Symptom Clusters and Biomarkers in COPD
COPD patients experience high and also heterogeneous symptom burden; symptom clusters shown to have predictive value; biomarkers of inflammation may account for variation and may correlate with symptom clusters
CASCADE study: Subjects separated into symptom clusters based on: Physical: dyspnea, fatigue, pain; psychological: depression, anxiety
CASCADE evaluated association between inflammatory markers related to COPD severity or depression.
Four COPD symptom clusters identified combining high and low levels of physical symptoms, high and low levels of psychological symptoms.
CRP was the only biomarker of inflammation associated with symptom clusters and was elevated in cluster with higher burdens of both psychological and physical symptoms.
Predictors of membership in cluster with higher symptom burden: younger age, having at least a college education, oxygen use, depression
Take-home Points: COPD patients cluster into 4 symptom groups based on 5 common symptoms; CRP is the only associated inflammatory marker; young age, depression strong predictors of worse symptoms; additional research needed to confirm findings, identify mechanisms, evaluate prognostic potential
Symptom burden in COPD is high and also heterogeneous, with patients experiencing different patterns of the same symptoms, ie, dyspnea, fatigue, depression. There is some evidence to suggest that disparities in symptom experience may be related to the individual ability to respond to stress, physical and psychological, through changes in pro- and anti-inflammatory cytokines.The current study is a descriptive analysis of data from the The COPD Activity: Serotonin Transporter, Cytokines and Depression (CASCADE) cohort that is following COPD patients to better understand the biological causes and functional consequences of depression.
