problendoПроблемы ЭндокринологииProblems of Endocrinology0375-96602308-1430Endocrinology Research Centre10.14341/probl13250problendo-13250Research ArticleДетская эндокринологияPediatric EndocrinologyАдипомиокины у детей с конституционально-экзогенным ожирениемAdipomyokines in children with obesityhttps://orcid.org/0000-0002-2974-667XБурмицкаяЮ. В.BurmitskayaYu. V.

Бурмицкая Юлия Вадимовна

Россия, 117036, ул. Дмитрия Ульянова, д. 11 

Yulia V. Burmitskaya, MD 

11 Dm. Ulyanova street, 117036 Moscow, Russia 

yulia839@yandex.ruhttps://orcid.org/0000-0002-9299-1053ВасюковаО. В.VasyukovaO. V.

Васюкова Ольга Владимировна, к.м.н. 

Россия, 117036, ул. Дмитрия Ульянова, д. 11 

Olga V. Vasyukova, MD, PhD 

11 Dm. Ulyanova street, 117036 Moscow, Russia 

o.vasyukova@mail.ruhttps://orcid.org/0000-0001-9834-727XОкороковП. Л.OkorokovP. L.

Окороков Павел Леонидович, к.м.н. 

Россия, 117036, ул. Дмитрия Ульянова, д. 11 

Pavel L. Okorokov, MD, PhD 

11 Dm. Ulyanova street, 117036 Moscow, Russia 

pokorokov@gmail.comhttps://orcid.org/0000-0001-6953-6928ЗураеваЗ. Т.ZuraevaZ. T.

Зураева Замира Тотразовна  

Россия, 117036, ул. Дмитрия Ульянова, д. 11 

Zamira T. Zuraeva, MD 

11 Dm. Ulyanova street, 117036 Moscow, Russia 

zuraeva_zamira@mail.ruhttps://orcid.org/0000-0001-9621-5732БезлепкинаО. Б.BezlepkinaO. B.

Безлепкина Ольга Борисовна, д.м.н., профессор 

Россия, 117036, ул. Дмитрия Ульянова, д. 11 

Olga B. Bezlepkina, MD, PhD, Professor

11 Dm. Ulyanova street, 117036 Moscow, Russia 

olgabezlepkina@mail.ruНациональный медицинский исследовательский центр эндокринологииРоссияEndocrinology Research CenterRussian Federation2023300820236948795Copyright © Бурмицкая Ю.В., Васюкова О.В., Окороков П.Л., Зураева З.Т., Безлепкина О.Б., 20232023Бурмицкая Ю.В., Васюкова О.В., Окороков П.Л., Зураева З.Т., Безлепкина О.Б.Burmitskaya Y.V., Vasyukova O.V., Okorokov P.L., Zuraeva Z.T., Bezlepkina O.B.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.probl-endojournals.ru/jour/article/view/13250

