Impact of Bronchiectasis on Exacerbations and Mortality in Chronic Obstructive Pulmonary Disease

• Main Authors: Ting-Chun Chou, 周亭君
• Other Authors: Yueh-Ching Chou
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/75utzf

碩士 === 國立陽明大學 === 藥理學研究所 === 105 === Background: Chronic obstructive pulmonary disease (COPD) accounts for a leading cause of morbidity and mortality in the world which brings about a significant economic burden. A high prevalence of bronchiectasis is identified by computed tomography (CT) among patients with COPD, especially in moderate-to-severe stages. COPD and bronchiectasis share many characteristics, including chronic cough and incompletely reversible airway obstruction. Previous studies have shown the presence of bronchiectasis is associated with more severe airway obstruction, more frequent exacerbations, and an increased risk of mortality. Coexisting COPD and bronchiectasis may represent a distinct phenotype which may have an implication for worse prognosis. However, no data has assessed the effect of bronchiectasis on exacerbation rates in patients with COPD in Taiwan. Studies to evaluate the treatment strategies for patients with COPD and bronchiectasis are also lacking. Therefore, the aim of this study was to investigate the influence of coexisting bronchiectasis on COPD exacerbations and mortality and evaluate the effect of its treatment in patients with COPD and bronchiectasis. Method: We conducted a retrospective cohort study using data from the Taiwan National Health Insurance Research Database between 2000 and 2011. The newly diagnosed COPD patients who aged 40 years and older and received COPD medications from 2000 to 2009 were identified. In the COPD cohort, patients were diagnosed with bronchiectasis as the exposure cohort, and the first diagnosis date was defined as the index date. Patients without performing chest X-ray or CT prior to diagnosis of bronchiectasis were excluded. The comparison cohort was matched from those COPD patients without bronchiectasis at a 1:4 ratio, according to age (±2 years), sex, and the index year. Patients were followed until death, termination of health insurance coverage, or December 31, 2011. The frequency of exacerbations and treatment during exacerbations were recorded. COX proportional hazard regression was used to analyze the risk of acute exacerbation and mortality for bronchiectasis, and evaluate the effect of bronchodilators and treatment with anti-inflammatory potential on the risk of exacerbation for patients with bronchiectasis and COPD. Results: A total of 4,152 subjects were included. Among them, 831 COPD patients with newly diagnosed bronchiectasis were identified, and 3,321 COPD patients without bronchiectasis were matched. During the follow-up period, the rate of moderate-to-severe and severe exacerbations were more frequent in patients with bronchiectasis than in those without bronchiectasis, with rate ratios of 3.42 (95% confidence interval [CI], 3.17-3.68; P < 0.0001) and 3.14 (95% CI, 2.72-3.61; P < 0.0001), respectively. Furthermore, the mutivariable Cox regression analysis revealed that the presence of bronchiectasis was independently associated with increased risks of moderate-to-severe exacerbation (hazard ratio [HR], 2.17; 95% CI, 1.85-2.53; P < 0.0001), severe exacerbation (HR, 1.81; 95% CI, 1.46-2.25; P < 0.0001) and mortality (HR, 1.47; 95% CI, 1.24-1.73; P < 0.0001). In addition, among patients with coexisting bronchiectasis and COPD, the adjusted HR for exacerbations in patients using long-acting muscarinic antagonist (LAMA) was 2.37 (95% CI, 1.33-4.21; P = 0.0033) and in patients using methylxanthines was 2.00 (95% CI, 1.52-2.63; P < 0.0001), but the adjusted HR for exacerbations in patients taking co-medication with mucolytic agents and statins was 0.49 (95% CI, 0.38-0.63; P < 0.0001) and 0.40 (95% CI, 0.27-0.60; P < 0.0001), respectively. Conclusion: The presence of bronchiectasis in patients with COPD was associated with more frequent and severe exacerbations, and increased risks of mortality. Among patients with coexisting bronchiectasis and COPD, taking co-medication with mucolytic agents or statins was associated with decreased risk of exacerbation. Further prospective studies are warranted to confirm the effect of bronchodilators and treatment with anti-inflammatory potential in patients with bronchiectasis and COPD.