Comorbidity and Inflammatory Markers May Contribute to Predict Mortality of High-Risk Patients With Chronic Obstructive Pulmonary Disease Exacerbation

BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease (COPD) causes not only an accelerated disease progression, but also an increased mortality rate. The purpose of this study was to analyze the factors associated with clinical features, comorbidities and mortality in patients at high risk for acute COPD exacerbation who had been hospitalized at least once in a year. METHODS The study enrolled 606 patients who had been diagnosed with and were being treated for COPD at university affiliated hospital. Among them, there were 61 patients at high risk for acute exacerbation of COPD who had been hospitalized at least once in a year. A retrospective analysis was conducted to examine the factors affecting mortality. The analysis divided the patients into non-survivor and survivor groups, and reviewed their medical records for clinical aspects, comorbidities, pulmonary function tests and blood tests. RESULTS In the high-risk group, the number of comorbidities at diagnosis (P = 0.020) and the Charlson comorbidity index value (P = 0.018) were higher in the non-survivor group than in the survivor group. During hospitalization, the non-survivor group had a significantly higher neutrophil (%) and a significantly lower lymphocyte (%) in complete blood count. Under stable conditions, the high-sensitivity C-reactive protein (hsCRP) concentration in blood plasma and neutrophil (%) were significantly higher (P = 0.025 and P = 0.036), while the lymphocyte (%) was significantly lower (P = 0.005) in the non-survivor group. A pulmonary function test revealed no statistically significant differences between the two groups. CONCLUSION The number of comorbidities, neutrophil (%), lymphocyte (%) in complete blood cell (CBC) and hsCRP in blood plasma concentration among the groups at high risk for COPD exacerbation are associated with increased mortality.