The Effects of Nedocromil Sodium and Cetirizine HCl on Exercise-induced Arterial Hypoxemia in Highly-trained Swimmers
Status:
Recruiting
Trial end date:
2021-12-31
Target enrollment:
Participant gender:
Summary
Exercise-induced arterial hypoxemia (EIAH), a reduced amount of oxygen in the arterial blood
during exercise, has been observed in otherwise healthy, highly-trained endurance athletes
during exercise at sea level. The extent of the arterial deoxygenation may be influenced by a
histamine-mediated inflammatory response at the pulmonary capillary-alveolar membrane
limiting oxygen diffusion. Moreover, while EIAH has been routinely explored in running and
cycling, swimming is understudied despite potential mechanistic avenues which may put
swimmers at further risk for EIAH. The purpose of this study is threefold: 1) to determine
whether highly-trained swimmers experience EIAH during submaximal and maximal exercise, 2) to
determine the extent to which histamine release influences oxyhemoglobin saturation during
swimming exercise, and 3) to determine whether nedocromil sodium (NS), a mast cell
stabilizer, and cetirizine HCl (CH), an H1-receptor competitive inhibitor, can improve
oxyhemoglobin saturation during submaximal and maximal swimming exercise. Twenty-six (13 men,
13 women) highly-trained swimmers will complete an intense swimming protocol to assess the
histamine response to intense exercise. A subset with the highest histamine responses will
participate in three additional sessions (placebo, NS, and CH conditions) which will include
a swimming aerobic capacity test and 5-minutes of swimming at both 70 and 85% of their
maximal oxygen uptake.