Risk Factors for Depression in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND: Depression is a major comorbidity in patients with chronic obstructive pulmonary disease (COPD). The aim of this prospective study was to investigate socio-demographic and clinical factors and serum markers of inflammation, including cytokines that, may be a cause or an association with COPD-related depression. MATERIAL/METHODS: This study enrolled 53 patients who were hospitalized in the Department of Respiratory Medicine of Hefei First People’s Hospital, China between October 2015 and October 2016. Patients were consecutively recruited who were diagnosed with COPD and without lower respiratory tract disease, psychiatric disorders, or a family history of cognitive disorders. All patients were investigated for symptoms of depression. Lung function testing included forced expiratory volume in 1 second (FEV(1)). Serum levels of C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) were measured. RESULTS: Of the 53 patients with COPD, 40 (75.47%) patients had symptoms of depression. Univariate analysis showed that gender, smoking, a high level of education, duration of a cough, FEV(1), and serum CRP level were associated with depression. A multivariate logistic regression model identified two risk factors for depression in patients with COPD: serum CRP level and FEV(1). CONCLUSIONS: The findings of this study showed that the risk factors for COPD-related depression included male gender, heavy smoking, higher academic qualifications, and duration of cough, but the two strongest risk factors were a high serum CRP level and low FEV(1).