Fig. 1

Confirmation and metabonomics of COPD patients. Typical Computed Tomography (CT) of COPD patients (A) and healthy people (B). Parameters of CT analysis of COPD patients: Total Emphysema Volume (TEV) (C), Total Lung Volume (TLV) (D) and Emphysemaindex (EI) (E). Pulmonary function parameters of COPD patients: Maximum Expiratory Flow (PEF) (F), Forced Vital Capacity (FVC) (G), the percentage of forced expiratory volume in the first second (FEV1%) (H). Serum cytokine levels in COPD patients by Enzyme linked immunosorbent assay (ELISA): interleukin-1β (IL-1β) (I), interleukin-6 (IL-6) (J), tumor necrosis factor-α (TNF-α) (K). The Top 50 differential metabolites were identified and the results are shown in the form of heat map: the red part represents metabolites with relatively high content, and the green part represents metabolites with relatively low content (L). (n = 211 for COPD patients and n = 60 for healthy people). All data were presented as mean ± SD. Compared with healthy people: ^##P < 0.01