There are limited longitudinal studies reporting predictive factors for decline in 6-min walk distance (6MWD) in patients with COPD. While previous studies have confirmed the association between air-flow limitation and decline in 6MWD, other factors have not been clarified. The objective of this study was to investigate whether exercise-induced oxygen desaturation (EID) could be a predictive factor for decline in 6MWD in patients with COPD. The interactive effect of air-flow limitation on the association between EID and decline in 6MWD was also investigated.
METHODS:
A longitudinal observational study was conducted with 71 out-patients with COPD who were followed for 1 year. 6MWD, EID, spirometry, and clinical characteristics were assessed. The effect of EID on changes in 6MWD was examined using linear regression analyses. Furthermore, the subjects were categorized into 4 groups according to their EID and air-flow limitation status, and changes in 6MWD were compared among the groups.
RESULTS:
51 subjects completed the follow-up assessments, and 29 (56.9%) experienced EID. Multiple linear regression model revealed that EID was the only predictive factor for changes in 6MWD after adjusting for confounders (β = −38.9, P = .02). As results of multiple comparisons among the 4 groups based on EID and air-flow limitation status, changes in 6MWD in the EID and severe air-flow limitation group were the lowest.
CONCLUSION:
Our results revealed that EID was a predictive factor for decline in the functional capacity of subjects with COPD. The assessment of EID and air-flow limitation would thus be useful in estimating the prognosis of decline in the functional capacity of patients with COPD.
NiciL, DonnerC, WoutersE, ZuwallackR, AmbrosinoN, BourbeauJ, et al. American Thoracic Society/European Respiratory Society statement on pulmonary rehabilitation. Am J Respir Crit Care Med, 2006; 173(12):1390–1413.
2.
CelliBR, CoteCG, MarinJM, CasanovaC, Montes de OcaM, MendezRA, et al. The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease. N Engl J Med, 2004; 350(10):1005–1012.
3.
SpruitMA, PolkeyMI, CelliB, EdwardsLD, WatkinsML, Pinto-PlataV, et al. Predicting outcomes from 6-minute walk distance in chronic obstructive pulmonary disease. J Am Med Dir Assoc, 2012; 13(3):291–297.
4.
Pinto-PlataVM, CoteC, CabralH, TaylorJ, CelliBR. The 6-min walk distance: change over time and value as a predictor of survival in severe COPD. Eur Respir J, 2004; 23(1):28–33.
5.
CasanovaC, CoteCG, MarinJM, de TorresJP, Aguirre-JaimeA, MendezR, et al. The 6-min walking distance: long-term follow up in patients with COPD. Eur Respir J, 2007; 29(3):535–540.
6.
FriskB, EspehaugB, HardieJA, StrandLI, Moe-NilssenR, EaganTM, et al. Physical activity and longitudinal change in 6-min walk distance in COPD patients. Respir Med, 2014; 108(1):86–94.
7.
CortopassiF, CelliB, DivoM, Pinto-PlataV. Longitudinal changes in handgrip strength, hyperinflation, and 6-minute walk distance in patients with COPD and a control group. Chest, 2015; 148(4):986–994.
8.
DiazAA, Pinto-PlataV, HernandezC, PenaJ, RamosC, DiazJC, et al. Emphysema and DLCO predict a clinically important difference for 6MWD decline in COPD. Respir Med, 2015; 109(7):882–889.
9.
RamonMA, Gimeno-SantosE, FerrerJ, BalcellsE, RodriguezE, de BatlleJ, et al. Hospital admissions and exercise capacity decline in patients with COPD. Eur Respir J, 2014; 43(4):1018–1027.
10.
StolzD, BoersmaW, BlasiF, LouisR, MilenkovicB, KostikasK, et al. Exertional hypoxemia in stable COPD is common and predicted by circulating proadrenomedullin. Chest, 2014; 146(2):328–338.
11.
van GestelAJ, ClarenbachCF, StowhasAC, TeschlerS, RussiEW, TeschlerH, et al. Prevalence and prediction of exercise-induced oxygen desaturation in patients with chronic obstructive pulmonary disease. Respiration, 2012; 84(5):353–359.
12.
KimC, SeoJB, LeeSM, LeeJS, HuhJW, LeeJH, et al. Exertional desaturation as a predictor of rapid lung function decline in COPD. Respiration, 2013; 86(2):109–116.
13.
CasanovaC, CoteC, MarinJM, Pinto-PlataV, de TorresJP, Aguirre-JaimeA, et al. Distance and oxygen desaturation during the 6-min walk test as predictors of long-term mortality in patients with COPD. Chest, 2008; 134(4):746–752.
14.
TakigawaN, TadaA, SodaR, DateH, YamashitaM, EndoS, et al. Distance and oxygen desaturation in 6-min walk test predict prognosis in COPD patients. Respir Med, 2007; 101(3):561–567.
