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Mancera E1, Ramos D1, Cristancho E1, Schmidt W2, Sandra Milena C3
1Universidad Nacional de Colombia, Movimiento Corporal Humano, Bogota, Colombia, 2University of Bayreuth, Sports and Sciences, Bayreuth, Germany, 3Laboratorio de Control al Dopaje - COLDEPORTES, Bogota, Colombia
Background: The total hemoglobin mass (tHb) expresses the amount in grams of hemoglobin that is found in the body and, unlike the hemoglobin concentration, [Hb] is independent of the fluctuations in body fluids. Likewise, it is a determining factor of oxygen transport capacity and, therefore, of maximum oxygen uptake (VO2max). In children and adolescents, tHb may be influenced by biological maturation, endurance training and chronic exposure to hypobaric hypoxia (HH), which has not been described yet.
Purpose: the aim of this study was to analyze the effects of HH, biological maturation, sex and training on tHb, blood volume (BV), erythrocyte volume (EV) and plasma volume (PV) in children and adolescents.
Methods: Transversal study. Participants were 476 children and adolescents of both sexes (217 women, 259 men), Tanner IV on the sexual maturation scale, trained in endurance sports (T) and untrained controls (UT), residents at two different altitudes: low altitude (LA; 1000 m) and moderate altitude (MA; 2500 -3000 m). THb, BV, EV and PV were determined by the optimized CO rebreathing method. Hemoglobin [Hb], hematocrit (Hct), ferritin, erythropoietin (EPO) and body composition parameters were measured.
Results: Statistical analysis was carried out through linear regressions and classification and regression trees (CART). Men had higher values of tHb, BV, EV, PV and ferritin than women (p 0.001). In men, tHb, EV, BV and ferritin were mainly influenced by biological maturation and Tanner III-V subjects presented the highest values (p 0.001). Sex was the variable with the most important effect on Hbt (54%) followed by biological maturation (29.2%). The importance of the effect of altitude and training on tHb and EV was reduced (5-15%). Trained (T) men, Tanner III - V, and MA residents had the highest tHb value relative to body mass (tHb/kg) of the whole population (14.3 ± 1.2 g/kg), with a significant difference of 4.5 g/kg (p 0.0001) with respect to the group with lower tHb/kg corresponding to UT women. The PV was determined mainly by the training with higher values in the T subjects (p 0.001). A maturation and training effect was observed in the BV.
Conclusion(s): In children and adolescents, tHb and BV parameters are mainly influenced by sex and biological maturation and, to a lesser extent, by training and altitude. From puberty, tHb, EV and BV begin to increase significantly in men while in women they stabilize. There is a stimulating effect of training on tHb and BV in women and Tanner III-V men, as well as a synergistic effect of training and HH. Men Tanner III and MA are those with higher tHb/kg.
Different studies support our hypothesis that in men, tHb is affected by the production of androgens and that the increase in its production after puberty could determine the increase in tHb/kg and the marked differences with women.
Implications: The measurement of tHb in children and adolescents is important to detect sports talents in endurance sports. It also allows identifying pathologies related to hemoglobin that affect the production of energy and therefore human movement.
Keywords: puberty, total hemoglobin mass, training
Funding acknowledgements: This study was funding by Universidad Nacional de Colombia
Purpose: the aim of this study was to analyze the effects of HH, biological maturation, sex and training on tHb, blood volume (BV), erythrocyte volume (EV) and plasma volume (PV) in children and adolescents.
Methods: Transversal study. Participants were 476 children and adolescents of both sexes (217 women, 259 men), Tanner IV on the sexual maturation scale, trained in endurance sports (T) and untrained controls (UT), residents at two different altitudes: low altitude (LA; 1000 m) and moderate altitude (MA; 2500 -3000 m). THb, BV, EV and PV were determined by the optimized CO rebreathing method. Hemoglobin [Hb], hematocrit (Hct), ferritin, erythropoietin (EPO) and body composition parameters were measured.
Results: Statistical analysis was carried out through linear regressions and classification and regression trees (CART). Men had higher values of tHb, BV, EV, PV and ferritin than women (p 0.001). In men, tHb, EV, BV and ferritin were mainly influenced by biological maturation and Tanner III-V subjects presented the highest values (p 0.001). Sex was the variable with the most important effect on Hbt (54%) followed by biological maturation (29.2%). The importance of the effect of altitude and training on tHb and EV was reduced (5-15%). Trained (T) men, Tanner III - V, and MA residents had the highest tHb value relative to body mass (tHb/kg) of the whole population (14.3 ± 1.2 g/kg), with a significant difference of 4.5 g/kg (p 0.0001) with respect to the group with lower tHb/kg corresponding to UT women. The PV was determined mainly by the training with higher values in the T subjects (p 0.001). A maturation and training effect was observed in the BV.
Conclusion(s): In children and adolescents, tHb and BV parameters are mainly influenced by sex and biological maturation and, to a lesser extent, by training and altitude. From puberty, tHb, EV and BV begin to increase significantly in men while in women they stabilize. There is a stimulating effect of training on tHb and BV in women and Tanner III-V men, as well as a synergistic effect of training and HH. Men Tanner III and MA are those with higher tHb/kg.
Different studies support our hypothesis that in men, tHb is affected by the production of androgens and that the increase in its production after puberty could determine the increase in tHb/kg and the marked differences with women.
Implications: The measurement of tHb in children and adolescents is important to detect sports talents in endurance sports. It also allows identifying pathologies related to hemoglobin that affect the production of energy and therefore human movement.
Keywords: puberty, total hemoglobin mass, training
Funding acknowledgements: This study was funding by Universidad Nacional de Colombia
Topic: Sport & sports injuries; Paediatrics
Ethics approval required: Yes
Institution: Univerdiad Nacional de Colombia
Ethics committee: Ethical Comitte of Science Faculty
Ethics number: Register 06-15
All authors, affiliations and abstracts have been published as submitted.
