Six-Minute Walk Test as a Predictive Measure of Exercise Capacity in Adults With Type 2 Diabetes

Abstract

Objective: 

The 6-minute walk test (6MWT) is a measure that is routinely used to assess a response to treatment for cardiopulmonary diseases such as pulmonary fibrosis and congestive heart failure. The measure has never been verified as a valid measure of exercise capacity in the highly prevalent patient population of type 2 diabetes (T2DM). This study investigated the correlation between the 6MWT and graded exercise testing (GXT) in an effort to validate the 6MWT as a quality tool for assessing exercise capacity in adults with T2DM.

Research Design and Method: 

This is a secondary data analysis of Program ACTIVE II, a randomized controlled trial designed to assess the effectiveness of 2 behavioral interventions on depression and glycemic outcomes in adults with T2DM. The correlation of 6MWT and predicted VO2 max (PVO2M) using GXT was examined in a subsample of participants at the time of study enrollment and at postintervention.

Results: 

PVO2M showed a significant correlation with 6MWT distance both at baseline (r = 0.57, P = .014) and postintervention (r = 0.66, P = .037). The regression analysis of baseline data revealed that 6MWT distance alone explained 45% (F = 13.03, P = .0024) of the variability in PVO2M. When combined with the SF-12 physical health component score (Physical Components Subscale [PCS]), 6MWT explained 66% (F = 13.62, P < .001) of the variance in PVO2M. After adjusting for PCS, 6MWT distance explained an additional 30% variability in PVO2M.

Conclusions: 

Findings from this study indicate that the 6MWT and predicted exercise capacity are significantly correlated. The 6MWT can be used to estimate exercise capacity in adults with T2DM.