Abstract:

Objective: To analyze the phenotypic drug resistance spectrum of adult patients with active pulmonary tuberculosis (PTB) complicated with diabetes mellitus in Nanjing, and to provide evidence for the prevention and control of tuberculosis. Methods: A retrospective study was conducted. The clinical isolates and data of 2089 adult PTB patients with culture positive were collected from the Second Hospital of Nanjing from 2019 to 2021. The patients were divided into PTB patients complicated with diabetes mellitus (comorbidity group; 544 cases) and non-diabetic PTB patients (non-comorbidity group; 1545 cases). After 1∶2 case matching by age, sex, body mass index (BMI), and history of anti-tuberculosis treatment, a total of 541 cases in the comorbidity group and 881 cases in the non-comorbidity group were included. The drug resistance spectrum of the two groups were analyzed, as well as the drug resistance spectrum and ranking of drug resistance in the comorbidity group with different levels of blood glucose. Results: The drug resistance rates of levofloxacin (13.1% (71/541)), rifampicin-susceptible and isoniazid-resistant tuberculosis (hr-TB, 10.5% (57/541)), and pre-extensive drug-resistant tuberculosis (pre-XDR-TB, 6.8% (37/541)) in the comorbidity group were higher than those in the non-comorbidity group (8.9% (78/881), 7.5% (66/881), and 4.1% (36/881)), and the differences were statistically significant (χ²=6.516, P=0.011; χ²=3.932, P=0.047; χ²=5.216, P=0.022). The resistance rate of hr-TB in the newly diagnosed comorbidity group (9.4% (41/436)) was higher than that in the non-comorbidity group (6.3% (45/717)), and the resistance rates of levofloxacin and pre-XDR-TB in the comorbidity group for retreatment cases (38.1% (40/105) and 25.7% (27/105)) were higher than those in the non-comorbidity group (22.6% (37/164) and 14.0% (23/164)), and the differences were statistically significant (χ²=3.842, P=0.049; χ²=7.561, P=0.006; χ²=5.781, P=0.016). The rates of isoniazid mono-resistance (12.8% (24/187)) and hr-TB (12.8% (24/187)) were higher in patients with uncontrolled fasting blood glucose than in those with controlled fasting blood glucose (6.4% (16/249) and 6.8% (17/249)) in the newly diagnosed comorbidity group, the differences were statistically significant (χ²=5.264, P=0.022; χ²=4.523, P=0.033). The drug resistance ranking in both the newly diagnosed and retreatment cases in the comorbidity group was isoniazid (15.1% (66/436) and 44.8% (47/105))>levofloxacin (7.1% (31/436) and 38.1% (40/105))>rifampicin (6.4% (28/436) and 36.2% (38/105))>ethambutol (2.1% (9/436) and 16.2% (17/105)). The drug resistance rate of hr-TB (9.4% (41/436)) in the newly diagnosed comorbidity group was higher than that of multidrug-resistant tuberculosis (MDR-TB)(5.7% (25/436)), and the difference was statistically significant (χ²=4.196, P=0.041). Conclusion: The rate of isoniazid-related resistance in adults with active PTB together with diabetes in Nanjing is increasing, especially in patients with newly diagnosed tuberculosis, and it is necessary to initiate isoniazid-resistance screening in patients with newly treated PTB complicated with diabetes mellitus and poor fasting blood glucose control as soon as possible.

Key words: Tuberculosis, pulmonary, Diabetes mellitus, Tuberculosis, multidrug-resistant, Population surveillance