Increased asthma severity correlates with less physical activity, more TV time in children

Study data showed that preschool-aged children with asthma spent significantly more time watching TV than their healthy peers and that poor asthma control was linked with less frequent physical activity.

In the study, published in Allergy, the researchers wrote that exercise-induced asthma (EIA) affects approximately 70% to 90% of children with asthma. Also, specific recommendations on physical activity for children with asthma are lacking.

“Physical activity is beneficial both for growth and the psychological development of children,” the researchers wrote. “Although it is agreed that it is essential for asthmatic children to participate in sports, fear of EIA might prevent the practice of regular physical activity in children, particularly the ones with severe and/or uncontrolled asthma.”

To evaluate any differences in physical activity levels and daily TV viewing among children with and without asthma, the researchers evaluated data of 140 patients (mean age, 5.3 years; 82 boys) with mild-to-moderate asthma and 53 healthy controls (mean age, 5 years; 22 boys) from the PreDicta study.

The patient group reported higher daily TV viewing than controls, with 59% of patients with asthma watching 1 to 3 hours of TV daily vs. 42% of controls, and 47% of controls watching less than 1 hour per day vs. 26% of patients (P < .05 for both).

Children with poor asthma control were more physically inactive, with 75% taking part in no or occasional physical activity vs. 20% of those with controlled asthma (P < .0001) and 25% of controls. However, patients with good asthma control participated in more physical activity, with 62% active three or more times per week and 18% active one to two times per week.

Differences in daily TV viewing findings according to asthma control did not reach significance, with 81% of children with uncontrolled asthma watching more than 1 hour per day compared with 78% of those with partially controlled asthma and 70% of those with controlled asthma.

Researchers also sought to evaluate the influence of physical activity and TV viewing on the immune system of children with asthma by evaluating cytokine levels in response to different immune stimuli. They found that children with asthma with higher physical activity had elevated cytokine levels in response to stimulants compared with those with low physical activity and high TV viewing time, which “suggests a readiness of circulating immune cells for type 1, 2 and 17 cytokine release” or also may “represent a proinflammatory state” among children with asthma and greater physical activity, they wrote.

Although children with asthma who were never or only occasional physically active and those who watched TV for 3 or more hours per day had high correlations of proinflammatory cytokines, the researchers found few such correlations in the healthy controls with the same average physical activity or TV time.

Limitations included the lack of objective criteria for diagnosing asthma in preschool-aged children and the subjective reports of physical activity and TV attendance from parents.

“Our work shows an association of limited physical activity with poor asthma control and that both physical activity and [TV attendance] possibly impact systemic immune response and immune and inflammatory thresholds in asthmatic preschoolers,” the researchers wrote.

“It is of great importance not to forget about the association of physical inactivity, poor physical cardiovascular fitness and obesity — all of which threatens a child's health and well-being,” they concluded.