Abstract
Background: We have evaluated the impact of the frequent exacerbation phenotype and circulating systemic biomarkers in the HRQL in a well characterized cohort of COPD patients.
Methods: Data of 636 patients with stable COPD (GOLD II-IV) for ≥ 6 weeks seeking care in pulmonary tertiary care hospitals in 10 European centers were analyzed. Assessment included frequency of exacerbations in the previous year, systemic biomarkers (procalcitonin, proANP, copeptin, proadrenomedullin), lung function, SF-36, SGRQ, MMRC dyspnea score, and 6MWD test.
Results: Patients had a mean age of 66 yo ± 11; 74.1% were male; mean FEV1% pred 48.2% ± 18.5. 205 (32.3%) were current smokers and 142 (22.32%) reported frequent exacerbations (≥ 2/y). Median [95% CI] MMRC was 3 [2-3], 6MWD was 390 m [325-445]. The mean SGRQ scores were: total 43.0±38.9; symptoms 48.6±23.1, activity 57.4±23.3, and impact 32.9±19.8. In a linear, univariate regression analysis, frequent exacerbation phenotype, SaO2 at rest, desaturation (< 88%) at exercise, FEV1% pred, MMRC, 6MWD, and Borg scale, but neither current smoking nor circulating biomarkers were associated with the total SGRQ score. In the multivariate analysis, frequent exacerbation phenotype [95%] 6.55 [3.04-10.06], FEV1% pred -0.09 [-0.17–0.003], MMRC 6.46 [4.83-8.00], 6MWD -0.021 [-0.036- -0.006], Borg 1.35 [0.64-2.05] were independently associated with the HRQL as assessed by the SGRQ total score.
Conclusions: Additionally to the variables related to COPD severity, the frequent exacerbation phenotype is independently associated with the HRQL. Conversely, systemic biomarkers are not related to HRQL in COPD at stable state.
- © 2011 ERS