ОБОСНОВАНИЕ. Адипомиокины синтезируются и секретируются в кровоток клетками как мышечной, так и жировой ткани. Они могут оказывать как отрицательное метаболическое воздействие, выступая в роли провоспалительных адипокинов при ожирении, так и положительное, повышаясь в ответ на физические нагрузки в виде миокинов.ЦЕЛЬ. Изучить особенности секреции адипомиокинов у детей с конституционально-экзогенным ожирением.МАТЕРИАЛЫ И МЕТОДЫ. В исследование включены 80 пациентов: 60 подростков 15 [13; 16] лет с конституционально-экзогенным ожирением, SDS индекса массы тела (ИМТ): 3,0 [2,6; 3,3], и 20 детей группы контроля 16 [15; 17] лет без избытка массы тела, SDS ИМТ: -0,3 [-1,25; 0,33]. Для определения уровня адипомиокинов использованы коммерческие наборы для иммуноферментного анализа. Композиционный состав тела оценивался методом биоимпедансного анализа (анализатор In Body 770, Южная Корея) утром, натощак. Статистическая обработка проводилась с применением STATISTICA v.12.0 (StatSoftInc., США). Результаты представлены в виде медианы (Ме) и квартилей (Q1; Q3), соответствующих 25 и 75 перцентилям. Критический уровень значимости (р) принимали равным <0,05.РЕЗУЛЬТАТЫ. Уровни интерлейкина-6 (ИЛ-6) и ирисина статистически значимо выше у подростков с ожирением по сравнению с группой контроля: 0,55 [0,226; 1,35] vs 0,202 [0,128; 0,652] пг/мл (р=0,041) и 11,16 [6,6; 22,76] vs 7,36 [6,48; 9,68] мкг/мл (р=0,043) соответственно. Концентрации ИЛ-6, миостатина и декорина повышаются при увеличении степени ожирения: I степень vs III: 0,226 [0,224; 0,398] vs 0,80 [0,36; 1,81] пг/мл (р=0,0197), 25,85 [21,53; 28,23] vs 31,41 [24,36; 35,06] нг/мл (р=0,03), 4065,3 [3244,9; 5245,5] vs 5322,5 [4199,8; 7702,4] пг/мл (р=0,0376) соответственно. У детей с ожирением уровни ИЛ-6 положительно коррелируют с ИМТ, SDS ИМТ и количеством жировой ткани, а миостатина — с ИМТ и SDS ИМТ. Концентрация ирисина в сыворотке крови значимо выше у девочек с ожирением, чем у мальчиков с ожирением и здоровых девочек. Пациенты с ожирением, по сравнению с худыми сверстниками, характеризуются статистически значимо большим содержанием как жировой, так и тощей массы. При прогрессировании ожирения отмечается статистически значимое повышение отношения жировой к тощей массе (I степень — 0,66 [0,56; 0,7], III — 0,78 [0,68; 0,98]; р=0,0073).ЗАКЛЮЧЕНИЕ. Пациенты с ожирением и нормальной массой тела имеют различные уровни адипомиокинов. Повышение уровня ИЛ-6 при прогрессировании ожирения напрямую связано с увеличением содержания жировой ткани. Требуется дальнейшее изучение особенностей секреции адипомиокинов, их взаимосвязи с композиционным составом тела и метаболическими осложнениями при ожирении.

BACKGROUND: Adipomyokines are synthesized and secreted into the bloodstream by cells of both muscle and adipose tissue. They can have both a negative metabolic effect, acting as pro-inflammatory adipokines in obesity, and a positive one, increasing in response to physical exertion in the form of myokines.AIM: To study the features of adipocytokine secretion in children with constitutionally exogenous obesity.MATERIALS AND METHODS: The study included 80 patients: 60 adolescents aged 15 [13; 16] years with constitutionally exogenous obesity SDS BMI: 3.0 [2.6; 3.3] and 20 control group children aged 16 [15; 17] years without excess weight SDS BMI: -0.3 [-1.25; 0.33]. Commercial enzyme immunoassay kits were used to determine the level of adipomyokines. The compositional composition of the body was evaluated by bioimpedance analysis (InBody 770 analyzer, South Korea) in the morning, on an empty stomach. Statistical processing was carried out using STATISTICA v.12.0 (StatSoft Inc., USA). The results are presented in the form of median (Me) and quartiles (Q1; Q3) corresponding to 25 and 75 percentiles. The critical significance level (p) was assumed to be <0.05.RESULTS: Levels of IL-6 and irisin are statistically significantly higher in obese adolescents compared to the control group: 0.55 [0.226; 1.35] pg/ml vs 0.202 [0.128; 0.652] pg/ml (p=0.041) and 11.16 [6.6; 22.76] mcg/ml vs 7.36 [6.48; 9.68] mcg/ml (p=0.043), respectively. Concentrations of IL-6, myostatin and decorin increase with an increase in the degree of obesity: grade I vs III: 0.226 [0.224; 0.398] vs 0.80 [0.36; 1.81] pg/ml (p=0,0197), 25,85 [21,53; 28,23] vs 31.41 [24.36; 35.06] ng/ml (p=0.03), 4065.3 [3244.9; 5245.5] vs 5322.5 [4199.8; 7702.4] pg/ml (p=0.0376), respectively. In obese children, IL-6 levels positively correlate with BMI, SDS BMI and the amount of adipose tissue, and myostatin — with BMI and SDS BMI. The concentration of irisin in the blood serum is significantly higher in obese girls than in obese boys and healthy girls. Obese patients, compared with lean peers, are characterized by a statistically significantly higher content of both fat and lean mass. With the progression of obesity, there is a statistically significant increase in the ratio of fat to lean mass (I degree — 0.66 [0.56; 0.7], III — 0.78 [0.68; 0.98] (p=0.0073).CONCLUSION: Patients with obesity and normal body weight have different levels of adipomyokines. An increase in the level of IL-6 with the progression of obesity is directly related to an increase in the content of adipose tissue. Further study of the features of adipocytokine secretion, their relationship with the features of the body composition and metabolic complications in obesity is required.

