Validity of the 6-minute walk test and step test for evaluation of cardio respiratory fitness in patients with type 2 diabetes mellitus

[PURPOSE]: The purpose of this study was to evaluate the reliability, reproducibility, and validity of the 6-minute walk test and step test as substitutes for ergometer exercise in patients with type 2 diabetes mellitus. [METHODS]: The study included 54 women aged 50–70 years who had type 2 diabetes mellitus. All the patients performed a cycle ergometer-graded exercise test for cardiorespiratory fitness ([Formula: see text]), followed by 6-minute walk and step tests. [RESULTS]: The mean distance covered during the 6-minute walk test was 538 ± 54 m, and the mean recovery heart rate after the step test was 93 ± 11 beats/min. A significant correlation was found between the distances covered during the cardiorespiratory fitness test ([Formula: see text]) and those covered the 6-minute walk test (r = 0.542, p < 0.01) and step test (r = −0.490, p < 0.01) in the patients with type 2 diabetes mellitus. Regression equations for the prediction of [Formula: see text] were constructed from the distance covered, heart rate, age, weight, height, fasting blood glucose level, 2-hour postprandial glucose level, and glycated hemoglobin level during the 6-minute walk test and step test. [CONCLUSION]: The 6-minute walk and step tests are simple to perform and reliable for the evaluation of cardiorespiratory fitness in patients with type 2 diabetes mellitus.