Characteristics and Quality of Life of Patients with COPD with Different Degrees of Exercise-Induced Desaturation on Six-minute Walk Test.
To identify predictive factors for different exercise-induced desaturation (EID) severities and evaluate health-related quality of life six months later in chronic obstructive pulmonary disease (COPD) patients.
This retrospective study consecutively analyzed 116 COPD outpatients (male: 82.8% [96/116]; age: 63.48 ± 7.48 years; disease severity distribution: GOLD 1/2/3/4 = 55.8%/34.6%/7.7%/1.9%). Patients were categorized into three groups based on oxygen desaturation (SpO2) during the six-minute walk test (6MWT): non-EID (n = 52), mild-EID (n = 42), and severe-EID (n = 22). EID was classified as follows: Mild EID: SpO2 decrease ≥4% with nadir SpO2 ≥90%. Severe EID: SpO2 decrease ≥4% with nadir SpO2 ≤90%. Non EID: SpO2 decrease <4% with nadir SpO2 ≥90%. A six-month follow-up was conducted via telephone to record adverse events and assess quality of life using the Chinese version of the EQ-5D questionnaire, which includes five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, along with the EQ-VAS scale.
Significant differences were observed across the three groups in peripheral blood oxygen saturation (SpO2, %), peak expiratory flow (PEF, L/s), PEF (%), forced expiratory volume in the first second (FEV1, L), FEV1 (%), 6MWT distance (6MWD, m), Borg dyspnea, and Borg fatigue scores. The optimal cutoff values for predicting EID severity was 54.45% for FEV1% (AUC=0.716), 450.5 m for 6MWD (AUC = 0.761), and 94.5% for resting SpO2 (AUC = 0.737). Multivariate logistic regression analysis identified low FEV1%, reduced 6MWD, and low resting SpO2 as risk factors for severe EID (FEV1%: p = 0.002; 6MWD: p = 0.008; SpO2: p = 0.018. Severe EID patients had significantly lower EQ-5D index and EQ-VAS scores (EQ-5D index: p = 0.002; EQ-VAS: P = 0.005), particularly in mobility and usual activities dimensions (mobility: p = 0.001; usual activities: p = 0.038).
Low FEV1%, reduced 6MWD, and low resting SpO2 are key risk factors for severe EID, provide practical thresholds for clinical management of EID in COPD patients.
This retrospective study consecutively analyzed 116 COPD outpatients (male: 82.8% [96/116]; age: 63.48 ± 7.48 years; disease severity distribution: GOLD 1/2/3/4 = 55.8%/34.6%/7.7%/1.9%). Patients were categorized into three groups based on oxygen desaturation (SpO2) during the six-minute walk test (6MWT): non-EID (n = 52), mild-EID (n = 42), and severe-EID (n = 22). EID was classified as follows: Mild EID: SpO2 decrease ≥4% with nadir SpO2 ≥90%. Severe EID: SpO2 decrease ≥4% with nadir SpO2 ≤90%. Non EID: SpO2 decrease <4% with nadir SpO2 ≥90%. A six-month follow-up was conducted via telephone to record adverse events and assess quality of life using the Chinese version of the EQ-5D questionnaire, which includes five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, along with the EQ-VAS scale.
Significant differences were observed across the three groups in peripheral blood oxygen saturation (SpO2, %), peak expiratory flow (PEF, L/s), PEF (%), forced expiratory volume in the first second (FEV1, L), FEV1 (%), 6MWT distance (6MWD, m), Borg dyspnea, and Borg fatigue scores. The optimal cutoff values for predicting EID severity was 54.45% for FEV1% (AUC=0.716), 450.5 m for 6MWD (AUC = 0.761), and 94.5% for resting SpO2 (AUC = 0.737). Multivariate logistic regression analysis identified low FEV1%, reduced 6MWD, and low resting SpO2 as risk factors for severe EID (FEV1%: p = 0.002; 6MWD: p = 0.008; SpO2: p = 0.018. Severe EID patients had significantly lower EQ-5D index and EQ-VAS scores (EQ-5D index: p = 0.002; EQ-VAS: P = 0.005), particularly in mobility and usual activities dimensions (mobility: p = 0.001; usual activities: p = 0.038).
Low FEV1%, reduced 6MWD, and low resting SpO2 are key risk factors for severe EID, provide practical thresholds for clinical management of EID in COPD patients.
Authors
Gao Gao, Wang Wang, Zhao Zhao, Liao Liao, Qumu Qumu, Wang Wang, Yang Yang, Jiang Jiang
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