STRESS, ANXIETY, AND HEART RATE VARIABILITY IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Elevated levels of anxiety and high prevalence of anxiety disorders have been observed among patients with Chronic Obstructive Pulmonary Disease (COPD). Decreased heart rate variability has been associated with COPD and poor emotional regulation, but there have not been any prior studies investigating decreased heart rate variability (HRV) as an underlying mechanism that may partially explain the high levels of anxiety in COPD patients. The current study utilized a 2 (disease status) X2 (anxiety group) factorial design with four groups (COPD, COPD-ANX, HEA, HEA-ANX) examining heart rate variability associated with anxiety symptoms in COPD patients compared to healthy controls when exposed to a modified Trier Social Stress Task. Participants were evaluated with pulmonary function tests, HRV monitoring, and self-report questionnaires assessing health behaviors, psychological factors, and dispositional variables. 30 COPD patients were age- and gender-matched with 30 healthy controls. Mean age was 59.1 (±11.2) years and 50% of the participants were female. Participants with COPD presented with severe airway obstruction [mean forced expiratory volume in one second / forced vital capacity ratio (FEV1/FVC) = 0.63 (± 0.15)]. There were no significant differences in resting HRV between groups.

Repeated measures ANOVA revealed that the COPD-ANX and HEA-ANX groups displayed a blunted response to a stressor. Although this study was unable to distinguish HRV differences unique to the COPD population, HRV responses to stress in anxious individuals with and without COPD were blunted. Future studies of COPD patients and healthy controls investigating HRV should measure anxiety to avoid the potential confound of high anxiety levels among patients with COPD. Results revealed that the COPD-ANX group had significantly lower psychological well-being and poorer sleep quality than the COPD group. Furthermore, individuals in the COPD-ANX group with pre-existing anxiety prior to their COPD diagnosis had lower resting vagal tone. Future studies should focus on distinguishing between individuals who have preexisting anxiety prior to their COPD diagnosis compared to individuals who developed anxiety after their COPD diagnosis.