Cardiorespiratory responses to 6-minute walk test in interstitial lung disease: not always a submaximal test

Abstract

BACKGROUND: The 6-minute walk test (6 MWT) is used to measure exercise capacity and assess prognosis in interstitial lung disease (ILD). Although the 6 MWT is usually considered to be a test of submaximal exercise capacity in ILD, the physiological load imposed by this test is not well described and 6 MWT outcomes are poorly understood. This study aimed to compare cardiorespiratory responses to 6 MWT and cardiopulmonary exercise test (CPET) in people with ILD. METHODS: 47 participants with ILD (27 idiopathic pulmonary fibrosis (IPF), mean age 71 (SD 12) years, diffusing capacity for carbon monoxide (TLCO) 49(15) %predicted) undertook CPET and 6 MWT on the same day in random order. Oxygen upt..