Abstract
BACKGROUND: Arginine vasopressin modulates fluid homeostasis and oxidative stress in COPD. Levels of copeptin, a surrogate for the mature protein, at severe exacerbation are associated with survival and exacerbation rate. We hypothesize that copeptin might also be associated with clinical relevant outcomes if assessed in COPD at stable state.
METHODS: We prospectively evaluated 638 patients with stable COPD for ≥ 6 weeks, > 10 PY and GOLD II-IV seeking care in pulmonary tertiary hospitals in 8 European countries and included in the PROMISE cohort. Circulating biomarkers were assessed at baseline, at exacerbation and at biannual visits. The primary outcome of the study was exacerbation and/or death. Median observation time was 24 months.
RESULTS: Baseline copeptin levels were neither associated to time to next exacerbation (HR 0.998 95% CI 0.991-1.005) or severe exacerbation (HR0.999 95% CI 0.988-1.011), nor with the annual exacerbation rate (β -0.082 95% CI -0.573-0.002) or severe exacerbation rate (β 0.004 95% CI -0.107-0.118). Conversely, copeptin was significantly associated with mortality. The hazard ratio for death conferred by an increase of 1 pmol in copeptin was 1.016 (1.009-1.022, p<0.0001). After adjustment for the BODE-index (HR 1.348 95% CI 1.181-1.539), adjusted Charlson score (HR 1.128 95% CI 0.944-1.349) and annual exacerbation rate (HR 1.051 95%CI 0.849-1.301), log copeptin (HR 2.373 95% CI 1.078-5.223) remained significantly associated with survival.
CONCLUSION: Circulating copeptin is associated with mortality irrespectively of exacerbation rate in stable COPD.
- © 2014 ERS