Abstract
We assessed the 6-min walk distance (6MWD) and body weight x distance product (6MWw) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other populations. Anthropometry, spirometry, reported physical activity, and two walk tests in a 30-m corridor were evaluated in 134 subjects (73 females, 13-84 years). Mean 6MWD and 6MWw were significantly greater in males than in females (622 +/- 80 m, 46,322 +/- 10,539 kg.m vs 551 +/- 71 m, 36,356 +/- 8,289 kg.m, P < 0.05). Four equations significantly overestimated measured 6MWD (range, 32 +/- 71 to 137 +/- 74 m; P < 0.001), and one significantly underestimated it (-36 +/- 86 m; P < 0.001). 6MWD significantly correlated with age (r = -0.39), height (r = 0.44), body mass index (r = -0.24), and reported physical activity (r = 0.25). 6MWw significantly correlated with age (r = -0.21), height (r = 0.66) and reported physical activity (r = 0.25). The reference equation devised for walk distance was 6MWDm = 622.461 - (1.846 x Ageyears) + (61.503 x Gendermales = 1; females = 0); r2 = 0.300. In an additional group of 85 subjects prospectively studied, the difference between measured and the 6MWD predicted with the equation proposed here was not significant (-3 +/- 68 m; P = 0.938). The measured 6MWD represented 99.6 +/- 11.9% of the predicted value. We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes. This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases.
Highlights
The 6-min walk test (6MWT) is a simple tool for the evaluation of functional exercise capacity, which reflects the capacity of the individual to perform activities of daily living [1,2]
The equations derived from other populations commonly overestimated 6-min walk distance (6MWD) in relation to the values obtained for our subjects
Since we adhered to the guidelines for the 6MWT, established in 2002 [3], we believe that the results of the present study contribute to facilitating the international comparison of 6MWD values
Summary
The 6-min walk test (6MWT) is a simple tool for the evaluation of functional exercise capacity, which reflects the capacity of the individual to perform activities of daily living [1,2]. Demographic, anthropometric, clinical, and physiological characteristics can affect the test performance in healthy elderly subjects and in patients with cardiopulmonary diseases [3,4]. Since the 6MWT is a self-paced test, the results are influenced by external factors such as energy expenditure, operator encouragement and subject motivation. The American Thoracic Society (ATS) recommends that researchers establish specific reference values for each population [3]. Recent studies have defined 6MWT reference values for various populations [6,7,8,9,10]. Previous studies have shown that equations used in other populations are not necessarily applicable to Brazilian subjects [11,12]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Brazilian Journal of Medical and Biological Research
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
