Obesity doesn't make asthma worse for kids

Although it's established that overweight kids are more likely to develop asthma, new research suggests that obesity has little impact on the course of the disease.

The asthma seen in obese and overweight children appears to be no more severe than that found in normal-weight kids, according to study findings presented here this week at the annual scientific meeting of the American College of Allergy, Asthma, and Immunology.

"We were amazed to see little difference in asthma outcomes between obese/overweight children and normal weight children," lead author Dr. Umit B. Emre, from Beth Israel Medical Center in New York, told Reuters Health. "Their symptoms...were more or less comparable."

This runs counter to what is seen in adults, Emre noted. "Studies have shown that obese adults with asthma tend to do worse than lean asthmatics."

The findings are based on analysis of data from 85 children and adolescents who were evaluated for asthma at a community-based practice between 1999 and 2003. In all cases, asthma was the primary diagnosis and no other major diseases were present.

Based on standard measurements, 31 subjects were classified as normal weight, 21 as overweight, and 33 as obese. Age, gender, and race distribution within the three weight groups was similar.

The majority of subjects - 53 percent- were classified as having persistent mild asthma, followed by 34 percent with intermittent asthma, and 13 percent with persistent moderate-severe asthma. The ratio of these types was also similar in the three weight groups.

The severity of asthma went hand-in-hand with the number of asthma drugs that kids needed to take and the number of visits made to the emergency room. As expected, both measures were highest for children with persistent moderate-severe asthma.

In contrast, the weight group did not influence either medication use or ER visits. The researchers also found no difference between the weight groups in lung function tests.

Emre said that the association between obesity and worse asthma outcomes "may just be a matter of time. Obesity may not be such a big deal in children with asthma, but after 20 or 30 years it may start to have an impact."

However, Emre noted that the study may have failed to show an association between asthma and obesity in children because of the types of patients selected to participate.

All of the subjects in the study were relatively "bad asthmatics," which could make it more difficult to detect any differences based on body weight. Also, it's possible that other outcomes, such as quality of life, need to be evaluated to detect a difference, she said.