Relation between body mass index, forced expiratory volume in one second and 6 minute walk test in stable COPD patients

Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder characterized by irreversible, progressive airflow obstruction. It is diagnosed by spirometry which measures FEV1 and bronchoreversibility. Recent focus has been on COPD systemic effects like malnutrition, cardiovascular disorders, diabetes, musculoskeletal disorders, anxiety and depression. A composite index named BODE index (BMI, FEV1, dyspnea, 6MWT) has a better prediction of mortality than FEV1 alone in these patients. Relation between components of BODE like BMI, FEV1 and 6MWT has been an area of interest since it measures nutritional status (BMI), airway obstruction (FEV1) and exercise capacity (6MWT). We tried to evaluate the relation between lower BMI (˂21) and higher BMI groups (>21) with respect to FEV1 and 6MWT.Methods: A cross sectional observation study was conducted in a tertiary care centre. Stable patients of COPD were recruited from to outpatient department of respiratory medicine. BMI, FEV1 and 6MWT were calculated. Patients are made into 2 groups with BMI less than 21 and more than 21. Both FEV1 and 6MWT means were calculated and analyzed to find out any difference between these two groups.Results: There was no statistical difference of FEV1 and 6MWT between lower and higher BMI groups.Conclusions: In COPD patients, FEV1 and 6MWT values were not statistically different between lower and higher BMI groups. Further studies are needed to prove that other anthropometric measurement like fat free mass index can be a better substitute for more accurate assessment of exercise capacity