Transient Reduction of FMD-Response and L-Arginine Accompanied by Increased Levels of E-Selectin, VCAM, and ICAM after Prolonged Strenuous Exercise

• Published in: Sports (Basel) 2021-06, Vol.9 (6), p.86
• Main Authors: Nyborg, Christoffer, Melsom, Helene Støle, Bonnevie-Svendsen, Martin, Melau, Jørgen, Seljeflot, Ingebjørg, Hisdal, Jonny
• Format: Article
• Language: English
• Subjects: Arginine; Bioavailability; Biomarkers; Competition; E-selectin; Endothelium; Exercise; FMD; Inflammation; Intercellular adhesion molecule 1; ironman; Marathons; Physical fitness; Triathlon; Vascular cell adhesion molecule 1; Veins & arteries
• ISSN: 2075-4663; 2075-4663
• DOI: 10.3390/sports9060086

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.