months and the end of infancy, two periods are marked: the growth rates decrease to 3.1–3.3% by the age of 5–6 months and to 1.4–2.0% by the age of 11–12 months. It the SIPN group, the decrease rate is more significant, and in the newcomer group, there are ‘waves' due to alternating intervals with close (2.1–2.2%) and remote (1.4–2.0%) values.

 

Figure 1. Dynamics of growth in boys during the neonatal and infancy periods.

Рисунок 1. Динамика прироста роста мальчиков периода новорожденности и грудного возраста.

 

In the early childhood (Table 2), the growth of boys continues at high, albeit gradually decreasing rates with deeper inter-population differences. At the age of 15 and 18 months, the values of body length of Khanty and newcomer boys are quite similar (78.1 and 81.3 cm vs. 80.0 and 82.1 cm, respectively), and these differences are either at the borderline of statistical significance (p = 0.059) or are merely biased (p < 0.49). Starting from the age of 21 months, the newcomer population clearly starts to prevail: at the age of 21 month, the gap is 2.4 cm (85.3 cm vs. 82.9 cm; p < 0.01), and by 33 months, already 5.0 cm (95.0 and 90.0 cm, respectively; p < 0.001).

 

Table 2. Growth dynamics of boys in early childhood

Таблица 2. Динамика роста мальчиков периода раннего детства

Age	SIPN		Newcomers		p-value
	N	M ± SD	N	M ± SD
15 months	173.00	78.10 ± 2.99	105.00	80.00 ± 2.48	0.06
18 months	169.00	81.31 ± 3.34	104.00	82.13 ± 2.88	< 0.49
21 months	147.00	82.90 ± 3.27	90.00	85.31 ± 3.01	< 0.01
2 years	149.00	85.03 ± 3.22	104.00	88.92 ± 3.60	< 0.001
27 months	114.00	87.24 ± 3.42	109.00	89.10 ± 2.84	< 0.001
30 months	114.00	88.90 ± 3.54	116.00	91.50 ± 3.50	< 0.001
33 months	107.00	90.00 ± 3.83	122.00	95.00 ± 4.22	< 0.001

 

The relative growth rates in the Khanty group in this period decrease from 2.6–3.8% at the age of 15–18 months to 1.1% at 30–33 months, whereas in the newcomer group they stay at higher levels reaching 3.8% in the period of 30–33 months (Fig. 2). Such a combination of moderately higher growth rates and initial ‘reserve' in body length leads to an accelerated widening of the intergroup gap by the end of early childhood. Variability of the trait increases in both populations (SD 3.4–4.2 cm), reflecting a broadening of the range of individual growth trajectories during this age period.

 

Figure 2. Dynamics of growth in boys during early childhood.

Рисунок 2. Динамика прироста роста мальчиков периода раннего детства.

 

Unlike those in the infancy period (Fig. 2), the curves on the histogram are closer to one another, the ups and downs are clearly seen that reflect the staging of decrease in the growth rate. In the Khanty group, after the still relatively high results at the age of 15–18 months (2.6–3.8%), the histogram curve tends to gradually go down: the growth rates go down to 2.4–2.5% at the age of 21–27 months reaching a minimum of 1.1% at the age of 30–33 months, forming a smooth downward curve without stark fluctuations. In the boys from the newcomer group, conversely, a more marked undulating nature of the graph is seen: after the initial 2.5–3.9% at the age of 15–18 months, the curve goes down to 2.3–2.4% at 21–27 months, followed by another raise to 2.8–3.8% at 30–33 months, showing a repeated increase of growth rates by the end of early childhood.

In the first period of childhood (Table 3), boys of both groups continue demonstrating an intensive linear growth, but the difference between the populations becomes more manifested. As early as at the age of 3 years, the average height of the Khanty is 92.8 cm, whereas in the newcomer group it is 98.4 cm (difference of 5.6 cm; p < 0.001); by the age of 7 years, the metrics reach 117.0 and 124.7 cm, respectively (difference of 7.7 cm; p < 0.001). In the entire duration of the period of 3–7 years, the lines of histograms of median values do not overlap: the newcomer group steadily demonstrates higher growth rates.

