Accelerated Red Blood Cell Turnover Following Extreme Mountain Ultramarathon?

Autor:	Krumm B, Raberin A; Institute of Sport Sciences, University of Lausanne, SWITZERLAND., Citherlet T; Institute of Sport Sciences, University of Lausanne, SWITZERLAND., Tagliapietra G; Institute of Sport Sciences, University of Lausanne, SWITZERLAND., Faiss R, Pialoux V; Inter-University Laboratory of Human Movement Biology EA7424, University Claude Bernard Lyon 1, FRANCE., Debevec T, Giardini G; Mountain Medicine and Neurology Centre, Valle D'Aosta Regional Hospital, Aosta, ITALY., Millet GP; Institute of Sport Sciences, University of Lausanne, SWITZERLAND.
Jazyk:	angličtina
Zdroj:	Medicine and science in sports and exercise [Med Sci Sports Exerc] 2024 Dec 04. Date of Electronic Publication: 2024 Dec 04.
DOI:	10.1249/MSS.0000000000003621
Abstrakt:	Introduction: Mountain ultramarathon induces extreme physiological stress for the human body. For instance, a decrease in total hemoglobin mass (Hbmass) due to severe hemolysis is historically suspected. Nevertheless, hematological changes following a 330-km mountain ultramarathon have to date never been investigated. Methods: Blood volumes were determined before (pre-) and after (post-) a 330-km race completed by thirteen participants, through the automated carbon monoxide (CO)-rebreathing method. Native and normalized blood viscosity were determined using a cone/plate viscometer at five different speeds (11.25 to 225 s-1). Biomarkers of inflammation, erythropoiesis, and hemolysis were additionally quantified. Results: Following the race, an 18% rise in PV (3338 ± 568 vs. 3928 ± 590 mL; p = 0.001) was observed, while absolute Hbmass (802 ± 102 vs. 833 ± 111 g; p = 0.09) did not change significantly. A decrease in native viscosity was reported at all speeds (p < 0.001) with a significant reduction for normalized viscosity at low to intermediate speeds only (i.e. 11.25, 22.5, and 45 s-1). Marked inflammation was suggested by upregulated interleukin-6 (7.1 ± 8 vs. 16.5 ± 14 ng⋅L-1, p = 0.011) and C-reactive protein levels (12.3 ± 14 vs. 51.6 ± 14 μg⋅mL-1, p = 0.001). Besides, the increased erythropoietin (5.7 ± 3 vs. 12 ± 6 mU⋅mL-1, p = 0.021) and erythroferrone levels (6.5 ± 4 vs. 8.5 ± 4 ng⋅L-1, p = 0.001) may indicate enhanced erythropoiesis. Conclusions: Overall, these findings suggest an enhanced red blood cell turnover, probably triggered by limited exercise-induced hemolysis (although still supported by the decrease in corrected viscosity), likely balanced through accelerated erythropoiesis. Competing Interests: Conflict of Interest and Funding Source: This research was supported by the University of Lausanne as part of its internal funding mechanisms. The authors have no conflicts of interest to declare. (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)
Databáze:	MEDLINE
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