Factors associated with daily life physical activity in patients with asthma

Little is known about the consequences of asthma on daily life physical activity (DL_PA). The aim of this study was to evaluate DL_PA and determine its relationship to clinical and functional parameters in patients with asthma.

This was a single-center prospective study of DL_PA conducted between May 2015 and June 2016 in northern France. Fifty-one adult patients with asthma and 36 healthy control subjects were enrolled. Four DL_PA parameters were assessed for 5 consecutive days with a physical activity monitor: number of steps walked per day (SPD), total energy expenditure (EE, in kcal/day), EE spent in physical activity requiring ≥3 metabolic equivalents (METs), and time (min) spent in activities requiring ≥3 METs. Clinical characteristics, pulmonary function tests, 6-minute walk test, and four questionnaires (modified Medical Research Council [mMRC] for dyspnea, asthma control test [ACT], quality of life [AQLQ], and hospital anxiety and depression scale [HADS]), were evaluated. Comparisons of DL_PA parameters between the two groups were performed using an analysis of covariance adjusted for age, sex, and body mass index (BMI). Relationships between DL_PA parameters and patient characteristics were assessed in multivariable linear regression models.

Compared with patients with mild/moderate asthma, those with severe asthma had lower mean (± standard deviation) forced expiratory volume in 1 s (FEV₁) (66 ± 24 vs 94 ± 15% predicted, P < 0.001), ACT score (16.7 ± 4.5 vs 19.8 ± 4.2, P = 0.015), and AQLQ score (157 ± 40 vs 184 ± 33, P = 0.012). There were no significant differences between the two groups in SPD (6560 ± 3915 vs 8546 ± 3431; adjusted P = 0.95), EE in physical activity requiring ≥3 METs (620 ± 360 vs 660 ± 140 kcal/day; P = 0.86), time spent in activities requiring EE ≥3 (120 ± 54 vs 121 ± 32 min/day; P = 0.69), or total EE (2606 ± 570 vs 2666 ± 551 kcal/day; P = 0.80). These four DL_PA measures showed strong inter-parameter correlations in patients with asthma (r = 0.37-0.95, all P < 0.01). All four parameters were lower in the patients with asthma group than in the control group: SPD, 7651 ± 3755 vs 11704 ± 4054 (adjusted P < 0.001); EE in activities requiring ≥3 METs, 642 ± 360 vs 852 ± 374 kcal/day (adjusted P = 0.041); time spent in activities requiring ≥3 EE, 120 ± 73 vs 189 ± 85 min (adjusted P = 0.005); and total EE, 2639 ± 555 vs 2746 ± 449 kcal/day (adjusted P = 0.007). In the patients with asthma group, the number of SPD correlated with age, FEV₁, mMRC score, 6-minute walk test distance, and HADS scores, but not with BMI or ACT test score. Using multivariate analysis, the number of SPD was associated with only age, anxiety, and FEV₁, whereas total EE was associated with mMRC score and BMI.

Age, anxiety, and FEV₁ were significantly associated with the number of SPD in patients with asthma. Addressing anxiety should be further studied as way to attempt to increase physical activity in patients with asthma.