Asthma Appears to Increase Risk of Obesity in Adults

Subhabrata Moitra, PhD

The route between obesity and asthma might be a two-way street.

That’s the finding of a new study that looked at whether asthma might lead to obesity. The reverse—obesity increasing the risk of asthma—has already been established. Subhabrata Moitra, PhD, of the Barcelona Institute of Global Health, said the relationship was so well-established that he and colleagues wondered if the reverse might be true.

Then, last year, researchers from the University of Southern California released findings suggesting that asthma might increase the risk of obesity in children.

“That paper inspired us to take our hypothesis forward and test whether what was seen among children was also true among adults,” Moitra told MD Magazine®.

To assess the question, Moitra and colleagues used data from the European Community Respiratory Health Survey. Patients who were obese at the start of the study were excluded from Moitra’s analysis. That left 8618 patients from 12 countries in the study. Those patients, who were enrolled beginning in the 1990s, received follow-up examinations at 10 years and 20 years.

In this study, patients with asthma were defined as those who reported having asthma and who had had a serious episode—such as an asthma attack or shortness of breath that woke them up—in the past 12 months, or those who were taking a medication for asthma.

The data showed that 10.2% of patients with asthma were obese at the ten-year mark, compared to 7.7% of the non-asthmatic patients.

Risk was not spread evenly among all of patients with asthma. People who developed asthma as adults were at a higher risk of becoming obese. Another factor that increased obesity risk was having asthma without allergies. Moitra said it’s not yet known exactly why those factors increase the risk of being seriously overweight.

“It is difficult at this moment to come to any conclusion whether these are two different entities or share some common mechanisms,” he said. “We need some mechanistic research to shed light on this issue.”

The risk of obesity observed in this study was smaller than the 51% increase in risk of obesity observed in USC’s childhood study. In that case, the researchers noted that use of a rescue medication appeared to lower the risk of obesity, though the authors said it’s not known exactly why that’s the case.

What is clear is that physicians who treat patients with asthma need to be focused on the heightened potential for the patient to become obese, Moitra said.

“Weight gain among asthmatics is rarely monitored or sometimes even neglected by the physicians,” he said. “Therefore, the clinicians must be vigilant while following up their patients or at least ask some questions to a new asthma patient whether the patient gained significant weight in the last few years.”

As with any patient at risk of obesity, physicians should counsel patients with asthma about the importance of a healthy diet and regular exercise, Moitra said. He advised they also practice caution when prescribing oral corticosteroids.

The study was presented at the European Respiratory Society’s International Congress.