Adults with asthma are at an increased risk for obesity that is not explained by lack of physical activity, researchers report.

The prospective cohort study of 7576 people participating in the European Community Respiratory Health Survey found the risk of developing obesity was higher among those with asthma compared to those without asthma (RR 1.22; 95% CI 1.07 to 1.38) after adjusting for potential confounders. 

The association was stronger among those without atopy (1.47; 95% CI 1.17 to 1.86), asthmatics with longer disease duration (1.32; 95% CI 1.10 to 1.59), asthmatics who used OCS (1.99; 95% CI 1.26 to 3.15) and those who used both OCS and ICS (2.07; 95% CI 1.19 to 3.59).

The risk was not mediated by physical activity, the research team reported in their paper published in Thorax. 

According to the authors, their results and those of previous trials suggest that asthma and obesity share several common physiological pathways, with a bidirectional association between asthma and obesity ‘plausible’.

Their findings were also of significant clinical importance as they advocated for “the minimal and precise use of OCS in asthma”. 

“These results support earlier results in children and warrant further clinicoepidemiological and experimental research, in order to determine the mechanisms through which asthma could trigger obesity risk among adults,” they concluded.

“Understanding the crosstalk between asthma and obesity would [also] help set a proper strategy for asthma management, particularly with an emphasis on reducing adverse effects of corticosteroids in asthma treatment,” they added.