Epidemiology and risk factors of asthma-chronic obstructive pulmonary disease overlap in low- and middle-income countries

Abstract

Background: Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents the confluence of bronchial airway hyperreactivity and chronic airflow limitation and has been described as leading to worse lung function and quality of life than found with either singular disease process.Objective: We aimed to describe the prevalence and risk factors for ACO among adults across 6 low-and middle-income countries (LMICs). Methods:We compiled cross-sectional data for 11,923 participants aged 35 to 92 years from 4 population-based studies in 12 settings. We defined COPD as postbronchodilator FEV 1 /forced vital capacity ratio below the lower limit of normal, asthma as wheeze or medication use in 12 months or self-reported physician diagnosis, and ACO as having both.

A burning need to redefine airways disease: Biomass smoke exposure identified as a unique risk factor for asthma–chronic obstructive pulmonary disease overlap in low- and middle-income countries

“…ACO epidemiology studies are scarce in LMICs, and therefore studying novel geographic regions characterized by lower income was a major strength of the study by Morgan. 9 Importantly, the present work highlights the risks and higher ACO prevalence associated with biomass fuel exposure in LMICs compared with high-income countries. Indeed, ACO might not only be more severe but also be more like COPD rather than asthma in LMICs in comparison with ACO reported in high-income nations, and biomass fuel has been identified as an important novel risk factor in the development of ACO.…”

“…Biomass smoke exposure has been associated with multiple different chronic lung diseases, including COPD, asthma, bronchitis, and interstitial lung disease to name a few. Morgan et al 9 conducted their cross-sectional investigation on a large multinational cohort of participants with asthma and COPD. To describe the prevalence of ACO risk factors among adults across 6 LMICs (Peru, Argentina, Chile, Uruguay, Bangladesh, and Uganda), the authors included 11,923 participants from 4 population-based studies in 12 different settings and reported that biomass air pollution is a novel risk factor for ACO.…”

“…To describe the prevalence of ACO risk factors among adults across 6 LMICs (Peru, Argentina, Chile, Uruguay, Bangladesh, and Uganda), the authors included 11,923 participants from 4 population-based studies in 12 different settings and reported that biomass air pollution is a novel risk factor for ACO. 9 Risk factors for ACO in high-, middle-, and lowincome countries have not been compared previously because most studies came from relatively high-income countries.…”

“…Risk factors for ACO (bubbles) from 6 major epidemiologic studies (identified by numbers in yellow squares, as listed below) are superimposed on a geographic map of the world that is colored by income group. Morgan et al 9 showed that patients with ACO from South America tended to be male and smoked more, whereas participants from Africa tended to be younger, less obese, and exposed to more biomass and have less education. Patient participants with ACO from Asia had less obesity, were exposed to more biomass smoke, and had less education than others in the study.…”

An Ophthalmic Changes in Patients with Chronic Obstructive Pulmonary Disease: Case-Control Study

“…COPD is characterized as a preventable disease with some significant extra pulmonary effects, associated with persistent, progressive, and not totally reversible airflow limitation [9][10][11]. According to the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD, 2006), the spirometric diagnostic criteria for this disease is the ratio of forced expiratory volume in the first second / forced vital capacity (FEV1 / FVC) of less than 0.7 after the bronchodilator and, depending on the degree of bronchial obstruction, patients were classified into four groups according to established spirometric criteria [12].…”