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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Russian Medicine</journal-id><journal-title-group><journal-title xml:lang="en">Russian Medicine</journal-title><trans-title-group xml:lang="ru"><trans-title>Российский медицинский журнал</trans-title></trans-title-group></journal-title-group><issn publication-format="print">0869-2106</issn><issn publication-format="electronic">2412-9100</issn><publisher><publisher-name xml:lang="en">Eco-Vector</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">698654</article-id><article-id pub-id-type="doi">10.17816/medjrf698654</article-id><article-id pub-id-type="edn">RCEKKN</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Original Research Articles</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Оригинальные исследования</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Neural network modeling of the association of climate and non-contact injury with serum immunoglobulin A concentration in elite athletes: a retrospective cohort study</article-title><trans-title-group xml:lang="ru"><trans-title>Нейросетевое моделирование ассоциации климата и неконтактного травматизма с концентрацией сывороточного иммуноглобулина A у спортсменов высокого класса: ретроспективное когортное исследование</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-4073-475X</contrib-id><contrib-id contrib-id-type="spin">2806-6159</contrib-id><name-alternatives><name xml:lang="en"><surname>Buyanova</surname><given-names>Natalia M.</given-names></name><name xml:lang="ru"><surname>Буянова</surname><given-names>Наталья Михайловна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD</p></bio><email>dpo.mkramn@inbox.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-3632-291X</contrib-id><contrib-id contrib-id-type="spin">3370-2093</contrib-id><name-alternatives><name xml:lang="en"><surname>Kochetov</surname><given-names>Anatoly G.</given-names></name><name xml:lang="ru"><surname>Кочетов</surname><given-names>Анатолий Глебович</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Dr. Sci. (Medicine), Professor</p></bio><bio xml:lang="ru"><p>д-р мед. наук, профессор</p></bio><email>kochetov.lab@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-2233-7301</contrib-id><contrib-id contrib-id-type="spin">2609-0174</contrib-id><name-alternatives><name xml:lang="en"><surname>Alpatov</surname><given-names>Sergey P.</given-names></name><name xml:lang="ru"><surname>Алпатов</surname><given-names>Сергей Петрович</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Cand. Sci. (Medicine)</p></bio><bio xml:lang="ru"><p>канд. мед. наук</p></bio><email>immunosport@rambler.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-5429-9528</contrib-id><contrib-id contrib-id-type="spin">8453-9166</contrib-id><name-alternatives><name xml:lang="en"><surname>Romanov</surname><given-names>Boris K.</given-names></name><name xml:lang="ru"><surname>Романов</surname><given-names>Борис Константинович</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Dr. Sci. (Medicine), Associate Professor</p></bio><bio xml:lang="ru"><p>д-р мед. наук, доцент</p></bio><email>romanov_bk@rsmu.ru</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">The Russian National Research Medical University named after N.I. Pirogov</institution></aff><aff><institution xml:lang="ru">Российский национальный исследовательский медицинский университет имени Н.И. Пирогова</institution></aff></aff-alternatives><pub-date date-type="preprint" iso-8601-date="2026-04-29" publication-format="electronic"><day>29</day><month>04</month><year>2026</year></pub-date><pub-date date-type="pub" iso-8601-date="2026-05-12" publication-format="electronic"><day>12</day><month>05</month><year>2026</year></pub-date><volume>32</volume><issue>2</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>111</fpage><lpage>123</lpage><history><date date-type="received" iso-8601-date="2025-12-15"><day>15</day><month>12</month><year>2025</year></date><date date-type="accepted" iso-8601-date="2026-01-20"><day>20</day><month>01</month><year>2026</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2026, Eco-Vector</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2026, Эко-Вектор</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="en">Eco-Vector</copyright-holder><copyright-holder xml:lang="ru">Эко-Вектор</copyright-holder><ali:free_to_read xmlns:ali="http://www.niso.org/schemas/ali/1.0/" start_date="2029-05-12"/><license><ali:license_ref xmlns:ali="http://www.niso.org/schemas/ali/1.0/">https://eco-vector.com/for_authors.php#07</ali:license_ref></license></permissions><self-uri xlink:href="https://medjrf.com/0869-2106/article/view/698654">https://medjrf.com/0869-2106/article/view/698654</self-uri><abstract xml:lang="en"><p><bold>BACKGROUND:<italic> </italic></bold>The role of serum immunoglobulin A is often underestimated; however, its functions in systemic protection and endotoxin clearance make it an important marker of the “cost of adaptation.” Serum immunoglobulin A concentration depends on sex and age, but the influence of contrast climate and the specifics of non-contact injury during the off-season has not been thoroughly studied before.