Intense exercise may cause asthma-like symptoms in children
MedWire News: Intense exercise can cause asthma-like symptoms in children, even in those without a history of the respiratory condition, researchers have found.
“In adults, it is known that wheezing and decrements in pulmonary function testing can occur with vigorous exercise even in those with no prior history of asthma,” said lead researcher Alladdin Abosaida (University of California, Irvine, USA).
However, he added: “The extent of exercise associated pulmonary function testing abnormality in healthy children is relatively unstudied.”
To address this, Abosaida and team enrolled 56 healthy children (28 male) without a clinical history of asthma or atopy who were aged an average of 14.7 years.
The participants were assigned to complete two exercise tests on separate days; a constant work rate exercise test commonly used as a provocation for exercise-induced asthma, and a progressive exercise test typically used to determine maximal oxygen consumption or aerobic capacity.
All the participants underwent lung function assessments before and after completing the exercise tests. Abnormal results after exercise were defined as a decrease in FEV1 of at least 10%, a decrease of more than 26% in forced expiratory flow at 25-75% of forced vital capacity, or a decrease of more than 15% in peak expiratory flow rate.
The researchers found that 25 (45%) children had at least one abnormal lung function test result – eight (14%) after the constant work rate test and 11 (20%) after the progressive exercise test. Six (11%) children had at least one abnormal result after both tests.
There was no significant difference in the number of abnormal lung function test results between the two exercise protocols.
“We did not expect to see pulmonary function abnormalities after short periods of heavy exercise in such a large number of healthy children in our subject population,” said Abosaida.
“We speculate that either the inflammatory response to exercise or cellular changes that may occur as the result of dehydration of the airway surface, or both, led to mild airway obstruction.”
He added: “Exercise-induced asthma may represent an augmented inflammatory or allergic element to a naturally occurring phenomenon.”
The research was presented at the American Thoracic Society International Conference in New Orleans, Louisiana, USA.
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By Mark Cowen