миокиныадипомиокиныожирениедетиподросткиинтерлейкин-6миостатиндекоринирисинбиоимпедансометрияmyokinesadipomyokinesobesitychildrenadolescentsinterleukin-6myostatindecorinirisinbioimpedanceПубликация подготовлена в рамках госзадания «Новые подходы к персонифицированному лечению ожирения у детей на основе исследований энергетического обмена, функционального резерва бета-клеток, секреции адипокинов, миокинов и специфических шаперонов», регистрационный номер АААА-А20-120011790172-9.ReferencesPedersen BK, Steensberg A, Fischer C, et al. Searching for the exercise factor: is IL-6 a candidate? J Muscle Res Cell Motil. 2003;24(2-3):113-119. doi: https://doi.org/10.1023/a:1026070911202Pedersen BK, Steensberg A, Fischer C, et al. Searching for the exercise factor: is IL-6 a candidate? J Muscle Res Cell Motil. 2003;24(2-3):113-119. doi: https://doi.org/10.1023/a:1026070911202Severinsen MCK, Pedersen BK. Muscle–organ crosstalk: The emerging roles of myokines. Endocr Rev. 2020;41(4):594-609. doi: https://doi.org/10.1210/endrev/bnaa016Severinsen MCK, Pedersen BK. Muscle–organ crosstalk: The emerging roles of myokines. Endocr Rev. 2020;41(4):594-609. doi: https://doi.org/10.1210/endrev/bnaa016Петеркова В.А., Безлепкина О.Б., Болотова Н.В., и др. Клинические рекомендации «Ожирение у детей» // Проблемы эндокринологии. — 2021. — Т. 67. — №5. — С. 67-83. doi: https://doi.org/10.14341/probl12802Peterkova VA, Bezlepkina OB, Bolotova NV, et al. Clinical guidelines «Obesity in children». Problems of Endocrinology. 2021;67(5):67-83. (In Russ.). doi: https://doi.org/10.14341/probl12802Gätjens I, Schmidt SCE, Plachta-Danielzik S, et al. Body composition characteristics of a load-capacity model: Age-dependent and sex-specific percentiles in 5- to 17-year-old children. Obes Facts. 2021;14(6):593-603. doi: https://doi.org/10.1159/000518638Gätjens I, Schmidt SCE, Plachta-Danielzik S, et al. Body composition characteristics of a load-capacity model: Age-dependent and sex-specific percentiles in 5- to 17-year-old children. Obes Facts. 2021;14(6):593-603. doi: https://doi.org/10.1159/000518638Choi KM. Sarcopenia and sarcopenic obesity. Korean J Intern Med. 2016;31(6):1054-1060. doi: https://doi.org/10.3904/kjim.2016.193Choi KM. Sarcopenia and sarcopenic obesity. Korean J Intern Med. 2016;31(6):1054-1060. doi: https://doi.org/10.3904/kjim.2016.193Окороков П.Л., Васюкова О.В. Особенности композиционного состава тела и основного обмена у подростков с морбидным ожирением // Педиатрия им. Г.Н. Сперанского. — 2021. — Т. 100. — №4. — С. 216-221.Okorokov PL, Vasyukova OV. Features of body composition and basal metabolic rate in adolescents with morbid obesity. Pediatria n.a. G.N. Speransky. 2021;100(4):216-221. (In Russ.).Окороков П.Л., Васюкова О.В., Безлепкина О.Б. Распространенность «саркопенического ожирения» у детей с конституционально-экзогенным ожирением // Педиатрия им. Г.Н. Сперанского. — 2022. — Т. 101. — №5. — С. 43-49. doi: https://doi.org/10.24110/0031-403X-2022-101-5-43-49Okorokov PL, Vasyukova OV, Bezlepkina OB. Sarcopenic obesity prevalence in children with constitutional-exogenous obesity. Pediatria n.a. G.N. Speransky. 2022;101(5):43-49. (In Russ.). doi: https://doi.org/10.24110/0031-403X-2022-101-5-43-49Luciardi MC, Carrizo TR, Díaz EI, et al. Estado proinflamatorio en niños obesos [Proinflammatory state in obese children]. Rev Chil Pediatr. 2018;89(3):346-351. doi: https://doi.org/10.4067/S0370-41062018005000501Luciardi MC, Carrizo TR, Díaz EI, et al. Estado proinflamatorio en niños obesos [Proinflammatory state in obese children]. Rev Chil Pediatr. 