Hu Guoping, Wu Yankui, Zhou Yumin, Yu Yan, Liang Weiqiang, Ran Pixin
Department of Respiratory Medicine, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Department of Respiratory Disease, People's Hospital of Guangxi Zhuang Autonomous Region, Guangxi Zhuang Autonomous Region, China.
Respir Care. 2016 Jul;61(7):950-7. doi: 10.4187/respcare.04034. Epub 2016 Apr 12.
COPD is associated with cardiovascular and renal dysfunction. Cystatin C (CysC) is a biomarker of renal function and an independent risk factor for all-cause and cardiovascular mortality among elderly persons. The aim of the study was to examine the prognostic role of CysC for in-hospital mortality in subjects with a COPD exacerbation.
Upon admission, serum CysC levels and arterial blood gas analysis from 477 subjects with a COPD exacerbation were measured. Clinical characteristics were also recorded. A receiver operating characteristic curve analysis was used to determine the level of CysC that discriminated survivors from non-survivors. Univariate and multiple logistic regression analyses were used to identify the risk factors for in-hospital mortality. To reduce the influence of confounders, subgroup analyses were performed according to the comorbidities, including states of heart failure, renal dysfunction, and pH, PaCO2 , and PaO2 levels.
During the in-hospital period, 59 subjects died, and 418 subjects recovered. The decedent group showed lower pH (7.27 ± 0.17 vs 7.38 ± 0.06, P < .001), higher CysC (2.21 ± 1.05 mg/L vs 1.39 ± 0.54 mg/L, P < .001), higher PaCO2 (77 ± 39 mm Hg vs 48 ± 14 mm Hg, P < .001), and lower PaO2 (74 ± 32 mm Hg vs 84 ± 26 mm Hg, P < .001) levels. The area under the receiver operating characteristic curve for the CysC prediction of death was 0.77 (95% CI 0.70-0.84). CysC values ≥1.59 mg/L were associated with significantly higher in-hospital mortality (relative risk = 5.49, 95% CI 3.24-9.32, P < .001). Multiple logistic regression analysis showed that pH <7.20, CysC ≥1.59 mg/L, and heart failure were independent predictors of in-hospital mortality. The subgroup analysis showed that the comorbid states of renal dysfunction, congestive heart failure, and the levels of pH, PaCO2 , and PaO2 did not alter the conclusion that CysC was a mortality risk factor for subjects with a COPD exacerbation.
CysC was a strong and independent risk factor for hospital mortality secondary to COPD exacerbation.
慢性阻塞性肺疾病（COPD）与心血管和肾功能障碍相关。胱抑素C（CysC）是肾功能的生物标志物，也是老年人全因死亡和心血管死亡的独立危险因素。本研究旨在探讨CysC在COPD急性加重患者住院死亡率中的预后作用。
纳入477例COPD急性加重患者，入院时检测血清CysC水平并进行动脉血气分析，同时记录临床特征。采用受试者工作特征曲线分析确定区分存活者与非存活者的CysC水平。采用单因素和多因素logistic回归分析确定住院死亡率的危险因素。为减少混杂因素的影响，根据合并症进行亚组分析，包括心力衰竭、肾功能障碍状态以及pH、PaCO2和PaO2水平。
住院期间，59例患者死亡，418例患者康复。死亡组患者的pH值较低（7.27±0.17 vs 7.38±0.06，P<.001），CysC水平较高（2.21±1.05 mg/L vs 1.39±0.54 mg/L，P<.001），PaCO2水平较高（77±39 mmHg vs 48±14 mmHg，P<.001），PaO2水平较低（74±32 mmHg vs 84±26 mmHg，P<.001）。CysC预测死亡的受试者工作特征曲线下面积为0.77（95%CI 0.70-0.84）。CysC值≥1.59 mg/L与住院死亡率显著升高相关（相对风险=5.49，95%CI 3.24-9.32，P<.001）。多因素logistic回归分析显示，pH<7.20、CysC≥1.59 mg/L和心力衰竭是住院死亡率的独立预测因素。亚组分析显示，肾功能障碍、充血性心力衰竭的合并状态以及pH、PaCO2和PaO2水平并未改变CysC是COPD急性加重患者死亡风险因素的结论。
CysC是COPD急性加重继发医院死亡的一个强有力的独立危险因素。
