Lung function and onset of cardiometabolic diseases in the longitudinal Burden of Obstructive Lung Disease (BOLD) study

The aim of this study was to assess the longitudinal association between lung function and the onset of cardiometabolic diseases across sites in low-, middle- and high-income countries. The study population comprised 5,916 individuals from 15 countries participating in BOLD baseline and follow-up assessments. At baseline, post-bronchodilator forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC were measured. Participants who reported having doctor-diagnosed hypertension, diabetes, heart disease and stroke at follow-up but not at baseline were considered new cases of these diseases. The association between lung function and onset of cardiometabolic diseases was assessed in each site using regression models, and estimates were combined using random effects meta-analysis. Participants with higher FVC (as % predicted value) were less likely to have new-onset diabetes (OR per 10% predicted = 0.91, 95%CI 0.84-0.99), heart disease (OR per 10% = 0.86, 95%CI 0.80-0.92) and stroke (OR per 10% = 0.81, 95%CI 0.73-0.89) during the follow-up period (mean ±SD 9.5±3.6 years). A higher FEV₁ was associated with a lower risk of onset of heart disease and stroke. No significant association was found between FEV₁/FVC and new onset of cardiometabolic diseases, except for a higher risk of diabetes (OR per 10% = 1.21, 95%CI 1.08-1.35). The findings of this study suggest that a low FVC is more important than a low FEV₁/FVC as a risk factor for developing cardiometabolic diseases. The potential value of including FVC in risk score models to improve their precision in predicting the onset of cardiometabolic diseases should be explored.