2018;89(3):346-351. doi: https://doi.org/10.4067/S0370-41062018005000501Hosick P, McMurray R, Hackney AC, et al. Resting IL-6 and TNF-α level in children of different weight and fitness status. Pediatr Exerc Sci. 2013;25(2):238-247. doi: https://doi.org/10.1123/pes.25.2.238Hosick P, McMurray R, Hackney AC, et al. Resting IL-6 and TNF-α level in children of different weight and fitness status. Pediatr Exerc Sci. 2013;25(2):238-247. doi: https://doi.org/10.1123/pes.25.2.238Pîrsean C, Neguț C, Stefan-van Staden RI, et al. The salivary levels of leptin and interleukin-6 as potential inflammatory markers in children obesity. PLoS One. 2019;14(1):e0210288. doi: https://doi.org/10.1371/journal.pone.0210288Pîrsean C, Neguț C, Stefan-van Staden RI, et al. The salivary levels of leptin and interleukin-6 as potential inflammatory markers in children obesity. PLoS One. 2019;14(1):e0210288. doi: https://doi.org/10.1371/journal.pone.0210288Tam CS, Garnett SP, Cowell CT, et al. IL-6, IL-8 and IL-10 levels in healthy weight and overweight children. Horm Res Paediatr. 2010;73(2):128-134. doi: https://doi.org/10.1159/000277632Tam CS, Garnett SP, Cowell CT, et al. IL-6, IL-8 and IL-10 levels in healthy weight and overweight children. Horm Res Paediatr. 2010;73(2):128-134. doi: https://doi.org/10.1159/000277632El-Mikkawy DME, EL-Sadek MA, EL-Badawy MA, Samaha D. Circulating level of interleukin-6 in relation to body mass indices and lipid profile in Egyptian adults with overweight and obesity. Egypt Rheumatol Rehabil. 2020;47(1):7. doi: https://doi.org/10.1186/s43166-020-00003-8El-Mikkawy DME, EL-Sadek MA, EL-Badawy MA, Samaha D. Circulating level of interleukin-6 in relation to body mass indices and lipid profile in Egyptian adults with overweight and obesity. Egypt Rheumatol Rehabil. 2020;47(1):7. doi: https://doi.org/10.1186/s43166-020-00003-8Khaodhiar L, Ling P-R, Blackburn GL, Bistrian BR. Serum levels of Interleukin-6 and C-reactive protein correlate with body mass index across the broad range of obesity. J Parenter Enter Nutr. 2004;28(6):410-415. doi: https://doi.org/10.1177/0148607104028006410Khaodhiar L, Ling P-R, Blackburn GL, Bistrian BR. Serum levels of Interleukin-6 and C-reactive protein correlate with body mass index across the broad range of obesity. J Parenter Enter Nutr. 2004;28(6):410-415. doi: https://doi.org/10.1177/0148607104028006410Baikpour M, Baikpour M, Hosseini M, Sarveazad A. Variations in levels of interleukins and adiponectin in normal and obese adults; a case-control study. J Med Physiol. 2017; 2(2):56-62. [cited 20.07.2023]. Available from: http://jphysiology.com/index.php/jmp/article/view/29Baikpour M, Baikpour M, Hosseini M, Sarveazad A. Variations in levels of interleukins and adiponectin in normal and obese adults; a case-control study. J Med Physiol. 2017; 2(2):56-62. [cited 20.07.2023]. Available from: http://jphysiology.com/index.php/jmp/article/view/29Roytblat L, Rachinsky M, Fisher A, et al. Raised interleukin-6 levels in obese patients. Obes Res. 2000;8(9):673-675. doi: https://doi.org/10.1038/oby.2000.86Roytblat L, Rachinsky M, Fisher A, et al. Raised interleukin-6 levels in obese patients. Obes Res. 2000;8(9):673-675. doi: https://doi.org/10.1038/oby.2000.86Hittel DS, Berggren JR, Shearer J, et al. Increased secretion and expression of myostatin in skeletal muscle from extremely obese women. Diabetes. 2009;58(1):30-38. doi: https://doi.org/10.2337/db08-0943Hittel DS, Berggren JR, Shearer J, et al. Increased secretion and expression of myostatin in skeletal muscle from extremely obese women. Diabetes. 2009;58(1):30-38. doi: https://doi.org/10.2337/db08-0943Milan G, Dalla Nora E, Pilon C, et al. Changes in muscle myostatin expression in obese subjects after weight loss. J Clin Endocrinol Metab. 