Analysis Of Different Phenotypic Characteristics In Chronic Obstructive Pulmonary Disease Patients With Frequent Exacerbation

Objective: There was few studies on the characteristics of frequent exacerbations in patients with different phenotypes.This study attempts to investigate the clinical differences between subjects with frequent(FE)and infrequent(i FE)exacerbation with predominant chronic bronchitis(CB),emphysema(EM)or asthma-COPD overlap syndrome(ACOS)phenotypes,in order to provide the basis for clinical treatment and management of frequent and infrequent exacerbations of patients.Methods: A total of 142 cases diagnosed as chronic obstructive pulmonary disease(COPD)which admitted to the Department of respiratory medicine in our hospital were retrospectively evaluated.The patients were divided into FE and i FE two groups according to their history of acute exacerbation,and each group was divided into different phenotypes(CB,EM,ACOS)that depended on established classification criteria,the clinical characteristics,physiological and imaging differences between different subtypes of COPD subjects with FE or i FE were compared.Results: After excluding other diseases of the lung,a total of 142 patients were enrolled in the study,including FE group(n =60)and i FE group(n = 82).Subjects with FE have longer history,larger smoking index,markedly decreased FEV1% pred and FEV1/FVC(%),higher COPD Assessment Test(CAT)score,modified Medical Research Council(m MRC)and bronchial thickening score,elevated Pa CO2 and more coronary heart disease and diabetes mellitus than subjects with i FE.CB phenotype COPD subjects with FE were notably older(P=0.003),much lower body mass index(BMI)(P=0.016),inferior FEV1%pred(P=0.004),FEV1/FVC(%)(P=0.028),higher CAT(P=0.000),m MRC(P=0.000),emphysema scores(P=0.001)and arterial blood Pa CO2(P=0.000)than subjects with i FE.Multivariate analysis showed that,FEV1%pred(OR=0.899,P=0.044)and Pa CO2(OR=1.215,P=0.017)were two independent risk factors for patients with frequent exacerbations of chronic bronchitis phenotype.EM subjects with FE was elder(P=0.012),longer history(P=0.000),inferior FEV1/FVC(%)(P=0.005),higher CAT(P=0.000)and m MRC scores(P=0.000)than subjects with i FE,CAT(OR=2.601,P= 0.001)is an independent risk factor for for this group of patients.Except for a significant decrease of p H value in arterial blood gas analysis among FE patients(P = 0.032),there was no significant difference of ACOS phenotype COPD with FE and i FE in the clinical,physiological,and radiographic parameters(P > 0.05).Conclusion: The clinical features of different phenotypes in chronic obstructive pulmonary disease patients with frequent exacerbation may have their different characteristics.To make clear the clinical,physiological and imaging characteristics of patients with different phenotypes of frequent and infrequent exacerbation will be helpful to provide more personalized treatment and more targeted management programs for the patients.