Objective To explore the correlation and diagnostic value of fractional exhaled nitric oxide (FeNO) and blood eosinophils with lung function in patients with asthma-COPD overlap syndrome (ACOS). Methods A total of 302 patients with obstructive airway disease in Beijing Jishuitan Hospital from April 2020 to April 2025 were selected as the research subjects, including 108 asthma patients, 92 COPD patients, and 102 ACOS patients. Patient data were collected and analyzed. Results There were statistically significant differences in age, smoking history, family history of asthma, FVC, FEV₁, FEV₁/FVC, MVV, FeNO, and blood eosinophil levels among the asthma group, COPD group, and ACOS group (P<0.05). Age and smoking history were positively correlated with the occurrence of ACOS (P<0.05), while family history of asthma, FVC, FEV₁, FEV₁/FVC, MVV, FeNO, and blood eosinophil levels were negatively correlated with the occurrence of ACOS (P<0.05). FeNO and blood eosinophils were not significantly correlated with lung function indicators in ACOS patients (P>0.05). FeNO had good diagnostic value in distinguishing asthma from ACOS (AUC=0.843). FeNO and blood eosinophils both had good diagnostic value in distinguishing COPD from ACOS (AUC=0.848, 0.799). Conclusion FeNO and blood eosinophils are not correlated with lung function indicators in ACOS patients. FeNO, blood eosinophils, and their combination have good diagnostic value in distinguishing asthma from ACOS, and COPD from ACOS, which have the potential to become non-invasive auxiliary diagnostic biomarkers for ACOS.

Objective To investigate the expression characteristics of serum resistin(RETN)and Beclin-1 in patients with gouty arthritis(GA),and to analyze the relationship between RETN and GA clinical charac-teristics and clinical efficacy.Methods A total of 82 GA patients(GA group)and 60 healthy volunteers(con-trol group)in Dongguan People's Hospital from January 2019 to December 2022 were enrolled in the study.The expressions of serum RETN and Beclin-1 in GA patients were detected before and after treatment(on the physical examination day of the control group),and the differences of serum RETN and Beclin-1 in GA pa-tients with different clinical characteristics and efficacy were compared.Pearson correlation analysis was used to investigate the correlation between serum RETN,Beclin-1 expression and uric acid(UA)level in GA pa-tients.The diagnostic value of serum RETN and Beclin-1 in GA was analyzed using the receiver operating characteristic(ROC)curve.Results The serum RETN level in the GA group was higher than that in the con-trol group,and the expression of Beclin-1 was lower than that in the control group(P<0.05).The serum RETN levels in GA patients with acute stage,disease duration≥5 years,affected joints≥5,annual attack fre-quency≥3 times were higher than those in GA patients with chronic stage and intermittent stage,disease du-ration<5 years,affected joints<5,annual attack frequency<3 times(P<0.05),and the expression of Bec-lin-1 were lower than those in GA patients in chronic and intermittent stages,disease duration<5 years,af-fected joints<5,annual frequency<3 times(P<0.05).The serum UA level in GA patients was positively correlated with RETN(r=0.674,P<0.05),and negatively correlated with Beclin-1 expression(r=-0.568,P<0.05).After treatment,the serum expression of level RETN in the effective group was lower than that in the ineffective group,while the level Beclin-1 was higher than that in the ineffective group(P<0.05).The ar-ea under the curve of combined RETN and Beclin-1 diagnosis for GA was 0.921,which was higher than that of individual diagnosis(Z=3.752,3.154,P<0.05).Conclusion Serum RETN level increases,and Beclin-1 ex-pression decreases in GA patients,which is associated with increased UA level,prolonged acute stage and course of GA,increased number of affected joints and annual attack frequency,and treatment ineffectiveness.RETN and Beclin-1 could serve as biomarkers for GA diagnosis.