Risk factors for COPD spirometrically defined from the lower limit of normal in the BOLD project

Abstract

Chronic obstructive pulmonary disease (COPD) is predicted to become the third most common cause of death and disability worldwide by 2020.The prevalence of COPD defined by the lower limit of normal was estimated using high-quality spirometry in surveys of 14 populations aged o40 yrs. The strength and consistency of associations were assessed using random effects meta-analysis.Pack-years of smoking were associated with risk of COPD at each site. After adjusting for this effect, we still observed significant associations of COPD risk with age (OR 1.52 for a 10 yr age difference, 95% CI 1.35-1.71), body mass index in obese compared with normal weight (OR 0.50, 95% CI 0.37-0.67), level of education completed (OR 0.76, 95% CI 0.67-0.87), hospitalisation with a respiratory problem before age 10 yrs (OR 2.35, 95% CI 1.42-3.91), passive cigarette smoke exposure (OR 1.24, 95% CI 1.05-1.47), tuberculosis (OR 1.78, 95%CI 1.17-2.72) and a family history of COPD (OR 1.50, 95% CI 1.19-1.90).Although smoking is the most important risk factor for COPD, other risk factors are also important. More research is required to elucidate relevant risk factors in low-and middle-income countries where the greatest impact of COPD will occur.

Noncommunicable Lung Disease in Sub-Saharan Africa. A Community-based Cross-Sectional Study of Adults in Urban Malawi

“…No association was seen in our data between moderate to severe chronic airflow obstruction and exposure to tobacco or biomass, although both are recognized risk factors for obstruction (27)(28)(29)(30). The absence of a relationship between biomass exposure and airway obstruction may be explained by limited study power related to the low prevalence of moderate to severe obstruction (3.6%), or misclassification of self-reported rather than objectively quantified biomass exposure, but it is consistent with findings of a recent population-based study in Nigeria (31,32).…”

Body mass index and chronic airflow limitation in a worldwide population-based study

“…14,15 The burden of obstructive lung disease (BOLD) initiative is an international population-based study implementing rigorous standardized methods for estimating CAL prevalence (high-quality postbronchodilator spirometry) and its risk factors. While BMI has already been described in the context of other possible risk factors for the presence of airflow limitation in BOLD, 16,17 the principal objective of the present study was to study in detail the relation between low and obese BMI and the presence of CAL in a general worldwide population, taking into account the impact of gender, smoking status, age and site-to-site heterogeneity.…”

Chronic Obstructive Pulmonary Disease: Official diagnosis and treatment guidelines of the Czech Pneumological and Phthisiological Society; a novel phenotypic approach to COPD with patient-oriented care

“…Cigarette smoking remains the most important risk factor for COPD -COPD smokers tend to have more serious symptoms, increased mortality rate and faster deterioration of lung functions than in COPD non-smokers 29 . Apart from active smoking, which is responsible for 70-80% of cases of COPD onset, the following are also generally considered risk factors: environmental tobacco smoke -ETS, cannabis smoking, cigar, pipe or water pipe smoking; prolonged exposure to industrial pollution, longterm inhalation of vehicle exhaust, burnt fossil fuel and biomass fumes, low weight at birth and frequent infections during childhood 29,30 .…”

“…Apart from active smoking, which is responsible for 70-80% of cases of COPD onset, the following are also generally considered risk factors: environmental tobacco smoke -ETS, cannabis smoking, cigar, pipe or water pipe smoking; prolonged exposure to industrial pollution, longterm inhalation of vehicle exhaust, burnt fossil fuel and biomass fumes, low weight at birth and frequent infections during childhood 29,30 . The development of the disease is determined by the specific interaction between genetic and epigenetic factors, and effects of the environment 31,32 .…”