Exploring Balance Impairment and Determinants in Chronic Obstructive Pulmonary Disease: A Comparative Study with Healthy Subjects.

Background: Many pulmonary and extrapulmonary factors may impair balance in patients with chronic obstructive pulmonary disease (COPD), but the determinants of this impairment are still debated. The primary aim was to compare both balance-related and independent variables that may affect balance with healthy subjects. The secondary aim was to investigate the potential determinants of balance in patients with COPD. Methods: This comparative study recruited 23 patients with COPD and 23 age- and comorbidity-matched healthy subjects. Participants were assessed regarding demographic and clinical data, "Postural Stability Test" (PST), "Limits of Stability Test" (LOST), "Clinical Test of Sensory Integration of Balance" (CTSIB), pulmonary function, respiratory and peripheral muscle strength, functional capacity, and cognitive function. Results: There were significant differences in all outcome measures assessing balance, pulmonary function, respiratory muscle strength, peripheral muscle strength, and functional capacity, but not cognitive function, in the COPD group compared to the healthy group ( p < 0.05). The PST had a significant and strong correlation with maximal inspiratory pressure (MIP) (r = -0.630, p = 0.001) and a significant and moderate correlation with m. quadriceps strength and 6 min walk test (6MWT) distance (r = -0.472, p = 0.023; r = -0.496, p = 0.016; respectively). MIP, m. quadriceps strength, and 6MWT distance were independent predictors to explain the PST with an R 2 = 0.336 ( p = 0.004). Conclusions: The present study revealed that balance is impaired in adults with COPD, even if compared with age- and comorbidity-matched healthy subjects. Assessing and improving balance and its determinants, inspiratory and peripheral muscle strength, and functional capacity may be important for fall prevention and disease management in patients with COPD.