Fig. 1
From: The matrikine acetyl-proline-glycine-proline and clinical features of COPD: findings from SPIROMICS
Associations between AcPGP and COPD severity. Log-transformed AcPGP in A) sputum was significantly higher in GOLD 3/4 COPD compared to GOLD 1 or 2 but there were no differences in plasma AcPGP across spirometric GOLD stages. 1-way ANOVA with Tukey’s post-hoc testing was used for analyses; *P = 0.0019 between GOLD 1 and GOLD 3/4; **P < 0.0001 between GOLD 2 and GOLD 3/4