Use of 6-minute walk test for assessing severity of interstitial lung disease: an observational study 6MWT for assessing severity of ILD

Main Article Content

Zhan-Wei Hu
Li Gao
Qing Yu
Zhe Jin
Ju-Hong Liu
Yuan-Yuan Lian
Cheng-Li Que

Keywords

interstitial lung disease, pulmonary function test, quantitative CT, 6-minute walk test

Abstract

Background: The 6-minute walk test (6MWT) is a potential tool for assessing the severity of interstitial lung disease (ILD). Objectives: To explore the relationship between 6MWT results and traditional measures including pulmonary function and chest computed tomography(CT) and to determine factors that might influence the 6-minute walk distance (6MWD). Methods: Seventy-three patients with ILD were enrolled at Peking University First Hospital. All patients underwent 6MWT, pulmonary CT, and pulmonary function tests and their correlations were analyzed. Multivariate regression analysis was used to identify factors that might impact 6MWD.  Results: Thirty (41.4%) of the patients were female and the mean age was 66.1 ± 9.6 years. 6MWD was correlated with forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), total lung capacity (TLC), diffusing capacity for carbon monoxide (DLCO) and DLCO%pred. The decrease in oxygen saturation (SpO2) after the test was correlated with FEV1%pred, FVC%pred, TLC, TLC%pred, DLCO, DLCO%pred and the percentage of normal lung calculated by quantitative CT. The increase in Borg dyspnea scale was correlated with FEV1, DLCO and the percentage of normal lung. The backward multivariate model (F = 15.257, P < 0.001, adjusted R2 = 0.498) indicated that 6MWD was predicted by age, height, body weight, increase in heart rate, and DLCO. Conclusions: The 6MWT results were closely correlated with pulmonary function and quantitative CT in patients with ILD. However, in addition to disease severity, 6MWD was also influenced by individual characteristics and the degree of patient effort, which should thus be considered by clinicians when interpreting 6WMT results.

Abstract 398 | PDF Downloads 382

References

1. Travis WD, Costabel U, Hansell DM, et al; ATS/ERS Committee on Idiopathic Interstitial Pneumonias. An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classification of the idiopathic interstitial pneumonias. Am J Respir Crit Care Med. 2013;188(6):733-48.
2. Takizawa A, Kamita M, Kondoh Y, Bando M, Kuwana M, Inoue Y. Current monitoring and treatment of progressive fibrosing interstitial lung disease: a survey of physicians in Japan, the United States, and the European Union. Curr Med Res Opin. 2021;37(2):327-339.
3. Chetta A, Aiello M, Foresi A, et al. Relationship between outcome measures of six-minute walk test and baseline lung function in patients with interstitial lung disease. Sarcoidosis Vasc Diffuse Lung Dis. 2001;18(2):170-5.
4. Alhamad EH, Cal JG. Predictors of mortality in interstitial lung disease patients without pulmonary hypertension. Ann Thorac Med. 2020;15(4):238-243.
5. Lancaster LH. Utility of the six-minute walk test in patients with idiopathic pulmonary fibrosis. Multidiscip Respir Med. 2018;13:45.
6. 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):111-7.
7. Chen A, Karwoski RA, Gierada DS, Bartholmai BJ, Koo CW. Quantitative CT Analysis of Diffuse Lung Disease. Radiographics. 2020;40(1):28-43.
8. Graham BL, Steenbruggen I, Miller MR, et al. Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement. Am J Respir Crit Care Med. 2019;200(8):e70-e88.
9. Kim HJ, Brown MS, Chong D, et al. Comparison of the quantitative CT imaging biomarkers of idiopathic pulmonary fibrosis at baseline and early change with an interval of 7 months. Acad Radiol. 2015;22(1):70-80.
10. Bartholmai BJ, Raghunath S, Karwoski RA, et al. Quantitative computed tomography imaging of interstitial lung diseases. J Thorac Imaging. 2013;28(5):298-307.
11. Capaccione KM, Wang A, Lee SM, et al. Quantifying normal lung in pulmonary fibrosis: CT analysis and correlation with %DLCO. Clin Imaging. 2021;77:287-290.
12. Kaya F, Özgül E, Balcı A. Quantitative and visual analysis of idiopathic pulmonary fibrosis with different methods: the relationship between clinical correlation and mortality risk model. Eur Rev Med Pharmacol Sci. 2021;25(8):3254-3263.
13. Barros MC, Hochhegger B, Altmayer S, et al. The Normal Lung Index From Quantitative Computed Tomography for the Evaluation of Obstructive and Restrictive Lung Disease. J Thorac Imaging. 2022;37(4):246-252.
14. Cazzoletti L, Zanolin ME, Dorelli G, et al. Six-minute walk distance in healthy subjects: reference standards from a general population sample. Respir Res. 2022;23(1):83.
15. Casanova C, Celli BR, Barria P, et al. The 6-min walk distance in healthy subjects: reference standards from seven countries. Eur Respir J. 2011;37(1):150-6.
16. Halliday SJ, Wang L, Yu C, et al. Six-minute walk distance in healthy young adults. Respir Med. 2020;165:105933.
17. Weir NA, Brown AW, Shlobin OA, et al. The influence of alternative instruction on 6-min walk test distance. Chest. 2013;144(6):1900-1905.
18. Khor YH, Farooqi M, Hambly N, et al. Trajectories and Prognostic Significance of 6-Minute Walk Test Parameters in Fibrotic Interstitial Lung Disease: A Multicenter Study. Chest. 2023;163(2):345-357.