Six-minute walk work is not correlated to the degree of airflow obstruction in patients with Chronic Obstructive Pulmonary Disease (COPD).

Introduction: The six-minute walking test distance, despite being considered the main parameter, does not consider body weight which is known to influence exercise capacity. A body of evidence shows the degree of airflow obstruction does not correlate to walking distance and the body weight affects the work/energy required to perform the walk.

Objective: To verify if the degree of airflow obstruction correlates to six-minute walk work obtained by weight-walking distance product.

Patient And Methods: A total of 60 patients with chronic obstructive pulmonary disease were evaluated. The physiological and functional variables were correlated to distance and body weight walking distance product (WxW).

Results: There were no correlations between six- minute walk work and the degree of airflow obstruction. A positive and significant correlation were observed between the distance and Carbon Monoxide Diffusing Capacity (DLCO) (r=0.6; p<0.01) and between the distance and final SatO 2 (r= 0.3 ; p <0.05). Correlation between distance and Borg scale was negative and significant (r= -0.3; p<0.05). The six-minute walk work was positive and significantly correlated to DLCO (r= 0.7; p<0.01) and negative but significantly correlated to Borg scale in the initial (r= - 0.3; p<0.01) and final of the test (r= -0.4; p<0.05).

Conclusion: Based on this data, there was no correlation between the degree of airflow obstruction and six-minute walk work test. The DLCO was the only respiratory functional parameter significantly correlated to the distance and to the six- minute walk work.