Effect of overweight on exercise tolerance and quality of life in COPD patients

Abstract

Objective To explore overweight and obesity on pulmonary function, exercise tolerance, quality of life in COPD. Methods Patients with COPD were divided into three groups： normal body mass index （BM1） （ n = 43 ）, overweight （ n = 34） and obese （ n = 36）. Resting pulmonary function test, cardlopulmonary exercise test （CPET） and St George＇ s respiratory questionnaire （SGRQ） scores were compared during all three classes of BMI. SPSS 13.0 software was used. Results Normal BMI patients （47.28 ± 3.82） % had less FEV1/FVC compared to overweight （52. 50 ± 8.23 ） % and obese （53.20 ± 8.30 ） %, and the difference has statistically significance （F = 8.76, P 〈0.01 ）. There were significant differences in FEVI/FVC between normal BMI patients and obese （P 〈0. 01 ）, normal BMI patients and overweight（P 〈0.01 ）, but not between obese and overweight （P 〉0. 05） by multiple comparison. VO2 max/kg in normal group was （21.80 ±3.67）ml ·kg^-1·min^-1, （20.19 ＋4. 14） ml ·kg^-1·min^-1 in overweight group and （ 18.98 ±3.22） ml ·kg^-1·min^-1 in obese group, and the differences among the three group were significant （ F = 5. 82, P 〈 0. 01 ）. Multiple comparison showed no difference between normal and overweight （ P 〉 0. 05 ）, between overweight and obese group （ P 〉 0. 05 ）, but difference was significant between normal and obese （ P 〈0. 05） ; There was no difference in SGRQ score （ P 〉 0. 05）. Conclusions Weight excess may improve the airflow obstruction of resting pulmonary function test, but exercise tolerance and the airflow obstruction of CPET were worse in obese and overweight. Key words: Chronic obstructive pulmonary disease （COPD）; Resting pulmonary function test; Cardio-pulmonary exercise test （CPET） ; St George＇s respiratory questionnaire（SGRQ） ; Exercise tolerance; Quality of life