Increased bronchial responsiveness linked to reduced physical activity in children
MedWire News: Increased bronchial responsiveness is associated with reduced levels of physical activity in children, researchers have found.
Levels of physical activity, which is essential for developing physical strength and dexterity and ensuring normal growth and good health, are often lower in children with diagnosed asthma than in those without the condition, explain Hans Bisgaard and colleagues from the University of Copenhagen in Denmark.
To investigate whether physical activity levels are also reduced in children with “subclinical” asthma, the team studied 253 children (127 girls), aged 5 years, who were participating in the Copenhagen Prospective Studies on Asthma in Childhood.
All the children wore accelerometers on their ankles for 4 weeks to record their physical activity levels.
The presence of intermediary asthma phenotypes was assessed using pre- and post-bronchodilator specific airway resistance tests, assessment of bronchial responsiveness to cold dry-air hyperventilation, and measurement of exhaled nitric oxide levels.
Analysis revealed that bronchial responsiveness was inversely associated with physical activity levels among the children. Indeed, each 20% increase in bronchial responsiveness was associated with an 11% relative reduction in levels of physical activity.
There were no significant associations between physical activity levels and airway resistance, exhaled nitric oxide levels or airway resistance.
The link between bronchial responsiveness and physical activity levels remained significant after accounting for presence of asthma, age, body mass index, and sensitization.
Bisgaard and team conclude in the Journal of Allergy and Clinical Immunology: “Physical activity in preschool children was reduced with increasing bronchial responsiveness.”
They add: “The reduced physical activity was subclinical and not realized by parents or doctors despite daily diary cards and close clinical follow-up.
“This observation warrants awareness of even very mild asthma symptoms in clinical practice.”
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By Mark Cowen