Serum Human Epididymal Protein 4 is Associated with Depressive Symptoms in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND: Previous studies have suggested that patients with chronic obstructive pulmonary disease (COPD) have a higher incidence of depression and an increased risk of developing various depression-related complications. We aimed to elucidate the association between the serum human epididymal protein 4 (HE4) level and depressive symptoms in patients with COPD. METHODS: The data on 219 participants with COPD from The Irish Longitudinal Study on Ageing (TILDA) were analyzed for the association between serum HE4 levels and depressive symptoms, accounting for relevant confounding factors. All the COPD participants were prospectively followed up for a median period of 48 months. Cox proportional hazards analysis was used to evaluate the predictive value of serum HE4 for predicting depression events in these COPD patients. RESULTS: Multivariate linear regression analysis revealed that serum HE4 was independently associated with the depression score after adjusting for age, sex, BMI, current smoking status, current drinking status, admission systolic and diastolic BP, CVD history and laboratory measurements in patients with COPD at baseline (Sβ= 0.149; 95% CI, 0.069–0.201; P<0.001). Multivariate Cox proportional hazards analysis revealed that serum HE4 (HR=2.216, 95% CI 1.691–5.109, P<0.001) was an independent prognostic factor for depression events in these COPD patients. CONCLUSION: Our results showed that serum HE4 is significantly and independently associated with depression events. Serum HE4 may enable the early recognition of depressive symptoms among COPD patients.