Postural balance in COPD with obstructive sleep apnea: a cross-sectional study

Background: Individuals with chronic obstructive pulmonary disease (COPD) present postural balance and sleep disorders; however, their association is poorly understood. Aim: Evaluate the postural balance in individuals with COPD and with obstructive sleep apnea (OSA). Methods: The study involved individuals with moderate to very severe COPD assessed on two hospital visits. On day 1, the questionnaires Pittsburg Sleep Quality Index (PQSI) and Epworth Sleepiness Scale were applied. Then, they performed the polysomnography exam and were classified as with moderate to severe OSA (msOSA) or without (wOAS). One week later, the postural balance was evaluated through a clinical test (Mini BESTest) and a platform force. The center of pressure (CoP) was quantified with and without foam. The between-group was compared using Student9s-T or Mann-Whitney test. Results: Forty-three COPDs were evaluated (wOAS, n=27 vs. msOAS, n=16). msOAS group was older, but had a greater FEV1 than wOAS (71.3±6.8 vs. 64.6±7.4 years and 54.3±17.7 vs. 43.2±14.3% of predicted; p<0.05, respectively). msOAS showed a 30% increase in total CoP displacement than the wOAS group without foam (32.4±13 vs. 41.8±15.6cm; p<0.05). The CoP of msOAS group presented an increase in the anteroposterior direction on foam than the wOAS group (2.7±1.1 vs. 3.3±0.8cm; p<0.05, respectively). No differences were observed in the questionnaires PQSI and Epworth and mini BESTest clinical test (p>0.05). Conclusion: Our preliminary data suggest that individuals with COPD with moderate and severe OSA present a greater postural oscillation. These results suggest that sleep disorders have worse postural balance in subjects with moderate to very severe COPD.