Correlation Analysis Of Thyroid Hormone,Procalcitonin And Disease Severity And Prognosis In Elderly Patients With Pneumonia

Pneumonia is a common acute infectious disease of lower respiratory tract,and lower respiratory tract infection including pneumonia is one of the common causes of death worldwide.Severe pneumonia is the leading cause of death in infectious disease.Therefore,Timely assessment of the condition of patients with pneumonia,timely prediction of the development of the disease and early judgment of the prognosis of patients,can help patients get accurate and timely treatment,and ultimately reduce the mortality of patients,improve the level of diagnosis and treatment.Objective:To investigate the differences of the serum levels between thyroid hormone and Procalcitonin（PCT）in elderly patients with pneumonia,and to evaluate their correlation with the severity and prognosis of pneumonia.Methods:A prospective study was performed on 120 pneumonia patients diagnosed in the Department of Respiratory Medicine and intensive Care Medicine of our hospital from October 2021 to December 2022,including 59cases of common pneumonia and 61 cases of Severe pneumonia,and 51cases of normal control group were collected in the medical health examination center of our hospital during the same period.Patients with severe pneumonia were defined as having a good prognosis if they were improved and discharged within 28 days of admission.Patients with severe pneumonia were defined as having a poor prognosis if they died of pneumonia within 28 days of admission or were hospitalized for more than28 days due to pneumonia.The patients with severe pneumonia were divided into a good prognosis group（35 cases）and a poor prognosis group（26 cases）.The general information such as gender,age,smoking status,previous medical history（coronary heart disease,cerebrovascular disease,diabetes,hypertension）,admission time,hospitalization days,and discharge time.From the morning of the second day after admission,procalcitonin（PCT）,C-reactive protein（CRP）,erythrocyte distribution width（RDW）,central granulocyte count（N）,lymphocyte count（L）,neutrophil to lymphocyte ratio（NLR）,lactate（Lac）,thriod-stimulatinghormone（TSH）,tetraiodothyronine（T₄）,triiodothyronine（T₃）,free tetraiodothyronine（f T₄）,free triiodothyronine（f T₃）,total protein（TP）and albumin（ALB）were collected.SPSS 26.0 software was used for statistical analysis.The measurement data with normal distribution were expressed as（?）±s.One-way ANOVA was used for making a comparison among the normal control group,common pneumonia group and severe pneumonia group,and LSD-t test was used for comparison between the two groups.Measurement data with non-normal distribution were expressed as median（interquartile range）[M（Q25,Q75）].Kruskal-Wallis H test was used formaking a comparison among the normal control group,common pneumonia group,and severe pneumonia group,and Mann-Whitney U test was used for comparison between the two groups.Count data were expressed as percentage（%）and analyzed by chi-square test.Multivariate Logistic regression analysis and Receiver operating characteristic（ROC）curve were used to evaluate the value of serum related indicators in the severity of pneumonia and the prognosis of severe pneumonia.The Area Under Curve（AUC）,Youden index,specificity and sensitivity were calculated to evaluate the value of related indicators in the prognosis of severe pneumonia.P<0.05 was considered statistically significant.Results:1.Comparison of general clinical data between groups1.1 Comparison of related markers among normal control group,common pneumonia group and severe pneumonia group:Compared with the normal control group,PCT,CRP,NLR and Lac in the common pneumonia group were higher than those in the normal control group,and the differences were statistically significant（P<0.05）.The TP and ALB in the common pneumonia group were lower than those in the normal control group,and the differences were statistically significant（P<0.05）.Compared with normal control group,PCT,CRP,RDW,NLR and Lac in severe pneumonia group were higher than those in normal control group,and the differences were statistically significant（P<0.05）.T₃,f T₄,f T₃,TP,ALB were lower than those of the normal control group,and the differences were statistically significant（P<0.05）.Compared with the common pneumonia group,the levels of PCT,CRP,RDW and NLR in the severe pneumonia group were higher than those in the common pneumonia group,and the differences were statistically significant（P<0.05）.The levels of T₄,T₃,f T₃,TP and ALB were lower than those of the common pneumonia group,and the differences were statistically significant.1.2 Comparison of related markers between good prognosis group and poor prognosis group:PCT,CRP and RDW in the poor prognosis group were higher than those in the good prognosis group,and the differences were statistically significant（P<0.05）;The levels of T₃,f T₃,TP and ALB in the poor prognosis group were lower than those in the good prognosis group,and the differences were statistically significant（P<0.05）.2.Multivariate Logistic regression analysis between severe pneumonia group and common pneumonia group:PCT and T₃had statistical significance in judging the severity of pneumonia.Both PCT and T₃were independent influencing factors for the severity of pneumonia.The absolute value of standardized coefficient b value（2,443）of T₃was the largest.Among them,PCT was the promoting factor（OR>1）,T₃was the hindering factor（OR<1）.According to the area under the ROC curve（AUC）,PCT combined with T₃（AUC=0.906,95%CI:0.835-0.958.P<0.001）were better than T₃（AUC=0.860,95%CI:0.794-0.26.P<0.001）were better than PCT（AUC=0.811,95%CI:0.725-0.898.P<0.001）.The value of PCT combined with T₃in affecting the severity of pneumonia is greater than that of PCT or T₃alone.3.Multivariate Logistic regression analysis of good prognosis group and poor prognosis group of severe pneumonia:The results showed that PCT and f T₃were independent risk factors for the prognosis of patients with severe pneumonia,and the absolute value of standardized coefficient b value of f T₃（0.627）was the largest.PCT was a risk factor（OR>1）,f T₃was a protective factor（OR<1）.According to the area under the ROC curve（AUC）comparison,PCT,f T₃,PCT combined with f T₃have certain value in affecting the prognosis of severe pneumonia.PCT combined with f T₃（AUC=0.844,95%CI:0.743-0.945.P<0.001）were better than PCT（AUC=0.822,95%CI:0.715-0.929,P<0.001）,better than f T₃（AUC=0.726,95%CI:0.590-0.863,P<0.05）.The value of PCT combined with f T₃in affecting the prognosis of severe pneumonia is greater than that of PCT or f T₃alone.Conclusions:1.T₃level and PCT level can be used to judge the severity of pneumonia patients.2.Combined detection of PCT and T₃levels can improve the judgment value of disease severity in patients with pneumonia.3.Low f T₃level and high PCT level are independent risk factors for poor prognosis of severe pneumonia.4.The combined detection of PCT and f T₃levels can improve the prognostic value of severe pneumonia.