Risk factors for low forced vital capacity in the multinational BOLD study: An update

Abstract

Background: Forced vital capacity (FVC) is a good predictor of all-cause mortality, yet little is known on the causes of a low FVC. Aims and Objectives: To identify risk factors for low FVC, i.e. FVC Methods: Using data from nearly 29,000 adults who participated in the Burden of Obstructive Lung Disease (BOLD) study in 41 sites across the world, we assessed the association of a low FVC with several potential risk factors (sex; age; height; history of tuberculosis (TB); own education; father’s education; body mass index (BMI); smoking status; pack-years of tobacco smoking; work in dusty jobs) using multivariable regression analysis within each site, followed by meta-analysis of all sites. Additional factors (waist-hip ratio; wealth score; mother’s education; parent’s smoking status during childhood; solid fuel use) were investigated in sites where data were available. Results: People with a history of TB (OR=1.9, 95%CI 1.4-2.6), an abnormal BMI (low: OR=2.0, 95%CI 1.7-2.5; overweight: OR=1.2, 95%CI 1.1-1.3; obese: OR=2.0, 95%CI 1.7-2.3) or a great number of pack-years ((20, 30]: OR=1.4, 95%CI 1.1-1.7; >30: OR=1.5, 95%CI 1.3-1.8) were more likely to have a low FVC. Those with a large waist-hip ratio (OR=1.3, 95%CI 1.2-1.5) were also more likely to have a low FVC. In contrast, people with a high school or university degree (OR=0.9, 95%CI 0.8-0.98) and an educated father (primary school: OR=0.9, 95%CI 0.8-0.97; high school/university: OR=0.9, 95%CI 0.8-0.95) were less likely to have a low FVC. Conclusion: In this multinational population-based cross-sectional study of adults, a low FVC was influenced by a history of TB, body mass, smoking, and own and father’s education.