Obese and overweight children have a higher risk of asthma

(Reuters Health) – An American study suggests that overweight and obese children and adolescents are more likely to develop asthma.

While obesity has long been linked to asthma in adults, research to date has provided conflicting evidence as to whether this also applies to young people, note pediatric researchers .

This study followed more than 500,000 children aged 2 to 17 years for an average of four years. Overall, about eight percent of asthma cases had been diagnosed.

Compared with children with a healthy weight, overweight children were 17% more likely to have an asthma diagnosis and obese youth, 26% more likely to have a diagnosis of asthma. Asthma, reveals the study. This was based on a diagnosis or drug prescription for asthma, but not on the results of respiratory tests.

When researchers examined the link between asthma and obesity based on so-called spirometry tests showing how easily people can breathe air through the lungs, the link was narrower. The object was badociated with an increased risk of asthma of 29% based on these more stringent diagnostic criteria, the study revealed.

The study was not a controlled experiment designed to prove whether overweight or obesity could directly cause asthma, but the results offer some of the most compelling evidence to this day suggesting the existence of a link, said the main author of the study. Dr. Jason Lang of the Duke University School of Medicine in Durham, North Carolina.

"Experts have hypothesized that abnormal lung growth badociated with obesity causes airway obstruction," Lang said via email.

Obesity can also trigger the onset of so-called cardiometabolic risk factors such as high cholesterol and an inability to use insulin, a hormone, to transform blood sugar into energy that could lead to a deficiency of the airways, added Lang.

"Several studies have shown that asthma symptoms improve a lot with weight loss, but the exact mechanism is unknown," Lang said.

According to researchers, 23 to 27% of new cases of asthma in obese children could be directly attributable to obesity.

If no child was overweight or obese, 10% of asthma cases would be avoided, they said.

One of the limitations of the study is that researchers rely on medical records maintained by clinicians and documentation of an asthma diagnosis or spirometry order is left to the doctor's discretion, note the researchers.

It is also impossible to determine from the study whether asthma can lead to obesity or whether obesity can lead to asthma.

Still, the results suggest that it would be possible to prevent the development of asthma by helping children maintain a healthy weight, said Dr. Deepa Rastogi, director of the Center for Disease Control. Pediatric asthma from the Montefiore Children's Hospital in the Bronx, New York. .

Even with asthma, children can exercise to help them achieve and maintain a healthy weight, Rastogi said via email.

"Asthmatic children can be as active as they want. We had Olympic-level asthma athletes, "said Rastogi, who wrote an editorial published with the study.

"There is no activity that children with asthma should avoid," Rastogi added. "They must be aware of their symptoms and if they badociate a particular activity with asthma, they should take their asthma medicine called albuterol 20 to 30 minutes before participating in this activity."

SOURCE: bit.ly/2TLbCYJ Pediatrics, online November 26, 2018.