</p> <p><bold>AIM:<italic> </italic></bold>To assess the influence of climatic factors and the specifics of non-contact injury on the variability of serum immunoglobulin A levels, taking into account age and sex, in elite athletes during the off-season.</p> <p><bold>METHODS:<italic> </italic></bold>A retrospective analysis of data from 7549 athletes (mean age 19.98 years) was performed. Comparative pairs were formed: “Biathlon–Triathlon” (climate influence with similar energy expenditure) and “Figure Skating–Speed Skating” (influence of biomechanics and injury patterns). Serum immunoglobulin A levels were measured using immunochemiluminescence analysis (g/L). Statistical analysis included estimation of 95% confidence intervals and neural network modeling (multilayer perceptron) to assess the contribution of factors.</p> <p><bold>RESULTS:<italic> </italic></bold>Reduced serum IgA levels were observed in athletes participating in winter and impact-loading sports. In biathletes, the level (1.67 g/L) was lower than in triathletes (1.73 g/L); the weight of the cold factor was –0.443. The minimum value was recorded in figure skating (1.40 g/L), which was significantly lower than that in speed skating (1.68 g/L). Modeling showed that impact loads (weight: –0.548) were associated with a lower level of serum immunoglobulin A. Sexual dimorphism (males &gt; females) and positive age-related trends were confirmed.</p> <p><bold>CONCLUSION:<italic> </italic></bold>Serum immunoglobulin A serves as a sensitive integrated marker of allostatic load. Cold stress and chronic trauma resulting from impact loads act as independent factors contributing to its reduction. The risk group includes female and young athletes specializing in complex coordination and winter sports.</p></abstract><trans-abstract xml:lang="ru"><p><bold>Обоснование. </bold>Роль сывороточного иммуноглобулина А часто недооценивается, однако функции системной защиты и клиренса эндотоксинов делают его важным маркером «цены адаптации». Концентрация показателя зависит от пола и возраста, но влияние контрастного климата и специфики неконтактного травматизма в межсоревновательный период ранее детально не изучалось.</p> <p><bold>Цель. </bold>Оценить влияние климатических факторов и специфики неконтактного травматизма на вариабельность концентрации сывороточного иммуноглобулина А с учётом возраста и пола у спортсменов высокой квалификации в межсоревновательный период.</p> <p><bold>Методы. </bold>Проведён ретроспективный анализ данных 7549 спортсменов (средний возраст 19,98 года). Сформированы пары сравнения: «биатлон–триатлон» (влияние климата при схожем энергообеспечении) и «фигурное катание–конькобежный спорт» (влияние биомеханики и травматизма). Концентрацию сывороточного иммуноглобулина А измеряли методом иммунохемилюминесценции (г/л). Статистический анализ включал оценку 95% доверительных интервалов и нейросетевое моделирование (многослойный перцептрон) для оценки вклада факторов.</p> <p><bold>Результаты. </bold>Установлено снижение концентрации сывороточного иммуноглобулина А у представителей зимних и сопряжённых с ударной нагрузкой видов спорта. У биатлонистов она ниже (1,67 г/л), чем у триатлонистов (1,73 г/л); вес холодового фактора составил −0,443. В фигурном катании зафиксирован минимум (1,40 г/л), что значимо ниже конькобежного спорта (1,68 г/л). Моделирование показало, что ударные нагрузки (вес −0,548) ассоциируются с более низкой концентрацией сывороточного иммуноглобулина А. Подтверждены половой диморфизм (мужчины &gt; женщины) и положительная возрастная динамика.</p> <p><bold>Заключение. </bold>Сывороточный иммуноглобулин А служит чувствительным интегральным маркером аллостатической нагрузки. Холодовой стресс и хроническая травматизация ударными нагрузками выступают независимыми факторами снижения его концентрации. В группе риска находятся женщины и юные спортсмены, специализирующиеся в сложнокоординационных и зимних видах спорта.</p></trans-abstract><kwd-group xml:lang="en"><kwd>serum immunoglobulin A</kwd><kwd>sports immunology</kwd><kwd>neural network modelling</kwd><kwd>cold stress</kwd><kwd>sports traumatism</kwd><kwd>adaptation</kwd><kwd>elite athletes</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>сывороточный иммуноглобулин А</kwd><kwd>спортивная иммунология</kwd><kwd>нейросетевое моделирование</kwd><kwd>холодовой стресс</kwd><kwd>спортивный травматизм</kwd><kwd>адаптация</kwd><kwd>элитные спортсмены</kwd></kwd-group><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Davis SK, Selva KJ, Kent SJ, Chung AW. Serum IgA Fc effector functions in infectious disease and cancer. Immunol Cell Biol. 2020;98(4):276–286. doi: 10.1111/imcb.12306 EDN: MQEZXW</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Alpatov SP, Rygalov MA, Podlivaev BA, et al. Feteatures of the dynamics high qualification wrestlers serum levels of immunoglobulin a in the immunomodulating therapy. Russian Journal of Immunology. 