Clinical Significance Of Serum Cystatin-c In Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Objective Chronic obstructive pulmonary disease(COPD)is a commonly encountered chronic disease of the respiratory system,with high disability and mortality,which brings a heavy burden to the society and the family.The diagnosis of acute exacerbation of chronic obstructive pulmonary disease in the past is mainly based on the aggravation of the symptoms and the lack of objective diagnosis.Cystatin-C is a common biochemical marker.The purpose of this study is to investigate the clinical significance of cystatin-C in Chronic obstructive pulmonary disease acute exacerbation(AECOPD).Methods This experiment adopts the retrospective analysis of clinical information,collected from January 2017 to April 2017 in our hospital diagnosed AECOPD and 73 cases as AECOPD group,select the same period in outpatients with stable patients with COPD diagnosis of 30 cases as a stable group,select the same period examination center health examination in 30 cases as healthy control group.AECOPD group of patients admitted to hospital without oxygen extraction when the radial artery blood 2ml,on the second day of fasting venous blood 3ml,arterial partial pressure of carbon dioxide(PCO2),partial pressure of oxygen(PO2),oxygen saturation(Sp O2),venous blood Cys-C,WBC and neutral ratio,CRP value,stable condition after the use of me Institute of pulmonary function testing of FEV1Pred%,FEV1/FVC,echocardiography and pulmonary artery pressure was measured by ultrasound in our hospital;In stable phase,the 3ml of fasting elbow blood was taken on the day of the outpatient clinic,and the 3ml of fasting elbow vein blood was taken on the day of physical examination.Blood Cys-C,WBC,neutral ratio and CRP value were measured.FEV1Pred% and FEV1/FVC were measured on the same day by our lung function tester.The three groups of other data(age,body mass index,sex,smoking index,hospitalization time,hospitalization cost)were measured and recorded by the members of the experimental group.The differences in age,body mass index,sex,smoking index,Cys-C,WBC,neutral ratio,CRP and FEV1Pred% were compared in the three groups.The patients in group AECOPD were divided into GOLD II,GOLD III and GOLD IV grades according to the GOLD classification of lung function.The differences of Cys-C,WBC,neutral ratio and CRP were compared between the three groups.The correlation between Cys-C and PO2,PCO2,Sp O2,pulmonary arterial pressure,time of hospitalization and hospitalization cost in group AECOPD was analyzed.To make an analysis of the Cys-C curve(ROC curve)of the pulmonary arterial pressure,the diagnostic value of Cys-C for chronic obstructive pulmonary disease(COPD)with pulmonary hypertension was determined.Results 1.there was no significant difference in age,sex,smoking history and BMI(P > 0.05)in the three groups.The smoking index in the healthy control group was lower than that in the stable period group and the acute exacerbation stage,with a statistically significant difference(P < 0.05).The FEV1Pred% in the healthy control group was higher than that in the stable period group and the acute exacerbation stage,with a statistically significant difference(P < 0.05).There was no significant difference in the smoking index and FEV1Pred% between the stable group and the acute exacerbation group(P > 0.05).2.Cys-C in AECOPD group was higher than that in stable phase group Cys-C,while Cys-C in healthy control group was lower than that in stable phase group(1.12 ± 0.03 VS 0.74 ±0.03 VS 0.89 ±0.03),and there was a significant difference(P < 0.05).In group AECOPD,WBC,neutral ratio and CRP were all higher than those in stable group and healthy control group,with statistical difference(P < 0.05).There was no significant difference in WBC,neutral ratio and CRP between stable phase group and healthy control group(P > 0.05).3.There were significant differences in GOLD II,GOLD III and GOLD IV Cys-C(0.94± 0.02 VS 1.15 ± 0.02 VS 1.44 ± 0.04),there was a significant difference among groups(P < 0.05),but there was no significant difference in blood WBC,neutral ratio and CRP between three groups(P > 0.05).4.there was a negative correlation between Cys-C and PO2,Sp O2(r=-0.280,p=0.016;r=-0.293,p=0.012),a positive correlation between Cys-C and PCO2,pulmonary arterial pressure,time of hospitalization,and hospitalization costs(r=0.636,P < 0.001;r=0.578,P < 0.001;r=0.390,p=0.001;r=0.414,P < 0.001)in group AECOPD.5.The area under the Cys-C curve of ROC(AUC=0.866,P < 0.001),the ROC curve of cystatin-C with maximum Youden index cutoff point of 1.2250mg/L,sensitivity and specificity were 95.7% and 74.1%,when more than 1.2250mg/L group serum cystatin-C level in acute exacerbation,that patients with COPD combined with pulmonary artery high pressure.Conclusion The increase of serum Cys-C level has clinical significance in patients with acute exacerbation of chronic obstructive pulmonary disease.It can be used as a reference index for diagnosis and severity grading of acute exacerbation of chronic obstructive pulmonary disease.