Physiologic responses during the six minute walk test in obese and non-obese COPD patients

The mean FEV1 in the obese and non-obese groups was 52 ± 13 and 58 ± 18 percent of predicted, respectively, and the BMI of the obese patients was 37 ± 02 kg/m2. Obese patients had shorter 6 min walk distances than non-obese patients (247 ± 73 vs 348 ± 51 m, respectively, p = 0.003), but walk-work, defined as 6 min walk distance × weight (in kg), was not different. There were no significant between-group differences in any exercise variable measured during the 6 min walk test. In both groups, VO2 and VE increased linearly over the first 2-3 min, then plateaued at approximately 80% of maximum. Although 6 min walk distance is shorter in obese COPD patients, their physiologic responses are similar to those of non-obese patients.