Anxiety and depression in patients with chronic obstructive pulmonary disease and their relation to serum vitamin D levels

Abstract

Objectives: To determine whether serum vitamin D levels were related to the risk of anxiety and depression among patients with chronic obstructive pulmonary disease (COPD), as well as their spirometry parameters, disease severity, and other clinical findings. Materials and Methods: Ninety-two stable patients with COPD aged over 18 years with no exacerbations in the previous month were included. Symptom severity was assessed using the modified Medical Research Council (mMRC) dyspnea scale and COPD Assessment Test (CAT) scores. Spirometry tests were performed and previous hospitalization histories were recorded to determine ABCD groups of the patients according to their combined COPD assessments. Their Body mass index, airflow Obstruction, Dyspnea and Exercise capacity (BODE) indices were calculated and the Hospital Anxiety and Depression Scale (HADS) was administered. Serum vitamin D levels were determined using immune electrochemiluminescence. Results: According to the HADS scores, 16 patients (17.4%) had the risk of anxiety and 29 (31.5%) had the risk of depression. The risk of anxiety differed significantly (P=0.016 Fischer's exact test) between the ABCD groups. Anxiety scores were positively correlated with both mMRC (r=0.315; P=0.002) and CAT (r=0.445; P=0.000) scores. Similarly, depression scores correlated positively with mMRC (r= 0.249; P=0.017) and CAT (r=0.373; P=0.000) scores. Neither anxiety nor depression scores were significantly correlated with % of predicted FEV1. Serum vitamin D levels were inversely correlated with anxiety (r=-0.215; P=0.039) and depression (r=-0.244; P=0.019) scores. Anxiety scores were positively correlated with BODE although not statistically significantly (r=0.199; P=0.058). Conclusion: A negative correlation was revealed between serum vitamin D levels and HADS scores, and symptom scores were positively correlated to HADS scores, independent of % of predicted FEV1.