A Comparison of the 6-Minute Walk Test to Treadmill Exercise Test as a Tool to Evaluate Functional Capacity in Healthy ManilaMed Employees: The CoST TET Study

Abstract

INTRODUCTION: Functional capacity is a strong predictor of mortality and nonfatal cardiovascular outcomes in both men and women with and without coronary artery disease. This study aimed to compare the distance traveled of the 6-minute walk test (6MWT) to the metabolic equivalent (MET) of the treadmill exercise test (TET) as a measure of functional capacity among healthy ManilaMed (Medical Center Manila) employees and to determine and compare the distance traveled in 6MWT and the MET of TET according to general characteristics such as age, sex, height, weight, and body mass index (BMI) as determinants of maximal walking distance and the cause of the early termination of the TET. METHODS: This was a single-center prospective cross-sectional study done at a private tertiary hospital. All participants underwent TET and 6MWT. Metabolic equivalent of TET, distance traveled in 6MWT, and the computed MET of the distance traveled were recorded and analyzed. RESULTS: Fifty healthy employees performed both the 6MWT and the TET to measure their functional capacity. Twenty-two were males, and 28 were females. The mean age was 31.80 ± 7.17 years, and the mean ± SD for BMI was 25.05 ± 4.32 kg/m2. Using 400 m as predictor of good functional capacity, the farther the distance traveled (>400 m), the higher the MET they achieved in the TET, and the lower the distance traveled (<400 m), the lower the MET achieved in the TET (t test P = 0.0125). This study also showed that more than or equal to 400- m distance traveled in the 6MWT can be used as a measure of good functional capacity in this population. However, there was a significant difference (t test P = 0.006) in the computed MET in the 6MWT in relation to the MET achieved in TET. In this study age, sex, and BMI were the predictors of the distance traveled in the 6MWT (P = 0.0049) and in the TET. CONCLUSION: The distance traveled in meters in the 6MWT can be used as an objective measure of functional capacity in healthy population, and >400-m distance can be used as a parameter of good functional capacity. The formula used to compute MET in the 6MWT is not comparable with the MET achieved in TET. Age, sex, and BMI significantly influenced the performance in the 6MWT and TET.