The relationship between fasting blood glucose level and sputum smear,T-SPOT.TB results in patients with T2DM complicated with tuberculosis,and the clinical significance of detecting the rpoB gene of Mycobacterium tuberculosis

YU Yanting; ZHONG Lei; WAN Rong; ZHANG Huajie; HUANG Rui; ZHANG Lin

doi:10.3969/j.issn.1007-8134.2024.02.006

Abstract：Objective To explore the relationship between fasting plasma glucose(FPG)levels and sputum smear results,T-cell spot test for tuberculosis infection(T-SPOT.TB)in patients with pulmonary tuberculosis and type 2 diabetes mellitus(T2DM),as well as the clinical significance of rpoB gene detection in Mycobacterium tuberculosis.Methods A total of 102 patients by pulmonary tuberculosis,who were admitted to the Kunming Third People's Hospital from January 2022 to January 2023,were selected as the study group.Another 102 patients with only pulmonary tuberculosis treated in our hospital during the same period were selected as the control group.And compare the clinical data,sputum smears,and T-SPOT test results between the 2 groups.Analyze the correlation between the positive rates of sputum smears and T-SPOT.TB tests with different fasting plasma glucose(FPG)levels in the study group.Furthermore,culture Mycobacterium tuberculosis from both groups,isolate rifampicin-resistant and sensitive strains,and compare the rpoB gene detection results between these strains in the 2 groups.Results The incidence of cough,dyspnea,anorexia,night sweating,chest pain,hemoptysis,fever,sputum smear positive rate,and T-SPOT.TB positive rate in the study group were higher than those in the control group(P＜0.05).Comparison of sputum smear positive rates among patients with different FPG levels showed statistically significant differences(P=0.003),while the comparison of T-SPOT.TB positive rates showed no statistically significant difference(P=0.262).The positive rate of sputum smear is positively correlated with the FPG level in patients with T2DM complicated with pulmonary tuberculosis(rs=0.386,P=0.015),while the positive rate of T-SPOT.TB was not significantly correlated with FPG levels(rs=0.127,P=0.326).The research group had more RFP-resistant strains than the control group,and the mutation rate of rpoB gene in RFP-resistant strains was higher than that in RFP-sensitive strains(P＜0.05).Conclusion The FPG levels in patients with T2DM and pulmonary tuberculosis are closely related to the results of sputum smears,but there is no significant correlation with T-SPOT.TB results.In addition,the detection of the drug-resistance gene rpoB can quickly identify and detect resistance of Mycobacterium tuberculosis to RFP,providing scientific guidance for clinical treatment.