2004;89(6):2724-2727. doi: https://doi.org/10.1210/jc.2003-032047Milan G, Dalla Nora E, Pilon C, et al. Changes in muscle myostatin expression in obese subjects after weight loss. J Clin Endocrinol Metab. 2004;89(6):2724-2727. doi: https://doi.org/10.1210/jc.2003-032047Park JJ, Berggren JR, Hulver MW, et al. GRB14, GPD1, and GDF8 as potential network collaborators in weight loss-induced improvements in insulin action in human skeletal muscle. Physiol Genomics. 2006;27(2):114-121. doi: https://doi.org/10.1152/physiolgenomics.00045.2006Park JJ, Berggren JR, Hulver MW, et al. GRB14, GPD1, and GDF8 as potential network collaborators in weight loss-induced improvements in insulin action in human skeletal muscle. Physiol Genomics. 2006;27(2):114-121. doi: https://doi.org/10.1152/physiolgenomics.00045.2006Amor M, Itariu BK, Moreno-Viedma V, et al. Serum myostatin is upregulated in obesity and correlates with insulin resistance in humans. Exp Clin Endocrinol Diabetes. 2019;127(8):550-556. doi: https://doi.org/10.1055/a-0641-5546Amor M, Itariu BK, Moreno-Viedma V, et al. Serum myostatin is upregulated in obesity and correlates with insulin resistance in humans. Exp Clin Endocrinol Diabetes. 2019;127(8):550-556. doi: https://doi.org/10.1055/a-0641-5546Wang F, Liao Y, Li X, Ren C, Cheng C, Ren Y. Increased circulating myostatin in patients with type 2 diabetes mellitus. J Huazhong Univ Sci Technolog Med Sci. 2012;32(4):534-539. doi: https://doi.org/10.1007/s11596-012-0092-9Wang F, Liao Y, Li X, Ren C, Cheng C, Ren Y. Increased circulating myostatin in patients with type 2 diabetes mellitus. J Huazhong Univ Sci Technolog Med Sci. 2012;32(4):534-539. doi: https://doi.org/10.1007/s11596-012-0092-9Efthymiadou A, Vasilakis IA, Giannakopoulos A, Chrysis D. Myostatin serum levels in children with type 1 diabetes mellitus. Hormones (Athens). 2021;20(4):777-782. doi: https://doi.org/10.1007/s42000-021-00317-yEfthymiadou A, Vasilakis IA, Giannakopoulos A, Chrysis D. Myostatin serum levels in children with type 1 diabetes mellitus. Hormones (Athens). 2021;20(4):777-782. doi: https://doi.org/10.1007/s42000-021-00317-yBaumgartner M, Lischka J, Schanzer A, et al. Plasma myostatin increases with age in male youth and negatively correlates with vitamin d in severe pediatric obesity. Nutrients. 2022;14(10):2133. doi: https://doi.org/10.3390/nu14102133Baumgartner M, Lischka J, Schanzer A, et al. Plasma myostatin increases with age in male youth and negatively correlates with vitamin d in severe pediatric obesity. Nutrients. 2022;14(10):2133. doi: https://doi.org/10.3390/nu14102133Ambroszkiewicz J, Chełchowska M, Mazur J, et al. Relationships between body weight status and serum levels of adipokine, myokine and bone metabolism parameters in healthy normal weight and thin children. J Clin Med. 2022;11(14):4013. doi: https://doi.org/10.3390/jcm11144013Ambroszkiewicz J, Chełchowska M, Mazur J, et al. Relationships between body weight status and serum levels of adipokine, myokine and bone metabolism parameters in healthy normal weight and thin children. J Clin Med. 2022;11(14):4013. doi: https://doi.org/10.3390/jcm11144013Bolton K, Segal D, McMillan J, et al. Decorin is a secreted protein associated with obesity and type 2 diabetes. Int J Obes (Lond). 2008;32(7):1113-1121. doi: https://doi.org/10.1038/ijo.2008.41Bolton K, Segal D, McMillan J, et al. Decorin is a secreted protein associated with obesity and type 2 diabetes. Int J Obes (Lond). 2008;32(7):1113-1121. doi: https://doi.org/10.1038/ijo.2008.41Palacios-González B, Vadillo-Ortega F, Polo-Oteyza E, et al. Irisin levels before and after physical activity among school-age children with different BMI: a direct relation with leptin. Obesity (Silver Spring). 