Effectiveness of Pulmonary Rehabilitation in Exercise Capacity and Quality of Life in Chronic Obstructive Pulmonary Disease Patients With and Without Global Fat-Free Mass Depletion

Abstract

ObjectiveTo investigate the effectiveness of pulmonary rehabilitation (PR) in exercise capacity and quality of life in patients with chronic obstructive pulmonary disease (COPD) with and without global fat-free mass (FFM) depletion. DesignRetrospective case-control. SettingOutpatient clinic, university center. ParticipantsCOPD patients (N=102) that completed PR were initially evaluated. InterventionPR including whole-body and weight training for 12 weeks, 3 times per week. Main Outcome MeasuresSt. George Respiratory Questionnaire (SGRQ), 6-minute walk distance (6MWD), and FFM evaluation applied before and after PR. ResultsPatients were stratified according to their FFM status measured by bioelectric impedance. They were considered depleted if the FFM index was ≤15kg/m2 in women and ≤16kg/m2 in men. From the initial sample, all depleted patients (n=31) composed the FFM depleted group. It was composed predominantly by women (68%) with a mean age ± SD of 64.4±7.3 years and a forced expiratory volume in 1 second of 33.6%=−13.2% predicted. Paired for sex and age, 31 nondepleted patients were selected from the initial sample to compose the nondepleted group. Improvement in the 6MWD was similar in these 2 groups after PR. Both groups improved SGRQ scores, although the observed power was small and did not allow adequate comparison between depleted and nondepleted patients. There was no difference between groups in weight change, whereas FFM tended to be greater in depleted patients. This increase had no correlation with the 6MWD or the SGRQ. ConclusionsBenefits of PR to exercise capacity were similar comparing FFM depleted and nondepleted COPD patients. Although FFM change tended to be greater in depleted patients, this increase had no definite relation with clinical outcomes.