Serum Bilirubin and Disease Progression in Mild Chronic Obstructive Pulmonary Disease.
Chest. 2014 Dec 24;
Authors: Apperley S, Park HY, Holmes DT, Man SF, Tashkin D, Wise RA, Connett JE, Sin DD
Abstract
Background: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder associated with oxidative stress. Serum bilirubin has potent anti-oxidant actions and higher concentrations have been shown to protect against oxidative stress. The relation between serum bilirubin and COPD progression is unknown.
Methods: Serum bilirubin was measured in 4,680 smokers aged 35-60 years old with mild to moderate airflow limitation. The relationship of serum bilirubin to post bronchodilator FEV1 and rate of FEV1 decline over three to nine years was determined using regression modeling. Total and disease-specific mortality was also ascertained.
Results: Serum bilirubin was positively related to FEV1 (p<0.001). Serum bilirubin was also negatively related to the annual decline in FEV1 when adjusted for baseline demographics, pack years smoked and baseline measures of lung function (p=0.01). Additionally, serum bilirubin was negatively associated with risk of death from coronary heart disease (p=0.03); however, the relationships between bilirubin and other mortality endpoints were not statistically significant (p>0.05).
Conclusion: Bilirubin is inversely related to COPD disease severity and progression. Higher serum bilirubin was associated with a higher FEV1 and less annual decline in FEV1. Bilirubin was also associated with less coronary heart disease mortality. These data support the hypothesis that bilirubin has a protective effect on COPD disease progression, possibly through its anti-oxidant actions. Bilirubin may prove useful as an easily accessible and readily available blood based COPD biomarker.
PMID: 25539285 [PubMed - as supplied by publisher]