Anxiety is associated with diminished exercise performance and quality of life in severe emphysema: a cross-sectional study.
BACKGROUND
Anxiety in patients with chronic obstructive pulmonary disease (COPD) is associated with self-reported disability. The purpose of this study is to determine whether there is an association between anxiety and functional measures, quality of life and dyspnea.


METHODS
Data from 1828 patients with moderate to severe emphysema enrolled in the National Emphysema Treatment Trial (NETT), collected prior to rehabilitation and randomization, were used in linear regression models to test the association between anxiety symptoms, measured by the Spielberger State Trait Anxiety Inventory (STAI) and: (a) six-minute walk distance test (6 MWD), (b) cycle ergometry peak workload, (c) St. Georges Respiratory Questionnaire (SRGQ), and (d) UCSD Shortness of Breath Questionnaire (SOBQ), after controlling for potential confounders including age, gender, FEV1 (% predicted), DLCO (% predicted), and the Beck Depression Inventory (BDI).


RESULTS
Anxiety was significantly associated with worse functional capacity [6 MWD (B = -0.944, p < .001), ergometry peak workload (B = -.087, p = .04)], quality of life (B = .172, p < .001) and shortness of breath (B = .180, p < .001). Regression coefficients show that a 10 point increase in anxiety score is associated with a mean decrease in 6 MWD of 9 meters, a 1 Watt decrease in peak exercise workload, and an increase of almost 2 points on both the SGRQ and SOBQ.


CONCLUSIONS
In clinically stable patients with moderate to severe emphysema, anxiety is associated with worse exercise performance, quality of life and shortness of breath, after accounting for the influence of demographic and physiologic factors known to affect these outcomes.


BACKGROUND
ClinicalTrials.gov NCT00000606.
Giardino
Nicholas D
ND
Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA. ngiardin@umich.edu
Curtis
Jeffrey L
JL
Andrei
Adin-Cristian
AC
Fan
Vincent S
VS
Benditt
Joshua O
JO
Lyubkin
Mark
M
Naunheim
Keith
K
Criner
Gerard
G
Make
Barry
B
Wise
Robert A
RA
Murray
Susan K
SK
Fishman
Alfred P
AP
Sciurba
Frank C
FC
Liberzon
Israel
I
Martinez
Fernando J
FJ
D000368:Aged; D001007:Anxiety / Q000453:epidemiology* / Q000503:physiopathology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004646:Emphysema / Q000453:epidemiology* / Q000503:physiopathology*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology*; D011788:Quality of Life; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States