Movement behaviours are associated with lung function in middle-aged and older adults: A cross-sectional analysis of the Canadian longitudinal study on aging

Background: Physical activity has been shown to attenuate the age-associated decline in lung function; however, there is little research evaluating different movement behaviours as potential correlates of lung function. Modifiable determinants need to be identified, as the prevalence of chronic respiratory disease is on the rise. The purpose of this study was to investigate associations of self-reported movement behaviours (i.e., sitting time, walking, different intensities of physical activity, and strengthening activities), with lung function in middle-aged and older adults without a respiratory disease, according to their smoking history. Methods: Data from participants of the Canadian Longitudinal Study on Aging were used for analysis (n = 16,839). Lung function was assessed using spirometry. A modified version of the Physical Activity Scale for the Elderly was used to assess sitting time and physical activity levels. Smoking status was classified as non-smoking, < 10 pack years smoking, and 10 or more pack years of smoking. The association between movement behaviours and lung function was assessed using hierarchical linear regression models with all covariates (age, sex, smoking status, body mass index, education, retirement status, and sleep duration) entered into block 1, and all movement behaviours entered into block 2. Results: All movement behaviours were associated with Forced Expiratory Volume in 1 s (FEV₁) and Forced Vital Capacity (FVC) % predicted in crude and adjusted models, regardless of smoking status. Sitting time was negatively associated with both FEV_1%pred (β: -0.094, CI: -0.140, - 0.047) and FVC_%pred (β: -0.087, CI: -0.128, -0.045) among those who never smoked, and strength activity was positively associated with both FEV_1%pred (β: 0.272, CI: 0.048, 0.496) and FVC_%pred (β: 0.253, CI: 0.063,0.442) among those who smoked < 10 pack years, as well as with FVC_%pred among those who smoked 10 or more pack years (β: 0.309, CI: 0.064, 0.554). Conclusions: This is the first study to assess the association of different movement behaviours with lung function among middle-aged and older adults without a respiratory disease. These findings indicate that movement behaviours are correlates of lung function, and that they may be modifiable determinants of the age-associated decline in lung function.