Abstract
Background: Irisin is a novel hormone-like myokine with a highly controversial physiological role and potential therapeutic value.
Aims and objectives: The aim of our study was to investigate if serum levels of irisin are associated with exacerbations of COPD and furthermore to validate irisin as a circulating biomarker for COPD progression and severity.
Methods: We prospectively evaluated 638 patients with stable COPD, GOLD II-IV, >10 PY from 8 European countries, included in the PROMISE cohort. The primary outcome of the study was exacerbation and/or death. Median observation time was 24 months. Serum levels of irisin were measured at baseline by ELISA.
Results: Serum irisin levels were not associated with the age or the BMI of the patients, the 6 MWD or the BODE index. However, irisin was significantly associated with the BORG scale (OR 0.125 95%CI 0.101-0.728 p=0.010) and negatively associated with FEV1% pred (OR -0.104 95%CI -0.020-0.00 p=0.026). Furthermore, serum irisin levels at baseline were significantly higher in patients with severe exacerbations as compared with patients without severe exacerbations (1480μg/ml±121 vs 1265μg/ml±88, p=0.009). Irisin was associated significantly (p=0.004) with the number of severe exacerbations per year (OR 0.134 95% CI 0.051-0.269). Logistic (OR 1.589 95% CI 1.076-2.347, p=0.020) and linear multivariate analysis (β 0.158 95% CI 0.027-0.289, p=0.019) revealed that these associations were independent of adjusted Charlson score, 6 MWD, FEV1% pred and diabetes.
Conclusions: Our results indicate that irisin may prove to be a useful systemic biomarker to predict severe exacerbations in COPD.
- Copyright ©ERS 2015