Adults with severe asthma may safely perform 6-min walk test

The 6-min walk test (6MWT) appears to be safe for adult patients with severe asthma provided that they receive a bronchodilator medication prior to the test and stop once the blood oxygen saturation (SpO2) levels drop below 85 percent, according to a study.

A total of 403 adults participated in the study. Of these, 175 had severe asthma (median age 60 years, 65 percent female, median BMI 31 kg/m²), 64 had nonsevere asthma (median age 60 years, 78 percent female, median BMI 30 kg/m²), 99 had chronic obstructive pulmonary disease (COPD) (median age 71 years, 40 percent female, median BMI 30 kg/m²), and 65 were healthy controls (median age 56 years, 54 percent female, median BMI 25 kg/m²).

All participants underwent a cross-sectional multidimensional assessment that included a 6MWT. Adverse events, limiting factors, and physiological responses during the 6MWT were compared across the groups.

No adverse events occurred during the 6MWT in the severe asthma group, regardless of whether the participants were on monoclonal antibody (mAb) therapy. The percentage of participants who rested during 6MWT in the severe and nonsevere asthma groups was lower than that in the COPD group (10 percent, 9 percent, and 23 percent, respectively).

Breathlessness from the 6MWT occurred more frequently in the severe asthma group than in the nonsevere asthma and control groups (p<0.001). Fewer participants in the severe asthma vs the COPD group saw their SpO2 levels drop below 85 percent during the test (3 percent vs 14 percent; p<0.05).

The 6MWT distance did not significantly differ between mAb-treated and nontreated participants in the severe asthma group (p=0.13). Of note, participants on mAb therapy did not report any respiratory limitations during the test.