Six-Minute Walk Distance in a Healthy Middle-Aged Iranian Population

The predictive equation of the six-minute walk test designed for one population cannot reliably be used for another population. Despite introducing multiple prediction equations, there is no local such equation for our country, Iran, presently.

In this cross-sectional study, we included 116 (65 males) healthy Iranian adult subjects to measure six-minute walk distance (6MWD), define influential factors, and formulate a native predictive equation. All the studied cases aged between 20 to 50 years old. We performed 6MWT according to the guideline of American Thoracic Society.

The mean value of 6MWD was 629.98 ± 81.38 meters, (ranged 421 to 729). On average, men walked 114.29 meters more than women that was statistically significant. Moreover, 6MWD had a direct correlation with subjects’ height (r = 0.627, P < 0.001); however, it had an inverse correlation with their age (r = -0.303, P < 0.001) and weight (r = -0.218, P = 0.019). Multiple regression equation derived this formula: 6MWD = 485.25 – (99.42 × sex male = 0, female = 1) + (2.791 × height cm) – (1.614 × weight) – (1.273 × age year), which explained 61% of variability. We observed that most other countries’ predictive equations could not be reliably applied to our population.

In this study, we measured 6MWD in a healthy middle-aged Iranian population and proposed a native predictive equation, which might trigger further research and application of this simple and inexpensive test in our country.