Abstract
Background: Depression is a very common comorbidity in COPD and the consequences of untreated depression have significant impact on patients and on the course of the disease. Our aim is to estimate the association of nocturnal hypoxemia and depression in out-patient COPD subjects.
Methods: A case–control study was performed in 60 out-patient COPD subjects with clinical suspicion of nocturnal hypoxemia due to saturation levels between 90% and 94%. Thirty patients with diagnosis of major depression (cases) were evaluated and compared with thirty COPD patients without depression (controls). All patients were submitted to clinical, psychiatric evaluation, spirometry, polysomnography, transthoracic echocardiography, arterial blood gas analysis and chest radiograph.
Results: The proportion of subjects with nocturnal hypoxemia and with significant nocturnal hypoxemia was similar among cases and controls: 16 (53.3%) versus 17 (56.7%), and 5 (16.7%) versus 7 (23.3%), respectively. Nocturnal hypoxemia and significant nocturnal hypoxemia were not associated with major depression: odds ratio 1.14; 95% confidence interval, 0.41 - 3.17; p=0.80, and odds ratio 1.52; 95% confidence interval, 0.42 - 5.47; p=0.52, respectively. The ability of the COPD Assessment Test to predict major depression was similar to the Beck Depression Inventory: odds ratio 1.17; 95% confidence interval, 1.06 - 1.30; p=0.002, and odds ratio 1.24; 95% confidence interval, 1.11 - 1.39; p=0.0001, respectively.
Conclusions: Nocturnal hypoxemia was not associated with major depression. The COPD Assessment Test scores were significantly associated with the presence of major depression.
- © 2014 ERS