Use of Peak Oxygen Consumption in Predicting Physical Function and Quality of Life in COPD Patients

ObjectiveTo determine whether peak oxygen consumption (Vo2peak) adds to the power of FEV1 in predicting physical function and quality of life in COPD patients.DesignSingle-center cross-sectional study.MethodsSubjects included 291 COPD patients who completed pulmonary function testing, a graded exercise test, a 6-min walk, and stair climb test to assess physical function; a questionnaire assessing self-reported physical function; and a disease-specific, health-related quality-of-life questionnaire. Hierarchical multiple regression analysis was used to determine the contribution of Vo2peak in predicting physical function and quality of life after accounting for FEV1.ResultsAfter accounting for FEV1, Vo2peak added significantly to the prediction of 6-min walk distance (R2 increased by 0.395 [p < 0.005]); stair climb time (R2 increased by 0.262 [p < 0.005]); self-reported function (R2 increased by 0.109 [p < 0.005]); and health-related quality-of-life domain of mastery (R2 increased by 0.044 [p < 0.005]). Only Vo2peak was found to significantly predict the health-related quality-of-life domain of fatigue (R2 = 0.094 [p < 0.005]).ConclusionAfter controlling for FEV1, Vo2peak adds significantly to the prediction of physical function and health-related quality-of-life domain of mastery in COPD patients. These results provide additional support for the use of Vo2peak in the multidimensional assessment of COPD patients.