Critical review of the equations predicting 6-minute walking distance in obese subjects

Abstract

The correlation between the 6-minute walking distance and obesity has been only partially explored. Results obtained from the existing predictive equations are influenced by a variety of factors (health status, severity of obesity, reduced muscle strength and mobility, decreased aerobic capacity, presence of comorbidities).The aim of our study was to verify, compare and discuss the 6MWD predictive capacity of the equations currently available in the literature in a sample of obese subjects.Despite similar study design, the considered articles varied with regard to the number of individuals included and to age range. None of the equations available in the literature was able to accurately predict the six-minute walked distance performed by the obese subjects involved in our study. The six-minute walked distance performed by obese subjects seems to be influenced by other factors than the variables included in the equations from the literature, suggesting that they may not thoroughly capture the complexity of disability in obese people. Future research should be designed in order to validate population-specific equations, by including variables related to clinical, functional, and psychological areas, which are usually impaired in obese individuals.

Reference Equation for the Six-Minute Walk Test in Brazilian Patients with Obesity

“…A greater number of variables introduced in the equation, as already pointed out by other authors, (14,20) could provide a better evaluation from a purely mathematical point of view. On the other hand, this study would lose in practicality, since a greater number of variables would lead to a greater complexity in the collection of data in an outpatient environment of basic health care.…”

“…The use of the 6MWT for the evaluation of obese patients has recently been observed, as shown in different already published studies. [12][13][14][15] Thus, this study aims to establish a reference equation for the distance predicted in 6MWT in obese Brazilian patients.…”

Validation of the Italian version of the Laval questionnaire: health-related quality of life in subjects with obesity

“…rising from a couch, getting onto a high stool and taking objects from a cupboard or picking them up from the floor), outdoor activities (i.e. lifting and carrying bags, walking for 100 m and standing in a queue) and occupational activities are frequent in subjects with obesity [34–43]. …”

Effects of pre‐surgical aerobic dance‐based exercise on lower extremity in people with morbid obesity awaiting bariatric surgery: Randomized controlled study

“…6MWT is easy to apply, better tolerated than other walking tests, and reflects daily activities. 21 The Stair Climbing Up-Down Test (SCT) was used to evaluate the functional capacity of the individuals. Nine steps up-down total time was recorded.…”

“…The 6MWT was used to evaluate the functional capacity of the individuals as the primary outcome measure. 6MWT is easy to apply, better tolerated than other walking tests, and reflects daily activities 21 …”