Poor inspiratory muscle performance significantly relates to greater anxiety in patients with COPD

Abstract

Introduction: Psychological disorders are common in COPD. The Hospital Anxiety and Depression Scale (HADS) is a screening tool for depression and anxiety symptoms in outpatient settings and commonly used in COPD. The Test of Incremental Respiratory Endurance (TIRE) evaluates inspiratory muscle performance (IMP) via maximal inspiratory pressure (MIP) and sustained maximal inspiratory pressure (SMIP). The relationship between psychological morbidity and IMP is unclear. Aim: To examine the association between IMP and HADS outcomes in patients with COPD. Methods: Twenty-three male COPD patients (GOLD stage I-IV, mean±SD age 71±5 years) completed the anxiety and depression components of the HADS and underwent standardized examination of IMP via TIRE during which MIP was measured from RV reflecting strength, while SMIP was measured from RV to TLC representing single-breath inspiratory work capacity. The best of 3-5 consistent inspiratory efforts was used for this analysis. Results: The mean±SD height, weight, % predicted FEV1 and % predicted FVC were 177.8±7.9 cm, 82.5±22.5 kg, 39±16.2% and 65.4±16.8%, respectively. The mean±SD MIP and SMIP were 76±20.9 cmH2O and 384.8±111.3 PTU, respectively. The mean±SD HADS anxiety and depression scores were 5.7±4.1 and 4.6±2.7, respectively. Both MIP (r= -.48, p=.01) and SMIP (r= -.44, p=.04) significantly and inversely correlated to the HADS anxiety scores, but were unrelated to the HADS depression scores. Conclusions: Male COPD patients with poor IMP are more likely to be anxious. Inspiratory muscle training may play a role in reducing anxiety in this population. Further examination of this relationship in males and females with COPD is warranted.