Reference values for the 6-Min Walking Test in obese subjects

Abstract

A reference equation specific for the obese population was provided; it can be used as realistic benchmark in the rehabilitation setting to assess functional capacity, plan exercise intensity and monitor changes over time.

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

“…Indeed, obese participants walked 81.9% and morbidly obese only 64.6% of the distance lean women were able to walk. Despite similar study sample characteristics and methods [23] (Italian subjects admitted to a Rehabilitation Unit devoted to the management of functional and clinical complications of obesity, with similar BMI and gender distribution), our results are not consistent with those provided by Capodaglio et al [29]. Discrepancies might be due to the higher mean age in our study (10 years higher), the lower track length (20 m in our study versus 30 m), as well as the lower workload in our study.…”

“…Few studies have explored the performance during the 6MWT in obese subjects [28][29][30][31]. Despite high reproducibility, results from these studies are influenced by a wealth of factors, including health status, severity of obesity, reduced muscle strength and mobility, decreased aerobic capacity and presence of comorbidities, with special regard to pulmonary and cardiovascular diseases.…”

“…The equations that we selected in the existing literature (Enright et al [18], Capodaglio et al [29] and Chetta et al [34]) do not appear to reliably predict the distance walked during the 6MWT when applied to obese subjects. According to the data obtained in our study, significant differences emerged between the distance walked by obese individuals in our sample and the distance estimated using the equations above mentioned.…”

“…Predictive equations applied to the experimental sample performing the 6MWT were the followings: [34]) The selection of the equations was based on the following considerations: i) the equations by Enright et al [18], although not very recent, were selected because they have been considered as the reference equations for the 6MWT in many papers; ii) the equation by Chetta et al [34] has been chosen because it has been validated in the Italian population; iii) the equation by Capodaglio et al [29] was included because, besides having been validated in the Italian population, considers a large sample of obese subjects (the only other equation validated in obese individuals [31] was developed using a sample of 43 subjects). …”

“…Original Article studies are reported in Table 1. In particular, two equations [29,31] had been specifically developed for obese subjects, while in other eight studies [18,26,[35][36][37][38][39][40] both obese (BMI ≥30 kg/m 2 ) and non-obese subjects were enrolled. In four papers [20,25,34,41] no information was available with respect to the presence or absence of obese subjects in the study sample.…”