title: Six-minute walk test: reference values for healthy adults in Brazil.
abstract: OBJECTIVE
  To develop regression equations for six-minute walk distance (6MWD) in healthy adults (20-80 years of age) in Brazil.
  
  
  METHODS
  We included 132 volunteers (66 males) without respiratory disease, cardiac disease, or comorbidities that affect ambulation. The volunteers completed three six-minute walk tests. Prior to and at the end of each test, we obtained SpO2 and maximal HR, as well as the Borg scale scores for sensation of dyspnea and lower limb fatigue. The data included in the final analysis were derived from the test with the greatest 6MWD.
  
  
  RESULTS
  The mean 6MWD values were 566 ± 87 m and 538 ± 95 m in males and females, respectively (p = 0.08). The 6MWD was greater in taller individuals and decreased in parallel with increases in age or body index mass (BMI). The best adjusted model was the quadratic model. We derived the following equation (valid for both genders): 6MWD = 511 + stature² (cm) × 0.0066 - age² × 0.030 - BMI² × 0.068. This equation explained 55% of the variance in 6MWD.
  
  
  CONCLUSIONS
  Reference values explaining a high proportion of the variance were derived by a quadratic regression model in healthy adults (of a wide range of ages) in Brazil.
authors: Pulmonary Function Laboratory of the Respiratory Diseases Department, São Paulo Hospital for State Civil Servants, São Paulo, Brazil. mrsoares2010@gmail.com
authors: Maria Raquel
authors: MR
authors: Soaresa
authors: Carlos Alberto de Castro
authors: CA
authors: Pereira
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001938:Brazil; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012044:Regression Analysis; D012737:Sex Factors; D013997:Time Factors; D016138:Walking / Q000502:physiology; D055815:Young Adult