Published in:
Open Access 01-12-2017 | Research
Serum bilirubin and the risk of chronic obstructive pulmonary disease exacerbations
Published in: Respiratory Research | Issue 1/2017
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Background
Bilirubin is a potent anti-oxidant and higher serum concentrations of bilirubin have been associated with better lung function, slower lung function decline, and lower incidence of chronic obstructive pulmonary disease (COPD). We sought to determine whether elevated bilirubin blood concentrations are associated with lower risk for acute exacerbations of COPD (AECOPD).
Methods
We performed a secondary analyses of data in the Simvastatin for Prevention of Exacerbations in Moderate-to-Severe COPD (STATCOPE) and the Azithromycin for Prevention of Exacerbations of COPD (MACRO) studies. We used time-dependent multivariable Cox proportional hazards analyses, using bilirubin concentrations prior to first AECOPD as the exposure variable and time to first AECOPD as the outcome variable. STATCOPE was used for model development, with validation in MACRO.
Results
In STATCOPE (n = 853), higher bilirubin was associated with a lower but statistically insignificant hazard for AECOPD, (adjusted hazard ratio [aHR] 0.89 per log10 increase [95%CI: 0.74 to 1.09; p = 0.26]). In the validation MACRO study (n = 1018), higher bilirubin was associated with a significantly lower hazard for AECOPD (aHR 0.80 per log10 increase [95%CI: 0.67 to 0.94; p = 0.008]).
Conclusions
Bilirubin may be a biomarker of AECOPD risk and may be a novel therapeutic target to reduce AECOPD risk.
Trial registrations
ClinicalTrials.gov NCT01061671 (registered 02 February 2010) and ClinicalTrials.gov NCT00325897 (registered 12 May 2006).