15.
WaatevikM, JohannessenA, Gomez RealF, AanerudM, HardieJA, BakkePS, et al. Oxygen desaturation in 6-min walk test is a risk factor for adverse outcomes in COPD. Eur Respir J, 2016; 48(1):82–91.
16.
AndrianopoulosV, FranssenFM, PeetersJP, UbachsTJ, BukariH, GroenenM, et al. Exercise-induced oxygen desaturation in COPD patients without resting hypoxemia. Respir Physiol Neurobiol, 2014; 190:40–46.
17.
OkiY, KanekoM, FujimotoY, SakaiH, MisuS, MitaniY, et al. Usefulness of the 6-minute walk test as a screening test for pulmonary arterial enlargement in COPD. Int J Chron Obstruct Pulmon Dis, 2016; 11:2869–2875.
18.
GolpeR, Perez-de-LlanoLA, Mendez-MaroteL, Veres-RacamondeA. Prognostic value of walk distance, work, oxygen saturation, and dyspnea during 6-minute walk test in COPD patients. Respir Care, 2013; 58(8):1329–1334.
19.
AndrianopoulosV, WoutersEF, Pinto-PlataVM, VanfleterenLE, BakkePS, FranssenFM, et al. Prognostic value of variables derived from the six-minute walk test in patients with COPD: results from the ECLIPSE study. Respir Med, 2015; 109(9):1138–1146.
20.
KentBD, MitchellPD, McNicholasWT. Hypoxemia in patients with COPD: cause, effects, and disease progression. Int J Chron Obstruct Pulmon Dis, 2011; 6:199–208.
21.
ReganEA, LynchDA, Curran-EverettD, CurtisJL, AustinJH, GrenierPA, et al. Clinical and radiologic disease in smokers with normal spirometry. JAMA Intern Med, 2015; 175(9):1539–1549.
22.
HarveyBG, Strulovici-BarelY, KanerRJ, SandersA, VincentTL, MezeyJG, et al. Risk of COPD with obstruction in active smokers with normal spirometry and reduced diffusion capacity. Eur Respir J, 2015; 46(6):1589–1597.
23.
LutchmedialSM, CreedWG, MooreAJ, WalshRR, GentchosGE, KaminskyDA. How common is airflow limitation in patients with emphysema on CT scan of the chest?. Chest, 2015; 148(1):176–184.
24.
ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med, 2002; 166(1):111–117.
25.
PuhanMA, ChandraD, MosenifarZ, RiesA, MakeB, HanselNN, et al. The minimal important difference of exercise tests in severe COPD. Eur Respir J, 2011; 37(4):784–790.
26.
HollandAE, HillCJ, RasekabaT, LeeA, NaughtonMT, McDonaldCF. Updating the minimal important difference for six-minute walk distance in patients with chronic obstructive pulmonary disease. Arch Phys Med Rehabil, 2010; 91(2):221–225.
27.
PolkeyMI, SpruitMA, EdwardsLD, WatkinsML, Pinto-PlataV, VestboJ, et al. Six-minute-walk test in chronic obstructive pulmonary disease: minimal clinically important difference for death or hospitalization. Am J Respir Crit Care Med, 2013; 187(4):382–386.
28.
AlbertRK, AuDH. Blackford air-flow limitation, CasaburiR, CooperJAJr, CrinerGJ, et al. A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation. N Engl J Med, 2016; 375(17):1617–1627.
29.
ParshallMB, SchwartzsteinRM, AdamsL, BanzettRB, ManningHL, BourbeauJ, et al. An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea. Am J Respir Crit Care Med, 2012; 185(4):435–452.
30.
Garcia-TalaveraI, GarciaCH, MacarioCC, de TorresJP, CelliBR, Aguirre-JaimeA. Time to desaturation in the 6-min walking distance test predicts 24-hour oximetry in COPD patients with a PO2 between 60 and 70mmHg. Respir Med, 2008; 102(7):1026–1032.
31.
ScottAS, BaltzmanMA, ChanR, WolkoveN. Oxygen desaturation during a 6-min walk test is a sign of nocturnal hypoxemia. Can Respir J, 2011; 18(6):333–337.
32.
PanosRJ, EschenbacherW. Exertional desaturation in patients with chronic obstructive pulmonary disease. COPD, 2009; 6(6):478–487.
33.
ZafarMA, TsuangW, LachL, EschenbacherW, PanosRJ. Dynamic hyperinflation correlates with exertional oxygen desaturation in patients with chronic obstructive pulmonary disease. Lung, 2013; 191(2):177–182.
34.
HernandesNA, WoutersEF, MeijerK, AnnegarnJ, PittaF, SpruitMA. Reproducibility of 6-minute walking test in patients with COPD. Eur Respir J, 2011; 38(2):261–267.
