Application Of Phenotypic Analysis In COPD And Analysis Of Clinical Characteristics And Risk Factors Of Frequently Aggravating Phenotype

Objective(s):The aim of this study was to investigate the basic clinical features and risk factors of patients with frequent exacerbations of COPD phenotype and to investigate the value of some clinical features in predicting frequent exacerbations of COPD.The study also aims to link them with imaging phenotypes,eosinophil phenotypes and comorbidity phenotypes to provide a comprehensive assessment of patients with frequent COPD exacerbations,with the aim of reducing the failure rate of disease treatment and the risk of future exacerbations.Methods:Retrospective analysis of 228 COPD patients who attended the Department of Respiratory and Critical Care Medicine at our hospital from August 2020 to August2022 were divided into frequent exacerbation phenotype group(86 cases)and infrequent exacerbation phenotype group(142 cases)according to whether the number of acute exacerbations was ≥2 in the previous year.The patients were divided into eosinophilic phenotype and non-eosinophilic phenotype according to whether the proportion of blood eosinophils to leukocytes was ≥2%,and into type A,type E,and type M according to the imaging manifestations.General information(gender,age,body mass index,smoking history,smoking index),pulmonary function index,laboratory index,comorbidity status,and treatment during hospitalization were collected.The clinical characteristics of frequent exacerbation phenotypes were studied,and binary logistic regression was used to analyze the risk factors affecting frequent exacerbations;the relationship between frequent exacerbation phenotypes and imaging phenotypes,eosinophil phenotypes and comorbidity phenotypes was analyzed;the optimal cut-off value was determined based on the ROC curve of NLR to predict the risk of frequent exacerbations in COPD patients.To explore the significance and value of common phenotypes for COPD assessment and treatment.Results:1.A total of 228 COPD patients were included in this study.The frequent exacerbation phenotype group had longer hospitalization days,lower BMI,and higher rates of hormone use,intravenous hormone use,triple inhaler use,ventilator use,and occurrence of respiratory failure during hospitalization,and the differences were statistically significant(P<0.05).2.PEF,FEV1pred%,FEV1,FVC,FEV1/FVC,FEF25,FEF50,and FEF75 were lower in the frequent exacerbation phenotype group than in the infrequent exacerbation phenotype group,and the differences were statistically significant(P<0.05).3.Lym,Lym%,EOS,EOS% of hematological indexes in the frequent exacerbation phenotype group were lower than those in the infrequent exacerbation phenotype group,while NEUT,NEUT%,WBC,,hs-CRP,PCT,IL-6,NLR,PLR were higher than those in the infrequent exacerbation phenotype group,and the differences were statistically significant(P<0.05).Pa O2 in the frequent exacerbation phenotype group was lower than that in the infrequent exacerbation phenotype group,while Pa CO2 was higher than that in the infrequent exacerbation phenotype group,and the difference was statistically significant(P<0.05).4.The difference between the frequent exacerbation phenotype group and the infrequent exacerbation phenotype group in terms of comorbidity phenotype was statistically significant only in the hypertensive disease subgroup(P<0.05).5.In terms of emphysema grading and emphysema score in the frequent exacerbation phenotype group and the infrequent exacerbation phenotype group,the emphysema grading in both groups was concentrated in grade 0-1,but the proportion of patients with emphysema grade 4 was higher in the frequent exacerbation phenotype group,and the emphysema score was also significantly higher than that in the infrequent exacerbation phenotype group;in terms of imaging phenotype,both groups were predominantly type A,but the proportions of patients with type E and type M were higher in the frequent exacerbation phenotype group than in the infrequent exacerbation phenotype group.The difference was statistically significant(P<0.05).6.The proportion of patients with eosinophilic phenotype was higher in the frequent exacerbation phenotype group than in the infrequent exacerbation phenotype group,and the difference was statistically significant(P<0.05).7.Univariate logistic regression analysis showed that BMI,combined severe airflow limitation(i.e.FEV1pred%<50%),combined respiratory failure,combined hypertension,imaging phenotypes E and M,and non-EOS phenotypes were risk factors for frequent exacerbations in COPD patients(P<0.05).Multifactorial logistic regression analysis showed that combined severe airflow limitation(OR=3.734,95%CI 1.803-7.733,P<0.001),combined respiratory failure(OR=2.703,95%CI1.340-5.451,P=0.005),combined hypertension(OR=2.029,95%CI 1.077-3.822,P=0.029),imaging phenotype E(OR=2.632,95%CI 1.162-5.963,P=0.020),and non-EOS phenotype(OR=2.550,95%CI 1.339-4.855,P=0.004)were independent risk factors for frequent exacerbations in COPD patients(P<0.05).8.NLR can be used to predict the risk of frequent acute exacerbations in COPD patients with a maximum area under the curve(AUC)of 0.709(95% CI 0.638-1.780)and a cut-off value of 3.655 for NLR when the Jorden index is maximum,with a sensitivity of 64% and specificity of 71.8%.the combination of the two indicators NLR-Emphysema score and the NLR-Emphysema score-The area under the curve was 0.743(95% CI 0.677-0.808)and 0.755(95% CI 0.693-0.818),respectively,when the three indicators of EOS were combined for prediction,and their sensitivity and specificity were 80.2% and 64.1%,84.9% and 59.9% diagnostic efficacy were improved compared to the single indicator,respectively.Conclusion(s):1.FEV1pred%<50% and combined respiratory failure were independent risk factors for the development of frequent exacerbations.2.Patients with frequent exacerbation phenotype had higher emphysema scores,emphysema grading was predominantly grade 4,and imaging phenotype E was an independent risk factor for the development of frequent exacerbations.3.The proportion of patients with a combination of frequent exacerbation phenotypes that were not EOS phenotypes was higher than that of the non-frequent exacerbation phenotype group,and the non-EOS phenotype was an independent risk factor for the occurrence of frequent exacerbations in COPD patients.4.Hypertension was the most common comorbidity in patients with frequent exacerbation phenotype and was an independent risk factor for frequent exacerbations.5.Patients in the frequent exacerbation phenotype group have higher levels of inflammation in vivo,and the novel inflammatory marker NLR has some predictive value in predicting the risk of frequent exacerbations in COPD patients,and the combined assessment with emphysema score and eosinophil count can improve the diagnostic efficacy.