Should maximal mid-expiratory flow (MMEF) be considered more in COPD?

Abstract

Background and Aim: Although forced expiratory volume in 1 second(FEV1) and FEV1 / forced vital capacity(FVC) ratio are objective parameters in treatment follow-up, many studies proved that these parameters have a limited ability to predict clinical outcomes. Therefore, small airways dysfunction, which is determined by maximal mid‐expiratory flow (MMEF), has recently come into prominence in the literature. The aim of this study was to compare dyspnea perception, the severity of fatigue, exercise capacity and HRQoL between COPD patients with high small airways dysfunction and relatively better. Methods: The study consisted of 96 patients with moderate COPD. Pulmonary Function Tests, the six-minute walk test distance (6MWD), the modified Medical Research Council Dyspnea Scale (mMRC), International Physical Activity Questionnaire -short form (IPAQ-SF), Fatigue Severity Scale (FSS), St. George’s Respiratory Questionnaire (SGRQ) and Short Form 36 (SF-36) questionnaire were evaluated in all patients. After calculating the average of MMEF % of patients, they were divided into two groups: Below the average (Group 1, n=54) and above the average (Group 2, n=42). Results: BMI, cigarette consumption, FEV1 %, FVC %, and FEV1 / FVC ratio not statistically different between the groups (p>0.05 for all). FSS and mMRC scores were significantly higher in Group 1, however, 6MWD and IPAQ-SF scores were significantly lower in Group 1 (p Conclusion: COPD patients with high small airways dysfunction have a higher perception of dyspnea and fatigue, as well as poor exercise capacity and HRQoL.