Figure 1.

Serum levels of PAI-1 (A) in patients with COPD and controls without any lung disease (P=0.015) and (B) according to COPD severity.

Notes: After adjustment for a broad spectrum of possible confounders, PAI-1 still differed significantly between COPD patients and controls (P=0.027). After stratifying according to severity stages, PAI-1 was highest in GOLD II followed by GOLD III (*P=0.003 and **P=0.011 for the comparison with controls). Lines represent the median, boxes represent the IQR, and circles represent outliers.

Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global Initiative for Chronic Obstructive Lung Disease; IQR, interquartile range; PAI-1, plasminogen activator inhibitor-1.