Salivary antimicrobial protein responses during multistage ultramarathon competition conducted in hot environmental conditions

Gill, Samantha, Teixeira, Ana Maria, Rama, Luis, Rosado, Fátima, Hankey, Joanne, Scheer, Volker, Robson-Ansley, Paula and Costa, Ricardo (2013) Salivary antimicrobial protein responses during multistage ultramarathon competition conducted in hot environmental conditions. Applied Physiology, Nutrition, and Metabolism, 38 (9). pp. 977-987. ISSN 1715-5312

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Prolonged strenuous exercise is commonly reported to depress oral-respiratory immune status and increase the incidence of upper respiratory symptoms. This novel investigation aimed to determine the salivary antimicrobial responses and hydration status of ultraendurance runners (n = 23) during a 230-km multistage ultramarathon conducted in hot ambient conditions (32–40 °C). Body mass was measured and unstimulated saliva and venous blood samples were taken before and after each stage of the ultramarathon. Ad libitum fluid intake was permitted throughout each race day. Upper respiratory symptoms were monitored during and until 4 weeks after race completion. Samples were analyzed for salivary immunoglobulin A (IgA), lysozyme, α-amylase, and cortisol, as well as for plasma and saliva osmolality. Mean exercise-induced body mass loss over the 5 stages ranged from 1.3% to 2.4%. Overall mean pre- and post-stage plasma osmolality measurements in the ultraendurance runners were 279 ± 14 mOsmol·kg−1 and 293 ± 15 mOsmol·kg−1, respectively. Decreases in saliva flow rate (overall change 22%) and post-stage increases in saliva osmolality (36%) were observed in the ultraendurance runners during the ultramarathon. Reduced salivary IgA (32%) (p < 0.001 vs. pre-stage salivary IgA), enhanced salivary α-amylase (187%) (p < 0.001 vs. pre-stage salivary α-amylase), and no change in salivary lysozyme secretion rates were observed in the ultraendurance runners throughout the ultramarathon. Only 1 ultraendurance runner reported upper respiratory symptoms during and 1 month after competition. Observed depressions in salivary IgA secretion rates were offset by favourable increases in salivary α-amylase and unchanged lysozyme responses in the majority of runners during the competition. Ensuring euhydration throughout a multistage ultramarathon competition in the heat may play a role in protecting the upper respiratory tract.

Item Type: Article
Uncontrolled Keywords: immunoglobulin A, α-amylase, lysozyme, upper respiratory, running, water
Subjects: B900 Others in Subjects allied to Medicine
Department: Faculties > Health and Life Sciences > Sport, Exercise and Rehabilitation
Depositing User: Users 6424 not found.
Date Deposited: 15 Oct 2013 12:54
Last Modified: 12 Oct 2019 16:25

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