Circulating microRNAs after a 24-h ultramarathon run in relation to muscle damage markers in elite athletes.

Stéphanie Bourdon,Emeric Chalchat,Julien Siracusa,Keyne Charlot,Cyprien Bourrilhon,Vincent Martin,Stéphane Baugé,Julie Bompard,Pierre Hertert,Sebastian Garcia‐Vicencio,Cédric Farges

doi:10.1111/sms.14000

Abstract

Ultra-endurance sports are growing in popularity but can be associated with adverse health effects, such as exercise-induced muscle damage (EIMD), which can lead to exertional rhabdomyolysis. Circulating microRNAs (miRNAs) may be useful to approach the degree of EIMD. We aimed to (1) investigate the relevance of circulating miRNAs as biomarkers of muscle damage and (2) examine the acute response of skeletal/cardiac muscle and kidney biomarkers to a 24-h run in elite athletes. Eleven elite athletes participated in the 24-h run World Championships. Counter-movement jump (CMJ), creatine kinase (CK), myoglobin (Mb), creatinine (Cr), high-sensitive cardiac troponin T (hs-cTnT), and muscle-specific miRNA (myomiR) levels were measured before, immediately after, and 24 and 48h after the race. CMJ height was reduced immediately after the race (-84.0±25.2%, p<0.001) and remained low at 24h (-43.6±20.4%, p=0.002). We observed high CK activity (53239±63608 U/L, p<0.001) immediately after the race, and it remained elevated 24h after (p<0.01). Circulating myomiR levels (miR-1-3p, miR-133a-3p, miR-133b, miR-208a-3p, miR-208b-3p, and miR-499a-5p) were elevated immediately after the 24-h run (fold changes: 18-124,723, p<0.001) and significantly (p<0.05) correlated or tended to significantly (p<0.07) correlate with the reduction in CMJ height at 24h. We found no significant correlation between CMJ height loss at 24h and CK (p=0.23) or Mb (p=0.41) values. All elite ultramarathon runners included in our study were diagnosed with exertional rhabdomyolysis after the 24-h ultramarathon race. MyomiR levels may be useful to approach the degree of muscle damage.

Highlights

Ultra-endurance and ultramarathon events (> 42.195 km) have experienced considerable growth in recent years
We found no significant correlation between the reduction in Counter-movement jump (CMJ) height at 24 h and creatine kinase (CK) (p = 0.23) or Mb (p = 0.31) levels measured at the end of the 24-h ultramarathon (Figure 5)
We observed an increase in the level of all our target muscle-specific miRNAs immediately after the end of the exercise, which often correlated with muscle function measured 24 h after the end of the ultramarathon race

Summary

Introduction

Ultra-endurance and ultramarathon events (> 42.195 km) have experienced considerable growth in recent years. Their growing popularity, along with the constant pursuit of overcoming one’s limitations, has given rise to extremely challenging sports events. A 24-h run is a form of ultramarathon in which a competitor runs as far as possible in 24 h on a short loop (400 – 2,500 m). The current World records are 303.5 km for men and 270.1 km for women, corresponding to mean running speeds of ~12.6 and ~11.3 km/h, respectively. The extreme duration and high number of stretch-shortening cycles performed by exercising muscles over the 24-h race result in a high level of exercise-induced muscle fatigue and damage, which translates into an acute reduction in performance[3]

Objectives

Methods

Results

Conclusion