26 October 2018
We aimed to study the adverse outcomes of symptomatic and asymptomatic non-obstructed individuals and those with mild COPD longitudinally in participants from three Latin-American cities.
Two population-based surveys of adults with spirometry were conducted for these same individuals with a 5- to 9-year interval. We evaluated the impact of respiratory symptoms (cough, phlegm, wheezing or dyspnea) in non-obstructed individuals, and among those classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1, COPD on exacerbation frequency, mortality and FEV 1 decline, compared with asymptomatic individuals without airflow obstruction or restriction.
Non-obstructed symptomatic individuals had a marginal increased risk of mortality (HR 1.3; 95% CI 0.9–1.94), increased FEV 1 decline (−4.5 mL/year; 95% CI −8.6, −0.4) and increased risk of 2+ exacerbations in the previous year (OR 2.6; 95% CI 1.2–6.5). Individuals with GOLD stage 1 had a marginal increase in mortality (HR 1.5; 95% CI 0.93–2.3) but a non-significant impact on FEV 1 decline or exacerbations compared with non-obstructed individuals.
The presence of respiratory symptoms in non-obstructed individuals was a predictor of mortality, lung-function decline and exacerbations, whereas the impact of GOLD stage 1 was mild and inconsistent. Respiratory symptoms were associated with asthma, current smoking, and the report of heart disease. Spirometric case-finding and treatment should target individuals with moderate-to-severe airflow obstruction and those with restriction, the groups with consistent increased mortality.