ObjectiveBased on real-word data, and compared with two common chronic respiratory diseases, interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD), this case-control study plans to investigate the risk factors and clinical characteristics of patients with combined pulmonary fibrosis and emphysema syndrome (CPFE).MethodsA retrospective case-control study was carried out to screen the clinical data of 96 patients with CPFE, 133 patients with COPD and 164 patients with ILD, analyze their demographics, clinical data, complications and related clinical indicators. Univariate analysis was used to compare the differences among the three groups, and multivariate logistic analysis was used to screen for risk factors.ResultsAll three groups were in old age with the average age of above 71 years. In terms of male ratio and smoking rate, the CPFE group (93.8%, 85.4%) was higher than the ILD group (75.0%, 64.0%), but there was no significant difference when compared with the COPD group (90.2%, 82.0%). Regarding comorbid disease, the proportion of connective tissue disease (CTD) in the CPFE group (10.4%) and the ILD group (13.4%) was higher than that in the COPD group (1.5%). The proportion of hyperlipidemia in the CPFE group (8.3%) was higher than that in the COPD group (1.5%) and the ILD group (1.2%). There were differences in the abnormal proportion of antinuclear antibody among the three groups, but no significant difference was found when compared with the CPFE group alone. The CPFE group (46.9%, 12.5%) and the ILD group (54.9%, 9.8%) were significantly higher than the COPD group (34.6%, 2.3%) in terms of carcinoembryonic antigen (CEA) abnormal proportion and cancer rate. In terms of the prevalence of pulmonary hypertension, the CPFE group (41.7%) > the COPD group (33.1%) > the ILD group (32.9%) was shown, but no statistical significance was found among the three groups.ConclusionsMale and smoking are not only risk factors for COPD but also for CPFE. At the same time, the suffering of CPFE may be affected by immune factors and hyperlipidemia. The proportion of CPFE patients complicated with cancer and CEA abnormalities is higher than COPD patients. The severity of pulmonary hypertension in CPFE patients is significantly higher than the other two diseases.