2015;23(4):729-732. doi: https://doi.org/10.1002/oby.21029Palacios-González B, Vadillo-Ortega F, Polo-Oteyza E, et al. Irisin levels before and after physical activity among school-age children with different BMI: a direct relation with leptin. Obesity (Silver Spring). 2015;23(4):729-732. doi: https://doi.org/10.1002/oby.21029Çatlı G, Küme T, Tuhan HÜ, et al. Relation of serum irisin level with metabolic and antropometric parameters in obese children. J Diabetes Complications. 2016;30(8):1560-1565. doi: https://doi.org/10.1016/j.jdiacomp.2016.07.019Çatlı G, Küme T, Tuhan HÜ, et al. Relation of serum irisin level with metabolic and antropometric parameters in obese children. J Diabetes Complications. 2016;30(8):1560-1565. doi: https://doi.org/10.1016/j.jdiacomp.2016.07.019Blüher S, Panagiotou G, Petroff D, et al. Effects of a 1-year exercise and lifestyle intervention on irisin, adipokines, and inflammatory markers in obese children. Obesity (Silver Spring). 2014;22(7):1701-1708. doi: https://doi.org/10.1002/oby.20739Blüher S, Panagiotou G, Petroff D, et al. Effects of a 1-year exercise and lifestyle intervention on irisin, adipokines, and inflammatory markers in obese children. Obesity (Silver Spring). 2014;22(7):1701-1708. doi: https://doi.org/10.1002/oby.20739Jang HB, Kim H-J, Kang JH, et al. Association of circulating irisin levels with metabolic and metabolite profiles of Korean adolescents. Metabolism. 2017;73(8):100-108. doi: https://doi.org/10.1016/j.metabol.2017.05.007Jang HB, Kim H-J, Kang JH, et al. Association of circulating irisin levels with metabolic and metabolite profiles of Korean adolescents. Metabolism. 2017;73(8):100-108. doi: https://doi.org/10.1016/j.metabol.2017.05.007Löffler D, Müller U, Scheuermann K, et al. Serum irisin levels are regulated by acute strenuous exercise. J Clin Endocrinol Metab. 2015;100(4):1289-1299. doi: https://doi.org/10.1210/jc.2014-2932Löffler D, Müller U, Scheuermann K, et al. Serum irisin levels are regulated by acute strenuous exercise. J Clin Endocrinol Metab. 2015;100(4):1289-1299. doi: https://doi.org/10.1210/jc.2014-2932Stengel A, Hofmann T, Goebel-Stengel Met al. Circulating levels of irisin in patients with anorexia nervosa and different stages of obesity – Correlation with body mass index. Peptides. 2013;39(8):125-130. doi: https://doi.org/10.1016/j.peptides.2012.11.014Stengel A, Hofmann T, Goebel-Stengel Met al. Circulating levels of irisin in patients with anorexia nervosa and different stages of obesity – Correlation with body mass index. Peptides. 2013;39(8):125-130. doi: https://doi.org/10.1016/j.peptides.2012.11.014Huh JY, Panagiotou G, Mougios V, et al. FNDC5 and irisin in humans: I. Predictors of circulating concentrations in serum and plasma and II. mRNA expression and circulating concentrations in response to weight loss and exercise. Metabolism. 2012;61(12):1725-1738. doi: https://doi.org/10.1016/j.metabol.2012.09.002Huh JY, Panagiotou G, Mougios V, et al. FNDC5 and irisin in humans: I. Predictors of circulating concentrations in serum and plasma and II. mRNA expression and circulating concentrations in response to weight loss and exercise. Metabolism. 2012;61(12):1725-1738. doi: https://doi.org/10.1016/j.metabol.2012.09.002Moreno-Navarrete JM, Ortega F, Serrano M, et al. Irisin is expressed and produced by human muscle and adipose tissue in association with obesity and insulin resistance. J Clin Endocrinol Metab. 2013;98(4):E769-778. doi: https://doi.org/10.1210/jc.2012-2749Moreno-Navarrete JM, Ortega F, Serrano M, et al. Irisin is expressed and produced by human muscle and adipose tissue in association with obesity and insulin resistance. J Clin Endocrinol Metab. 2013;98(4):E769-778. doi: https://doi.org/10.1210/jc.2012-2749

The authors declare that there are no conflicts of interest present.