[Low body mass index and exercise capacity in patients with chronic obstructive pulmonary disease (COPD)]

This study examined retrospectively the relationships between body weight and exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Seventeen patients with a %FEV1 less than 55% (mean +/- SD 36% +/- 8.8%) and minimum body weights of the body mass index (BMI) less than 20 (17.3 +/- 1.7) performed incremental exercise testing using a treadmill. Seventeen %FEV1-matched control patients with normal body weights were selected. There were no significant differences in the patients' characteristics or their pulmonary function tests (including vital capacity, carbon monoxide diffusing capacity, and arterial blood gases). Low BMI patients Is this the weaning of (67.8 +/- 6.3 years old) were younger than the control patients (73.1 +/- 8.5 years old), but the difference was not statistically significant. The exercise capacities of low BMI patients were significantly superior to those of the control patients (316.5 +/- 171.5 seconds vs 204.1 +/- 116.3 seconds, p = 0.038) and total walking distance without statistical significance (194.9 +/- 117.0 m vs 125.7 +/- 98.0 m, p = 0.071). Also, low BMI patients achieved higher maximal minute ventilation volume during exercise than the controls. The major factor limiting exercise in patients with low BMI was ventilation. Moderately low body weight may not be a risk factor in Japanese COPD patients.