Does 1-minute walk test predict results of 6-minute walk test in patients with interstitial lung diseases?

Abstract

Background Six-minute walk test (6MWT) is well-established in assessing functional capacity and exercise-induced oxygen desaturation. For some patients, 6MWT may be very exhausting and shorter-duration test would likely be less time-consuming and easier. Aim To investigate if 1-minute walk test (1MWT) predicts the results of 6MWT test as regards the exercise capacity, exercise-induced oxygen desaturation, and symptoms in patients with interstitial lung diseases (ILDs). Patients and methods Thirty patients with ILD were recruited from a university hospital between April 2019 and June 2019. Demographics data were collected. Spirometry, 6MWT, and 1MWT were performed. Total walking distance, oxygen saturation decline, heart rate recovery, dyspnea, and leg fatigue were evaluated. Results Out of 30 cases studied, 22 (73.3%) were females and eight (26.7%) were males. The mean age was 51.9 ± 13.86, mean BMI 28.32 ± 5.55, and mean forced vital capacity 47.27 ± 14.65 l/m. The mean walking distance of 1MWT and 6MWT were 46.43 ± 9.97 and 269 ± 76.94, respectively. There was a statistically significant positive correlation between 1MWT and 6MWT regarding walking distance, heart rate recovery, dyspnea at the end of the test (Borg scale), leg fatigue at the end of the test (Borg scale), and oxygen saturation decline. No adverse events related to both walking tests were recorded. Conclusion 1MWT can predict results of 6MWT in ILD patients as regards exercise capacity, exercise-induced oxygen desaturation, and symptoms. 1MWT might serve as a practical substitute for the more cumbersome 6MWT.