TY - JOUR T1 - Relationship between plasma amino acid levels and lung function decline in patients with COPD JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - 3300 AU - Masaru Suzuki AU - Hironi Makita AU - Satoshi Konno AU - Katsura Nagai AU - Masaharu Nishimura Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/3300.abstract N2 - Introduction: We have shown that the rate of annual change in FEV1 is highly variable among patients with COPD (Nishimura, M. et al. Am J Respir Crit Care Med 2012; 185:44-52). However, few data exist on blood biomarkers predicting lung function decline in patients with COPD, while altered plasma amino acid profiles have been reported in those patients. Aim: To explore the relationship between plasma amino acid levels and an annual change in FEV1 in patients with COPD in a 5-year prospective observational cohort study. Methods: A total of 220 subjects (GOLD 1, 27%; GOLD 2, 44%; GOLD 3, 25%; GOLD 4, 5%) who participated in the Hokkaido COPD cohort study and had at least three spirometric measurements were included for this analysis. Amino acids were profiled in baseline plasma samples by the HPLC method. The annual changes in post-bronchodilator FEV1 were determined by a linear mixed-effects model. Results: Spearman’s rank correlation analysis showed that decreases in five plasma amino acid levels (taurine, proline, alanine, valine, and tyrosine), branched-chain amino acids level, and total amino acids level were significantly correlated with an annual decline in FEV1 (p<0.05). A multivariate regression analysis demonstrated that proline was the only amino acid whose decrease was significantly associated with an annual decline in FEV1 independent of body mass index. Conclusion: We found that a deceased level of plasma proline, independent of body weight loss, was significantly associated with a rapid annual decline in FEV1 in patients with COPD. The altered plasma amino acid profile may be important to predict natural history of COPD. ER -