Correlation of Spirometry with the Six-minute Walk Test in Eutrophic and Obese Individuals

Objective: To assess the distance covered by both eutrophic individuals and individuals with different grades of obesity and correlate the data obtained with spirometric values. This study is justified by the existing difficulty in assessing the functional capacity in obese individuals, and by the low cost and good specificity of six-minute walk test (6MWT) in predicting reduced capacity for activities of daily living for any individual.

Methods: One hundred fifty-four individuals of both genders were assessed after being divided into two groups: G1, obese individuals (n = 93, BMI ≥ 30 kg/m²) and G2, eutrophic individuals (n = 61, BMI 18.5 to 24.99 kg/m²). The 6MWT was performed using the methodology described by the American Thoracic Society (ATS-2002). Spirometry was performed both before and after the application of a bronchodilator agent (BDA) in accordance with the Guidelines for Pulmonary Function Tests by the Brazilian Society of Pneumology and Phthisiology (SBPT-2002). The statistical analysis, consisting of mean, standard deviation, Pearson's correlation, Student's t test and Spearman's correlation, considered p < 0.05.

Results: The 6MWT analysis with spirometry for G1 was positively correlated only with pre- and post-BDA peak expiratory flow rate (PEFR).

Conclusion: The present study showed a positive correlation between pre- and post-BDA PEFR and the distance covered in the 6MWT in obese subjects, that is, the higher the PEFR, the higher the physico-functional capacity of the individual, and consequently, the greater the distance covered.