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Front. Physiol. | doi: 10.3389/fphys.2018.01368

Mountain Ultramarathon Induces Early Increases of Muscle Damage, Inflammation and Risk for Acute Renal Injury

  • 1Universidade Estadual de Campinas, Brazil

Purpose: This study aimed to investigate changes in muscle damage during the course of a 217-km mountain ultramarathon (MUM). In an integrative perspective, inflammatory response and renal function were also studied. Methods: Six male ultra-runners were tested four times: pre-race, at 84-km, at 177-km, and immediately after the race. Blood samples were analyzed for serum muscle enzymes, acute-phase protein, cortisol, and renal function biomarkers. Results: Serum creatine kinase, lactate dehydrogenase, and aspartate aminotransferase increased significantly throughout the race (P < 0.001, P< 0.001; P = 0.002, respectively), and effect size (ES) denoted a large magnitude of muscle damage. These enzymes increased from pre-race (132 ± 18, 371 ± 66, and 28 ± 3 U/L, respectively) to 84-km (30, 1.8, 3.9-fold, respectively); further increased from 84-km to 177-km (4.6, 2.9, 6.1-fold, respectively); followed by a stable phase until the finish line. Regarding the inflammatory response, significant differences were found for C-reactive protein (CRP) (P < 0.001) and cortisol (P < 0.001). CRP increased from pre-race (0.9 ± 0.3 mg/L) to 177-km (243-fold), cortisol increased from pre-race (257 ± 30mmol/L) to the 84-km (2.9-fold), and both remained augmented until the finish line. Significant changes were observed for creatinine (P = 0.03), urea (P = 0.001), and glomerular filtration rate (GFR) (P < 0.001), and ES confirmed a moderate magnitude of changes in renal function biomarkers. Creatinine and urea increased, and GFR decreased from pre-race (1.00 ± 0.03 mg/dL, 33 ± 6 mg/dL, and 89 ± 5 ml/min/1.73 m2, respectively) to 84-km (1.3, 3.5, 0.7-fold, respectively), followed by a plateau phase until the finish line. Conclusion: This study shows evidence that muscle damage biomarkers presented early peak levels and they were followed by a plateau phase during the last segment of a 217-km MUM. The acute-phase response had a similar change of muscle damage. In addition, our data showed that our volunteers meet the risk criteria for acute kidney injury from 84-km until they finished the race, without demonstrating any clinical symptomatology.

Keywords: muscle damage, Inflammation, Renal function, Dehydration, Ultramarathon

Received: 19 Jul 2018; Accepted: 10 Sep 2018.

Edited by:

Leonardo A. Peyré-Tartaruga, Universidade Federal do Rio Grande do Sul (UFRGS), Brazil

Reviewed by:

Leonardo Roever, Federal University of Uberlandia, Brazil
Katsuhiko Suzuki, Waseda University, Japan  

Copyright: © 2018 Belli, Macedo, De Araujo, Masselli Dos Reis, Scariot, Lazarim, NUnes, Brenzikofer and Gobatto. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Dr. Taisa Belli, Universidade Estadual de Campinas, Campinas, Brazil,