PGF and chronic obstructive pulmonary disease: After adjusting for sex, age, medications, and smoking status, significant factors including advanced COPD status (forced expiratory volume in one second (FEV1) less than 40% of predicted) (odds ratio (OR) 2.2, 95% confidence interval (CI): 1.1-6.9), ICS prescription (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.3-8.7), the presence of diabetes mellitus (DM) (OR 2.6, 95% CI: 1.2-9.4) and PlGF level over 40 pg/L (OR 4.1, 95% CI: 1.5-9.9) (p < 0.01) were identified.