 

Table 3. Growth dynamics of boys during early childhood

Таблица 3. Динамика роста мальчиков периода первого детства

Age	SIPN		Newcomers		p-value
	N	M ± SD	N	M ± SD
3 years	113.00	92.82 ± 3.21	185.00	98.42 ± 5.44	< 0.001
3.5 years	107.00	94.94 ± 3.80	207.00	102.50 ± 5.00	< 0.001
4 years	105.00	99.00 ± 3.52	191.00	106.00 ± 5.67	< 0.001
4.5 years	110.00	102.13 ± 4.19	164.00	111.21 ± 5.43	< 0.001
5 years	100.00	105.30 ± 4.65	203.00	113.09 ± 5.02	< 0.001
5.5 years	101.00	108.00 ± 4.14	203.00	115.50 ± 3.82	< 0.001
6 years	109.00	112.32 ± 4.21	259.00	119.00 ± 4.28	< 0.001
6.5 years	104.00	115.09 ± 4.00	286.00	121.30 ± 4.00	< 0.001
7 years	163.00	117.00 ± 4.12	991.00	124.67 ± 4.41	< 0.001

 

Growth rates in the Khanty population during this period are characterized by marked fluctuations, with peaks of 4.2% at 3–4 years and 3.7% at 5.5–6 years, which may indicate separate periods of relative growth acceleration. Standard deviations in the newcomer population are slightly larger (up to 5.6 cm) compared to the Khanty (up to 4.6 cm), suggesting a wider spectrum of individual body sizes and, probably, greater heterogeneity in growth conditions within this group.

The dynamics of relative body length gains during the period of first childhood, when overall growth rates slow down but remain relatively stable, are illustrated in Fig. 3. The curves show the inherent unevenness with alternating moderate rises and declines. In the Khanty population, a marked rise is seen at the age of 3–4 years (4.2%), followed by a gradual decrease to 2.9% at the age of 4.5–5 years with a subsequent new rise to 3.7% at 5.5–6 years; after 6–7 years, the gains go down to 1.7% by the end of the period. In the newcomer population, in the beginning of the period, there are even higher growth rates in the waves: 3.7–4.1% at the age of 3–3.5 years and 3.4–4.7% at 4–4.5 years, after which the growth rate decreases to 1.8–2.2% at 5–5.5 years, decreasing again to 3.0–3.3% at 6–7 years. Overall, the curve of the newcomer population has sharper spikes and more manifested fluctuations, showing a greater increase of acceleration and deceleration phases of growth in comparison with SIPN.

 

Figure 3. Dynamics of growth in boys during early childhood.

Рисунок 3. Динамика прироста роста мальчиков периода первого детства.

 

In the second childhood period (Table 4), the contrasts between populations reach maximum manifestation. At the age of 8 years, the average height of Khanty boys is 121.8 cm, whereas that of newcomer boys is 130.0 cm (difference: 8.2 cm; p < 0.001); by the age of 12 years, the metrics grow to 142.1 and 156.6 cm, respectively (difference: 14.5 cm; p < 0.001). AT this stage, the growth curves of the two populations diverge the most (Fig. 4).

 

Table 4. Growth dynamics of boys during the second childhood period

Таблица 4. Динамика роста мальчиков периода второго детства

Age	SIPN		Newcomers		p-value
	N	M ± SD	N	M ± SD
8 years	199.00	121.82 ± 5.34	927.00	130.00 ± 4.79	< 0.001
9 years	132.00	127.00 ± 5.11	862.00	135.81 ± 4.92	< 0.001
10 years	121.00	131.70 ± 6.00	889.00	140.93 ± 5.14	< 0.001
11 years	100.00	135.82 ± 5.33	817.00	145.71 ± 5.50	< 0.001
12 years	105.00	142.12 ± 5.11	781.00	156.62 ± 5.38	< 0.001

 

Figure 4. Dynamics of growth in boys during second childhood, adolescence and youth.

Рисунок 4. Динамика прироста роста мальчиков периода второго детства, подросткового и юношеского возраста.

 

The relative growth gains in the Khanty group in the age period of 8–12 years vary from 3.0 to 4.4% per interval peaking at the age of 11–12 years (4.4%), whereas in the newcomer group they vary in the range of 3.5–6.2%, peaking values being observed at the age of 11–12 years (6.2%). Thus, in the newcomer population, the maximum growth rate occurs at approximately 12 years of age, whereas in the Khanty it is shifted to a later time point, between 12 and 13 years, as evidenced by a more gradual increase in growth increments and a moderate rise at the end of second childhood.

Variability in height in both populations increases by this age (SD 5.1–5.5 cm), reflecting considerable heterochrony in the onset of the pubertal growth spurt among individuals.

