Incidence of exercise-associated hyponatremia during a high-altitude 161-km ultramarathon.

Content Provider	Europe PMC
Author	Khodaee, Morteza Saeedi, Anahita Harris-Spinks, Christine Hew-Butler, Tamara
Copyright Year	2021
Abstract	[Purpose] Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161-km race held at a high altitude (2,800 m-3,840 m). [Methods] Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na+]) level. [Results] Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30-hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na+] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na+] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na+] levels were associated with higher serum creatine kinase values (R2=0.1, p<0.005). [Conclusion] High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC8580585&blobtype=pdf
Volume Number	25
DOI	10.20463/pan.2021.0016
PubMed Central reference number	PMC8580585
Issue Number	3
PubMed reference number	34727684
Journal	Physical Activity and Nutrition [Phys Act Nutr]
e-ISSN	27337545
Language	English
Publisher	Korean Society for Exercise Nutrition
Publisher Date	2021-09-30
Access Restriction	Open
Rights License	This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2021 Korean Society for Exercise Nutrition
Subject Keyword	ultra-endurance mountain running serum electrolytes
Content Type	Text
Resource Type	Article
Subject	Physical Therapy, Sports Therapy and Rehabilitation Physiology Health (social science) Orthopedics and Sports Medicine Nutrition and Dietetics