COPDにおける身体活動量の低下への対応：症状認識の重要性

The importance of pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease (COPD) is well established, but improving adherence remains a challenge, particularly among patients with low physical activity (PA) despite adequate physical capacity (PC). This prospective study categorized COPD patients into 'Do do' (≥30 min/day moderate-to-vigorous PA [MVPA]) and 'Don't do' (<30 min/day MVPA) groups using Fitbit data. Baseline characteristics, pulmonary function, exercise capacity, and patient-reported outcomes (PROs)-including the mMRC, COPD Assessment Test (CAT) and Patient Health Questionnaire-9 (PHQ-9)-were assessed. Factors associated with low PA were identified by logistic regression analysis. Among the 96 patients, 44 were in the 'Do do' group and 52 in the 'Don't do' group. 'Don't do' group exhibited significantly lower 6-minute walk distance (6MWD, 424m vs. 488m, p = 0.005) and reduced pulmonary function (FEV1: 46.73% vs. 54.48%, p = 0.005), as expected. However, PRO analysis revealed that the 'Don't do' group had higher dyspnea scores (mMRC: 1.77 vs. 1.30, p = 0.019) and greater breathlessness on the CAT (OR 1.31, 95% CI 1.06-1.62), even after adjusting for 6MWD and pulmonary function. This trend persisted in the 'Can do' subgroup with high PC, indicating that dyspnea remains a major barrier to PA despite preserved PC. Low PA in COPD patients is influenced not only by PC but also by subjective symptoms such as breathlessness and fatigue. These findings highlight the importance of integrating PROs into PR assessments to identify barriers and enhance adherence. Addressing symptom burden through targeted interventions may improve PA engagement and optimize PR outcomes.