Analysis Of Influencing Factors Of Symptom Clusters In Patients With Chronic Obstructive Pulmonary Disease And Their Association With Inflammatory Biomarkers

Objective: To describe the symptoms in patients with chronic obstructive pulmonary disease(COPD),to explore symptom clusters and their influencing factors,and determine the relationships between inflammatory biomarkers and symptom clusters,with a view to providing reference for targeted interventions.Methods: Patients with COPD were investigated by the demographic and clinical characteristics questionnaire,the Modified Medical Research Council(mMRC),Charlson Comorbidity Index(CCI)and the Revised Memorial Symptom Assessment Scale(RMSAS).Symptoms presented in ≥ 25% of the patients were subjected to exploratory factor analyses(EFAs)to identify symptom clusters.With an entrance criterion of 0.05 and a removal criterion of 0.1,multivariate linear regressions analysis was applied to analyze which characteristics might be predictors of the symptom clusters.The association of symptom clusters and inflammatory cytokines(e.g.,C-reactive protein,procalcitonin,and erythrocyte sedimentation rate,et al.)was determined using Spearman’s coefficient.Results: 1.A total of 202 patients participated in this study.The incidence rates of 19 symptoms ranged from 5.0% to 98.5%,of which 12 were greater than50%.The most commonly occurring symptom was cough(98.5%),followed by difficulty sleeping(97.0%),shortness of breath(96.0%),feeling nervous(93.6%),and worrying(92.6%).The scores occurrence of symptoms were between 0.05 and 2.92.The top five most frequently occurring symptoms were shortness of breath 2.92(2.22,3.62),cough 2.81(2.27,3.24),lack of energy 2.49(1.66,3.23),difficulty sleeping 2.32(1.66,2.87),and feeling nervous 2.07(1.40,2.65).The scores severity of symptoms were between 0.11 and 2.50.Shortness of breath was rated as the most severe 2.50(1.71,3.25),cough 2.46(1.79,3.07),lack of energy2.07(1.24,2.79),difficulty sleeping 1.99(1.31,2.67),and worrying 1.64(0.98,1.40)were rated as most severe after shortness of breath.The scores distress of symptoms were between 0.08 and 2.90.The top five most distressing symptoms were shortness of breath 2.90(2.14,3.61),cough 2.70(2.06,3.42),difficulty sleeping 2.34(1.46,2.97),lack of energy 2.33(1.28,3.15),feeling nervous1.69(0.81,2.58).2.Three symptom clusters were identified through factor analysis: fatigue related cluster(i.e.,dry mouth,lack of energy,feeling nervous,irritable,difficulty sleeping,difficulty concentrating,and “I don’t look like myself),emotional cluster(i.e.,feeling sad,and worrying),respiratory functional cluster(i.e.,shortness of breath,cough and feeling drowsy).The incidence rates of symptom clusters were 27.72%,82.18%,and 60.40%,respectively.And the scores severity of symptom clusters were 9.00(7.00,10.00),2.00(1.00,3.00),and 5.00(3.00,7.00),respectively.3.Univariate analysis showed that the difference in BMI and lung function grading lead to the difference in the severity of fatigue-related symptom cluster(P<0.01 for all);the difference in education level,monthly income,disease duration,lung function grading,and mMRC grading lead to the difference in the severity of emotional symptom cluster(P<0.05 for all);the severity of respiratory symptom cluster differed depending on the BMI,CCI,duration,lung function grading,and mMRC grading(P<0.05 for all).4.Results of multiple linear regression analysis of symptom clusters in patients with COPD4.1 The BMI and lung function grading were the main influencing factors of fatigue related cluster.The lower the BMI,the greater the severity of the symptom cluster;in the pulmonary function classification,patients with pulmonary function grade 4 had the highest severity score of symptoms,followed by those with pulmonary function grade 3.4.2 Our study indicated that education level,lung function grading and mMRC grading were predictive factors of emotional symptom cluster.The lower the education level,the greater the severity of the symptom cluster.In the lung function classification,the severity of emotional symptom cluster of patients with the lung function grade 4 was rated as the most severe,followed by those with lung function grade 3.In the mMRC classification,the severity of symptom cluster of patients with mMRC grading 3 was rated as most severe after those with mMRC grading 4.4.3 The main influencing factors of respiratory functional cluster were BMI,CCI,disease duration,and lung function grading.The lower the BMI,the higher the CCI score,the shorter the disease duration,and the higher the lung function grade,the higher severity score of the symptom cluster.5.Correlation analysis found that CRP had a significant positive correlation with fatigue related symptom cluster and emotional symptom cluster(r =0.352,and 0.327;P<0.01 for all);and PCT,NE,and EOS had a light correlation with respiratory functional symptom cluster(r = 0.333,0.309,and 0.297,respectively;P<0.01 for all).Conclusion: Patients with COPD experienced complicated symptoms.Symptoms are categorized into fatigue related,emotional,and respiratory functional,are influenced by education level,complexity of diseases and severity of disease,and are associated with increases in markers of systemic inflammation.Targeted measures should be taken based on characteristics of these patients to ameliorate symptom burden and improve quality of life.