2013;7(4):403–411. EDN: SVZMXP</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Alpatov SP, Buyanova NM, Efimov PV, et al. Immunoglobulin A: actualization of medical aspects of the problem in sports. Lechebnaya fizkul’tura i sportivnaya medicina. 2024;(2):15–24. EDN: AUKYLI</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Khan SR, van der Burgh AC, Peeters RP, et al. Determinants of serum immunoglobulin levels: a systematic review and meta-analysis. Front Immunol. 2021;12:664526. doi: 10.3389/fimmu.2021.66452 EDN: NHTPWW</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Steffen U, Koeleman CA, Sokolova MV, et al. IgA subclasses have different effector functions associated with distinct glycosylation profiles. Nat Commun. 2020;11(1):120. doi: 10.1038/s41467-019-13992-8 EDN: RVBGYH</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Buyanova NM, Alpatov SP, Kochetov AG, et al. Comparative analysis of serum immunoglobul in a concentrations byolympic classification and level of athletic achievement in elite athletes. Clinical Laboratory Diagnostics. 2024;69(12):665–671 doi: 10.51620/0869-2084-2024-69-12-665-671 EDN: BBCTYL</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Pires W, Veneroso CE, Wanner SP, et al. Association between exercise-induced hyperthermia and intestinal permeability: a systematic review. Sports Med. 2017;47(7):1389–1403. doi: 10.1007/s40279-016-0654-2 EDN: OLEJJB</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Hansen IS, Baeten DL, den Dunnen J. The inflammatory function of human IgA. Cellular and Molecular Life Sciences. 2019;76(6):1041–1055. doi: 10.1007/s00018-018-2976-8 EDN: JPAFRT</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Simpson RJ, Campbell JP, Gleeson M, et al. Can exercise affect immune function to increase susceptibility to infection? Exerc Immunol Rev. 2020;26:8–22.</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Nieman DC. Exercise, infection, and immunity. Int J Sports Med. 1994;15 Suppl. 3:131–141. doi: 10.1055/s-2007-1021128</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Walzik D, Belen S, Wilisch K, et al. Impact of exercise on markers of B cell-related immunity: A systematic review. J Sport Health Sci. 2024;13(3):339–352. doi: 10.1016/j.jshs.2023.10.002 EDN: HEUOVB</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Moesgaard L, Beck MM, Christiansen L, et al. Effects of periodization on strength and muscle hypertrophy in volume-equated resistance training programs: a systematic review and meta-analysis. Sports Med. 2022;52(7):1647–1666. doi: 10.1007/s40279-021-01636-1 EDN: NBMABK</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Baskerville R, Castell L, Bermon S. Sports and immunity, from the recreational to the elite athlete. Infect Dis Now. 2024;54(4S):104893. doi: 10.1016/j.idnow.2024.104893 EDN: MRPNGG</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Kurowski M, Seys S, Bonini M, et al. Physical exercise, immune response, and susceptibility to infections-current knowledge and growing research areas. Allergy. 2022;77(9):2653–2664. doi: 10.1111/all.15328 EDN: JBMHKT</mixed-citation></ref><ref id="B15"><label>15.</label><mixed-citation>Jesuthasan A, Ali A, Lee JKW, Rutherfurd-Markwick K. Assessment of changes in physiological markers in different body fluids at rest and after exercise. Nutrients. 2022;14(21):4685. doi: 10.3390/nu14214685 EDN: FFEHJN</mixed-citation></ref><ref id="B16"><label>16.</label><mixed-citation>Jaeger E, Maurer DJ, Wallimann A, et al. Immunity, inflammation and airway dysfunction in elite cross-country skiers and ice hockey players: a systematic review. Scand J Med Sci Sports. 2025;35(4):e70046. doi: 10.1111/sms.70046 EDN: PLKLLT</mixed-citation></ref><ref id="B17"><label>17.</label><mixed-citation>Novikova NB, Ivanova IG, Sergeev GA, et al. Skate skiing techniques in cross-country races and biathlon: comparative analysis. Teoriya i pracktika fizicheskoy kultury. 2021;(12):33–35. doi: 10.24412/0040-3601-2021-12-33-35 EDN: GHJENJ</mixed-citation></ref><ref id="B18"><label>18.</label><mixed-citation>Bumarskova NN, Nikishkin VA. Injuries in figure skating. Uchenye zapiski universiteta imeni P.F. Lesgafta. 2020;2(180):63–68. doi: 10.34835/issn.2308-1961.2020.2.p63-68 EDN: HICAGT</mixed-citation></ref><ref id="B19"><label>19.</label><mixed-citation>Van de Water ATM, Hendricks M. First steps towards prevention of musculoskeletal injuries in speed skating. In: IOC World Conference on Prevention of Injury and Illness in Sport. Monaco; 2017. doi: 10.1136/bjsports-2016-097372.297</mixed-citation></ref><ref id="B20"><label>20.</label><mixed-citation>Khan SR, Chaker L, Ikram MA, et al. Determinants and reference ranges of serum immunoglobulins in middle-aged and elderly individuals: a population-based study. J Clin Immunol. 2021;41(8):1902–1914. doi: 10.1007/s10875-021-01120-5 EDN: LHEKQO</mixed-citation></ref><ref id="B21"><label>21.</label><mixed-citation>Assis SB, Slhessarenko N, Fontes CJF. Reference intervals for serum immunoglobulin A levels in Brazilian children aged 1 to 10 years: a population-based study. J Pediatr (Rio J). 2023;99(5):492–499. doi: 10.1016/j.jped.2023.03.007 EDN: BZFIEW</mixed-citation></ref></ref-list></back></article>