In the adolescent and youth age (Table 5), the boys continue growing, but the growth rates decelerate significantly, which matches a transition from the phase of puberty acceleration to completion of somatic growth. At the age of 13, the height of the Khanty boys is 145.6 cm, and that of newcomers is 159.7 cm (difference: 14.1 cm; p < 0.001); at the age of 14 years, 153.8 and 165.9 cm (difference: 12.1 cm; p < 0.001). By the age of 17, the average height of the Khanty boys reaches 164.0±4.9 cm, whereas in the newcomer group it is 174.3 cm (difference: 10.3 cm; p < 0.001), indicating preserved significant differences between populations by the end of the linear growth stage. The relative growth rates of the Khanty group in the period of 13–17 years decrease from 4.8% (13–14 years) to 1.2% (16–17 years), in the newcomer population, from 3.2–3.8% to 0.6% within the same period. The maximum gains in the Khanty groups are seen at 13–14 and 15–16 years (4.8 and 2.9%, respectively), which corresponds to a later completion of the pubertal growth spurt compared to the newcomer population, where the most pronounced growth increment is observed as early as at 12–13 years of age. Standard deviations in adolescence remain somewhat higher in the newcomer group (up to 7.4 cm) than in the Khanty group (up to 5.3 cm), indicating more pronounced interindividual variability in final body size and the rate of its attainment among the newcomer population.

 

Table 5. Growth dynamics of adolescent and young adult boys

Таблица 5. Динамика роста мальчиков подросткового периода и юношеского возраста

Age	SIPN		Newcomers		p-value
	N	M ± SD	N	M ± SD
13 years	103.00	145.62 ± 5.30	808.00	159.75 ± 7.44	< 0.001
14 years	98.00	153.81 ± 4.94	753.00	165.92 ± 6.81	< 0.001
15 years	129.00	157.50 ± 4.72	644.00	170.00 ± 5.91	< 0.001
16 years	111.00	162.13 ± 5.09	662.00	172.80 ± 5.73	< 0.001
17 years	100.00	164.00 ± 4.92	413.00	174.33 ± 5.78	< 0.001

 

The data on the gains in the second childhood, puberty and youth age and on the classic picture of the puberty growth spurt with distinct time indicators in the two populations are shown in Fig. 4. In the newcomer group, the growth rates after the relatively moderate values of the second childhood (4.0–4.6% at the age of 8–10) grow fast by the age of 11–12, reaching a peak of 6.2% in the interval of 11–12 years. This is followed by a sharp decline: the gains gradually reduce to 3.2–3.8% at the age of 12–14, 2.4% at 14–15, 1.8% at 15–16 and 0.6% at 16–17, forming the downward line of the puberty wave and the start of the plateau of the final growth.

In the Khanty group, the histogram curve in the second childhood period was less steep: the gains were 4.1–4.4% at the age of 8–12, without such a sharp peak as the newcomer group had. In the adolescent age, there is observed a gradual rise to 4.8% at the age of 13–14, after which the growth rate decreases to 2.9% at 15–16 years of age and 1.2% at the age of 16–17, i.e. the maximum gain shifts approx. 1–1.5 years later and is less manifested.

Based on the aggregate data presented in Tables 1–5, it was established that in boys from both studied populations, body length increases continuously from birth to 17 years of age; however, the trajectories of this process differ substantially in terms of both absolute values and temporal organization. By the end of the first year of life, the mean body length of boys from the newcomer population consistently exceeded the corresponding values in the SIPN group, with the interpopulation gap showing a tendency to widen and reaching its maximum during the second childhood and pubertal periods.

The graphic analysis of relative gains of growth (Figs. 1–4) presents a three-phase post-natal growth structure characteristic of humans: a fast decrease of growth rates in the infancy and early childhood periods, an almost linear phase in the period of the first and partially second childhood periods, and a marked increase of growth gains in the pre-puberty and early puberty periods. In the newcomer group? The raise of the growth rate curve starts as early as at the age of 10–11 reaching a peak at 11–12 years, after which the growth rates decrease quickly by the age of 15–17. In the SIPN population, the increase of growth rates is more extended, the maximum of 4.4–4.8% occurring at the age of 11–14, and the decrease of growth rates is marked only after 15 years of age, showing the shift of the peak growth rate to a later age interval (around 13 years of age) and a prolonged growth during puberty.

Throughout the entire observation period, the mean growth curves of the two populations did not intersect: from 21 months of age onward, body length in boys from the newcomer population was statistically significantly greater than that in the SIPN group, and this superiority persisted until the completion of adolescent growth.

Overall, the obtained data indicate that boys from the newcomer population residing in the Middle Ob region are characterized by higher mean growth parameters at all stages of postnatal ontogenesis, earlier and more intensive pubertal growth acceleration, and greater interindividual variability in final body dimensions compared with their SIPN peers. In contrast, the Khanty boys typically exhibit somewhat smaller absolute body dimensions, more moderate growth rates during the preschool period, and a later and less pronounced pubertal growth spurt, which accounts for a sustained, statistically significant interpopulation difference in body length by the time of completion of adolescent development.

