The role of physical inactivity in increasing disability among older adults with obstructive airway disease.

Purpose: : The independent contribution of physical inactivity to disability in obstructive lung disease (OLD) is difficult to study, partly because inactivity may reflect disease severity. We examined the relationship of physical inactivity to disability progression over a 1-year period among a group of older adults with OLD.
Methods: : A population-based cohort with self-reported physician-diagnosed emphysema, chronic obstructive pulmonary disease, or chronic bronchitis (n = 206) completed baseline interviews and in-person spirometry, with 1-year followup interviews. The Community Health Activities Model Program for Seniors physical activity questionnaire provided estimates of energy expenditure; we defined inactivity as no expenditure in moderate- or vigorous-intensity activities. Disability was measured with the Valued Life Activity (VLA) disability scale; increased disability was defined as a 10% or greater increase in VLA disability score over 1-year followup. Logistic regression tested the relationship between baseline inactivity and disability increase, controlling for age, sex, baseline VLA disability, comorbidities, smoking, and pulmonary function (forced expiratory volume in 1 second, % predicted).
Results: : Of 206 subjects, 48 (27%) were physically inactive at baseline; 42.9% of individuals whose disability increased were inactive at baseline compared with 23.4% of those who did not experience a disability increase. With adjustment for covariates, increased disability after 1 year was significantly (P = .04) more likely among individuals who were inactive at baseline (Odds Ratio =2.4; 95% confidence interval, 1.02-5.9).
Conclusions: : Physically inactive individuals with OLD had more than double the odds of an increase in disability, even after controlling for baseline disability, lung function, and other covariates. These results provide strong support for the importance of maintaining physical activity among individuals with OLD.