Department of Internal Medicine, Far Eastern Memorial Hospital, Pan-Chiao, Taipei, Taiwan.
BMC Pulm Med. 2011 Sep 30;11:46. doi: 10.1186/1471-2466-11-46.
An increased incidence of pneumonia in patients with chronic obstructive pulmonary disease (COPD) under inhaled corticosteroid (ICS) therapy was noticed in previous studies. We performed a prospective study to elucidate the risk factors for the development of pneumonia in this group of patients.
A prospective, non-randomized study with patients diagnosed as having COPD from 2007 to 2008 identified in the Far Eastern Memorial Hospital were recruited. We recorded data for all patients, including clinical features and signs, demographic data, lung function status, and medications. Bio-markers such as C-reactive protein (CRP) and placenta growth factor (PlGF) were checked at first diagnosis. Every acute exacerbation was also recorded, especially pneumonia events, which were confirmed by chest radiography. Multivariate analysis was performed with stepwise logistic regression for pneumonia risk factors.
274 patients were diagnosed as having COPD during the study period and 29 patients suffered from pneumonia with a prevalence of 10.6%. The rate was significantly higher in patients with ICS therapy (20/125, 16%) compared with those without ICS (9/149, 6%) (p = 0.02). We stratified ICS therapy into medium dose (500-999 ug/day fluticasone equivalent, 71 patients) and high dose (1000 ug/day and higher fluticasone equivalent, 54 patients) group. There was no statistical difference in the incidence of pneumonia between these two group (medium dose: 13/71, 18.3% vs. high dose: 7/54, 12.9%, p = 0.47). Multivariate analysis was performed to identify the risk factors for developing pneumonia and included forced expiratory volume in one second (FEV1) less than 40% of predicted (odds ratio (OR) 2.2, 95% confidence interval (CI): 1.1-6.9), ICS prescription ((OR) 2.4, 95% (CI): 1.3-8.7), the presence of diabetes mellitus (DM) (OR 2.6, 95% CI: 1.2-9.4) and PlGF level over 40 pg/L (OR 4.1, 95% CI: 1.5-9.9).
ICS therapy in patients with COPD increased the risk of pneumonia. However, there was no relationship between the incidence of pneumonia and dosage of ICS. Additionally, advanced COPD status, DM and elevated PlGF level were independent risk factors for the development of pneumonia. PlGF would be a good novel biomarker for predicting pneumonia.
在先前的研究中发现，接受吸入性皮质类固醇（ICS）治疗的慢性阻塞性肺疾病（COPD）患者肺炎发病率增加。我们进行了一项前瞻性研究，以阐明该组患者发生肺炎的危险因素。
从 2007 年至 2008 年远东纪念医院诊断为 COPD 的患者中招募了前瞻性、非随机研究的患者。我们记录了所有患者的数据，包括临床特征和体征、人口统计学数据、肺功能状况和药物治疗。首次诊断时检查了 C 反应蛋白（CRP）和胎盘生长因子（PlGF）等生物标志物。还记录了每一次急性加重的情况，特别是经胸部 X 光检查证实的肺炎事件。采用逐步逻辑回归对肺炎危险因素进行多变量分析。
在研究期间，274 例患者被诊断为 COPD，29 例患者发生肺炎，患病率为 10.6%。接受 ICS 治疗的患者（20/125，16%）明显高于未接受 ICS 治疗的患者（9/149，6%）（p=0.02）。我们将 ICS 治疗分为中剂量（500-999ug/天氟替卡松等效物，71 例）和高剂量（1000ug/天及更高的氟替卡松等效物，54 例）组。这两组肺炎发生率无统计学差异（中剂量：13/71，18.3% vs. 高剂量：7/54，12.9%，p=0.47）。进行多变量分析以确定发生肺炎的危险因素，包括一秒用力呼气量（FEV1）小于预测值的 40%（比值比（OR）2.2，95%置信区间（CI）：1.1-6.9）、ICS 处方（OR 2.4，95%CI：1.3-8.7）、糖尿病（DM）（OR 2.6，95%CI：1.2-9.4）和 PlGF 水平超过 40pg/L（OR 4.1，95%CI：1.5-9.9）。
COPD 患者的 ICS 治疗增加了肺炎的风险。然而，肺炎的发生率与 ICS 的剂量无关。此外，COPD 病情加重、DM 和 PlGF 水平升高是肺炎发生的独立危险因素。PlGF 可能是预测肺炎的良好新型生物标志物。