CONCLUSION

Analysis of the obtained data revealed persistent differences in boys from the newcomer population compared with the indigenous small-numbered population of the Middle Ob region during the period of postnatal ontogenesis. The interpopulation gap in body length emerges as early as the second year of life and exhibits a sustained tendency to widen. The maximum absolute difference is attained during the second childhood and pubertal periods, decreasing somewhat by 17 years of age due to the later completion of growth in the Khanty boys. The observed differences are likely the result of a complex interplay between ethnogenetic adaptations and environmental factors. The later and more prolonged pubertal period in the Khanty boys may be characterized as reflecting the influence of traditional living conditions in northern latitudes.

 

ADDITIONAL INFORMATION	ДОПОЛНИТЕЛЬНАЯ ИНФОРМАЦИЯ
Ethical review. The study was approved by the Ethics Committee of the Tyumen State Medical University (protocol No. 130 dated June 7, 2025).	Этическая экспертиза. Проведение исследования одобрено комитетом по этике ФГБОУ ВО Тюменский ГМУ (протокол №130 от 07 июня 2025 г.).
Informed consent. All legal guardians (parents) signed voluntary informed consent for the children's participation in the study.	Информированное согласие. Все законные представители (родители) подписали добровольное информированное согласие на участие детей в исследовании.
Study funding. The study was the authors' initiative without external funding.	Источник финансирования. Работа выполнена по инициативе авторов без привлечения финансирования.
Conflict of interest. The authors declare that there are no obvious or potential conflicts of interest associated with the content of this article.	Конфликт интересов. Авторы декларируют отсутствие явных и потенциальных конфликтов интересов, связанных с содержанием настоящей статьи.
Contribution of individual authors. Margaryan A.V., Vikhareva L.V.: study idea and design, writing and editing of the manuscript. Maltseva N.G.: statistical data processing. Baitrak O.A., Yaroslavtseva O.F.: experiments, data collection, creation of graphs and tables. The authors gave their final approval of the manuscript for submission, and agreed to be accountable for all aspects of the work, implying proper study and resolution of issues related to the accuracy or integrity of any part of the work.	Участие авторов. Маргарян А.В., Вихарева Л.В.: идея и дизайн исследования, написание и редактирование текста рукописи. Мальцева Н.Г.: статистическая обработка данных. Байтрак О.А., Ярославцева О.Ф.: проведение экспериментов, сбор данных, создание графиков, таблиц. Все авторы одобрили финальную версию статьи перед публикацией, выразили согласие нести ответственность за все аспекты работы, подразумевающую надлежащее изучение и решение вопросов, связанных с точностью или добросовестностью любой части работы.
Statement of originality. No previously published material (text, images, or data) was used in this work.	Оригинальность. При создании настоящей работы авторы не использовали ранее опубликованные сведения (текст, иллюстрации, данные).
Data availability statement. The editorial policy regarding data sharing does not apply to this work.	Доступ к данным. Редакционная политика в отношении совместного использования данных к настоящей работе не применима.
Generative AI. No generative artificial intelligence technologies were used to prepare this article.	Генеративный искусственный интеллект. При создании настоящей статьи технологии генеративного искусственного интеллекта не использовали.
Provenance and peer review. This paper was submitted unsolicited and reviewed following the standard procedure. The peer review process involved 2 external reviewers.	Рассмотрение и рецензирование. Настоящая работа подана в журнал в инициативном порядке и рассмотрена по обычной процедуре. В рецензировании участвовали 2 внешних рецензента.

About the authors

A. V. Margaryan

Tyumen State Medical University

Email: vanic13@mail.ru
ORCID iD: 0000-0003-3497-8157

MD, Dr. Sci. (Medicine), Professor of the Department of Topographic Anatomy and Operative Surgery

Russian Federation, Tyumen

O. A. Baitrak

Surgut District Polyclinic

Author for correspondence.
Email: voa-88@mail.ru
ORCID iD: 0009-0002-2831-416X

Pediatrician of the Department for Providing Medical Care to Children of Educational Institutions

Russian Federation, Bely Yar

L. V. Vikhareva

Tyumen State Medical University

Email: vikharevalv@yandex.ru
ORCID iD: 0000-0001-6864-4417

MD, Dr. Sci. (Medicine), Professor of the Department of Topographic Anatomy and Operative Surgery

Russian Federation, Tyumen

N. G. Maltseva

Tyumen State Medical University

Email: malcevang@tyumsmu.ru
ORCID iD: 0009-0001-8792-0541

MD, Cand. Sci. (Medicine), Associate Professor of the Department of Topographic Anatomy and Operative Surgery

Russian Federation, Tyumen

O. F. Yaroslavtseva

Tyumen State Medical University

Email: yaroslavtseva@tyumsmu.ru
ORCID iD: 0009-0008-3854-3170

MD, Cand. Sci. (Medicine), Associate Professor of the Department of Topographic Anatomy and Operative Surgery

Russian Federation, Tyumen

References

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