Anxiety and depression impact exertional breathlessness in daily life and during exercise testing: the CanCOLD study

Exertional breathlessness is a limiting symptom that often coexists with anxiety and depression. We tested the hypothesis that anxiety and depression negatively impact exertional breathlessness in daily life and during standardised cardiopulmonary exercise testing (CPET).

Analysis of people aged ≥40 years undergoing incremental cycle CPET. Exertional breathlessness in daily life was assessed using the Modified Medical Research Council (mMRC) scale and CPET normative reference equations. CPET abnormal exertional breathlessness was defined as a breathlessness (Borg 0-10) intensity rating above the upper limit of normal at peak exercise. Associations of anxiety and depression (Hospital Anxiety and Depression Scale (HADS)) with exertional breathlessness were analysed using multivariable regression models adjusting for anthropometrics, smoking, comorbidities, and lung function at rest and during CPET.

Across 1155 participants (42% women; 66±10 years), 12% had anxiety and 6% had depression (HADS≥8), 5% experienced exertional breathlessness in daily life (mMRC≥2), and 22% and 16% showed abnormal breathlessness on CPET by power output (W) and minute ventilation (V'_E). Worse anxiety and depression scores were independently associated with perceiving worse breathlessness in daily life (anxiety: OR 1.08, 95% CI 0.98-1.19; depression: OR 1.18, 95% CI 1.06-1.31) and with more abnormal breathlessness on CPET in relation to W and V'_E (p<0.001 for all analyses).

This is the first study to show that the association of anxiety and depression with worse breathlessness in daily life persists during standardised CPET, independent of a wide range of disease severity markers - making these psychological symptoms important therapeutical targets.