Lung function decline in subjects with and without COPD in a population-based cohort in Latin-America

Abstract

BackgroundLung-function decline is one of the possible mechanisms leading to Chronic Obstructive Pulmonary Disease (COPD).MethodsWe analyzed data obtained from two population-based surveys of adults (n = 2026) conducted in the same individuals 5–9 years (y) after their baseline examination in three Latin-American cities. Post BronchoDilator (postBD) FEV1 decline in mL/y, as %predicted/y (%P/y) and % of baseline/y (%B/y) was calculated and the influence of age, gender, BMI, baseline lung function, BD response, exacerbations rate evaluated using multivariate models.ResultsExpressed in ml/y, the mean annual postBD FEV1 decline was 27 mL (0.22%P, 1.32%B) in patients with baseline COPD and 36 (0.14%P, 1.36%B) in those without. Faster decline (in mL/y) was associated with higher baseline lung function, with significant response to bronchodilators, older age and smoking at baseline, also in women with chronic cough and phlegm, or ≥2 respiratory exacerbations in the previous year, and in men with asthma.ConclusionsLung function decline in a population-based cohort did not differ in obstructed and non-obstructed individuals, it was proportional to baseline FEV1, and was higher in smokers, elderly, and women with respiratory symptoms.

Outcomes for symptomatic non-obstructed individuals and individuals with mild (GOLD stage 1) COPD in a population based cohort

“…The clinical characteristics in the two evaluations have been previously presented. 4 , 8 Compared with the first examination, individuals with a follow-up exam were older, with less current smoking, and with slightly lower lung function.…”

“…Our reference group was the non-obstructed non-restricted asymptomatic participants: those who lacked a report of cough, phlegm (both even without a cold), wheezing (in the last year) and dyspnea (dyspnea ≤1 according to the MRC scale). Adverse outcomes, especially death, 4 as well as lung-function decline, 8 were analyzed previously in detail, including the main risk factors. However, the aim of the present study was to investigate the impact of mild COPD and respiratory symptoms on decline, death and exacerbations.…”

“…The risk of death during follow-up was estimated by fitting Cox proportional-hazard models, while the risk of two or more exacerbations in the previous year was calculated by fitting a logistic regression model, and the annual decline in post-BD FEV 1 (mL/year) was calculated by subtracting the second measurement from the first and dividing the difference between the exact number of years between the two examinations 8 in a multiple linear regression model.…”

“…In the PLATINO’s longitudinal study, the FEV 1 was the main predictor of survival, 4 as well as a predictor of lung-function decline. 8 As GOLD stage 1 (mild COPD) individuals have a normal FEV 1 by definition, we would expect a mild or non-significant impact on these outcomes.…”

Gender Modifies the Effect of Body Mass Index on Lung Function Decline in Mild-to-Moderate COPD Patients: A Pooled Analysis

“…It is now well-recognized that cachexia is a signi cant risk factor for poor outcomes including mortality in COPD patients (6)(7)(8). However, while multiple studies report that those with low body mass index (BMI) may be at risk of COPD progression and those who are obese may be protected (3,4), others have shown no signi cant association between BMI and FEV 1 decline (11,12). One reason for the controversy is the fact that a decline in lung function varies according to certain factors, most notably, smoking, gender, and disease stage (5)(6)(7).…”