INTRODUCTION: The effect of pulmonary rehabilitation (PR) on physical activity (PA) is small. Whether the change in PA depends on the nutritional status of patients is unknown.

AIM: To evaluate change in PA after 3 months PR in patients according to body mass index.

METHODS: Patients with COPD who completed 3 months PR were divided into 4 BMI groups: underweight (UW, BMI<21kg/m²), normal weight (NW, BMI: 21-25kg/m²), overweight (OW, BMI: 25-30kg/m²) and obesity (OB, BMI>30kg/m²). All patients performed clinical tests and PA was measured by accelerometry, before and after the PR. The increase in daily step count was compared across BMI groups using One-way Anova, adjusted for baseline PA and tested the association between change in body weight (BW) and PA.

RESULTS: A total of 187 COPD patients (60% male, 65±8y, FEV₁ 46±16%pred, 6MWD 412m (65%pred)) were included. 22% of patients were UW, 30% NW, 24%OW and 24%OB. At baseline UW and OB patients showed significantly lower step count compared to NW (p<0.05). The increase in step count following PR was small in all groups (figure 1) and this was not statistically different between groups. The change in BW was associated to change in PA in NW (r=-0.28, p=0.04) but not in the other groups.

CONCLUSIONS: PR does not result in large increases in PA and this was not different across BMI groups.