BMI, symptoms linked to 6-min walk distance in severe asthma

In adults with severe asthma, disease symptoms and body mass index (BMI) are both associated with exercise capacity, reports a recent study.

“Optimizing these factors may enhance the ability of patients to improve their exercise capacity and gain the associated positive health outcomes, but further studies are warranted,” the investigators said.

In this cross-sectional study, the investigators examined the association of selected clinical and biological factors with 6-min walk distance (6MWD) in adults with severe asthma and investigate the impact of sex on these outcomes.

A total of 137 adults with severe asthma (median age 59 years, 85 females) were included in the analysis. The investigators measured exercise capacity using the 6-minute walk test. They also examined the association between 6MWD and predictors using multiple linear regression.

Overall, BMI (‒3.1 m, 95 percent confidence interval [CI], ‒5.1 to ‒1.3; p=0.001) and asthma control (‒15.2 m, 95 percent CI, ‒22.6 to ‒7.7; p=0.0001) significantly correlated with exercise capacity (adjusted variance, 0.425).

In females, BMI (p<0.001) and the 5-Item Asthma Control Questionnaire (ACQ-5; p=0.005) significantly correlated with 6MWD (adjusted variance, 0.423). In males, a 0.5-point increase in ACQ-5 was associated with a 10.2-m reduction in 6MWD (95 percent CI, ‒22.8 to 2.4; p=0.11), but neither clinical nor biological factors achieved statistical significance (adjusted variance, 0.393).

“Exercise capacity is associated with health-related quality of life and symptom control in severe asthma,” the investigators said. “Thus, interventions targeting exercise capacity are likely to be beneficial.”