Exposing Pre-Chronic Obstructive Pulmonary Disease: When Physiology Matters!

Chronic Bronchitis Affects Outcomes in Smokers without Chronic Obstructive Pulmonary Disease (COPD)

Background. Chronic bronchitis (CB) importantly affects outcomes in smokers with COPD, but the effects on smokers without COPD are less well known and less emphasized. The aim of our study was to investigate the possible effects of CB on clinical outcomes in smokers without COPD (noCOPD) and compare them with the effects in smokers with COPD (COPD). Methods. For that purpose, we studied 511 smokers, 302 with and 209 without COPD, followed for 10 years in an academic COPD ambulatory setting. Chronic bronchitis was defined as the presence of cough and sputum production for at least 3 months in each of two consecutive years. All subjects underwent clinical and functional examination with spirometry, diffusion capacity (DLco), 6-min walking test (6MWT), mMRC Dyspnoea Scale, COPD Assessment Test (CAT), and recording of annual frequency of exacerbations. All-cause mortality during follow-up was recorded. Results. 27% of noCOPD and 45% of COPD had CB. noCOPD with CB had lower FEV₁ and DLco, worse 6MWT, more dyspnoea, a higher number of exacerbations and lower survival than noCOPD without CB. CB did not affect FEV₁ decline in noCOPD but it significantly did in COPD. Conclusions. The presence of chronic bronchitis in smokers without COPD will significantly affect symptoms, quality of life, and survival, underlining the importance of recognizing the condition and managing it accordingly.

Symptomatic smokers without COPD have physiological changes heralding the development of COPD

Background

COPD is a major health problem, mainly due to cigarette smoking. Most studies in COPD are dedicated to fully developed COPD in older subjects, even though development of COPD may start soon after smoking initiation. Therefore, there is a need to diagnose this “early disease” by detecting the initial events responsible for ultimate development of COPD.

Methods

Measurement of maximum mid expiratory flow between 25 and 75% of vital capacity (MMEF) in a routine spirometry, which detects small airways disease, was used to investigate if MMEF abnormalities in smokers without COPD (noCOPD) would relate to respiratory symptoms and identify smokers that might progress to COPD. For this purpose we studied 511 smokers, 302 COPD and 209 noCOPD, followed long term with spirometry including MMEF, diffusing capacity of the lung for carbon monoxide (D_LCO), 6-min walk test (6MWT), Medical Research Council Dyspnoea Scale and COPD Assessment Test. Three spirometries V1,V2 and V3 (5±2.5 and 10±4 years apart from V1) were performed to assess functional decline and development of COPD.

Results

65% of noCOPD had an abnormal MMEF (<80%) and 38% an abnormal D_LCO. The NoCOPD with MMEF <80% group performed worse in the 6MWT (p=0.01), was more dyspnoeic (p=0.01) and had higher prevalence of chronic bronchitis than the noCOPD with MMEF>80% group (p=0.04). 21% of noCOPD with MMEF <80% and 2.7% with MMEF>80% developed COPD by V3 (p=0.0004).

Conclusions

The MMEF, a functional test available in a routine spirometry, can detect early lung abnormalities and identify the subset of symptomatic smokers with pathological changes that might lead to COPD.

In symptomatic smokers with normal FEV₁/FVC, an abnormal FEF_25–75% (MMEF), which reflects early lung abnormalities, could be used as a biomarker for disease progression and impending risk of COPD developmenthttps://bit.ly/39y0smC