Patients with COPD with higher levels of anxiety are more physically active.
BACKGROUND
Physical activity (PA) has been found to be an excellent predictor of mortality beyond traditional measures in COPD. We aimed to determine the association between depression and anxiety with accelerometry-based PA in patients with COPD.


METHODS
We performed a cross-sectional analysis of baseline data from 148 stable patients with COPD enrolled in an ongoing, longitudinal, observational study. We measured PA (total daily step count) with a Stepwatch Activity Monitor over 7 days, depression and anxiety with the Hospital Anxiety and Depression Scales (HADSs), dyspnea with the Shortness of Breath Questionnaire, and functional capacity with the 6-min walk test.


RESULTS
Increased anxiety was associated with higher levels of PA such that for every one-point increase in the HADS-Anxiety score there was a corresponding increase of 288 step counts per day (β=288 steps, P<.001), after adjusting for all other variables. Higher levels of depressive symptoms were associated with lower PA (β=-176 steps, P=.02) only when anxiety was in the model. The interaction term for anxiety and depression approached significance (β=26, P=.10), suggesting that higher levels of anxiety mitigate the negative effects of depression on PA.


CONCLUSIONS
The increased PA associated with anxiety in COPD is, to our knowledge, a novel finding. However, it is unclear whether anxious patients with COPD are more restless, and use increased psychomotor activity as a coping mechanism, or whether those with COPD who push themselves to be more physically active experience more anxiety symptoms. Future studies should evaluate for anxiety and PA to better inform how to improve clinical outcomes.


BACKGROUND
Clinicaltrials.gov; No.: NCT01074515; URL: www.clinicaltrials.gov.
Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA. Electronic address: huong.q2.nguyen@kp.org.
Huong Q
HQ
Nguyen
University of Washington & Puget Sound Veterans Administration, Seattle, WA.
Vincent S
VS
Fan
University of Washington, Seattle, WA.
Jerald
J
Herting
University of Washington, Seattle, WA.
Jungeun
J
Lee
University of Washington, Seattle, WA.
Musetta
M
Fu
University of Washington, Seattle, WA.
Zijing
Z
Chen
University of Washington, Seattle, WA.
Soo
S
Borson
University of Washington, Seattle, WA.
Ruth
R
Kohen
University of Washington, Seattle, WA.
Gustavo
G
Matute-Bello
University of Washington, Seattle, WA.
Genevieve
G
Pagalilauan
University of Texas Health Science Center at San Antonio and The South Texas Veterans Health Care System, San Antonio, TX.
Sandra G
SG
Adams
D000368:Aged; D001007:Anxiety / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000523:psychology*; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology