Figure 4
From: Stage-dependent association of BDNF and TGF-β1with lung function in stable COPD

Correlation of Serotonin (5-HT) with FEV1 (forced exspiratory volume in 1 second) in COPD patients. Shown are correlations between serum levels of Serotonin (ng/ml) and FEV1 for all COPD patients and subjects with COPD stage GOLD III. Each dot represents one patient; the line is the regression line calculated with SPSS (Chicago, Illinois, USA). Spearman’s rank correlation coefficient (r) and the significance of the correlation (p) are given in the graph.