High prevalence of resistance to first-line drugs and multidrug resistance in patients with tuberculosis and type 2 diabetes mellitus at a referral hospital in Peru

INTRODUCTION: The coexistence of tuberculosis (TB) and type 2 diabetes mellitus (T2DM) poses an emerging public health challenge, especially in high-TB-burden settings such as Peru. This comorbidity has been associated to unfavorable clinical outcomes and a higher frequency of drug-resistant TB. OBJECTIVE: To estimate the prevalence of resistance to first-line antituberculosis drugs and identify factors associated with multidrug resistance tuberculosis (MDR-TB) among patients with T2DM and pulmonary TB treated at a public hospital in Lima, Peru. METHODS: A cross-sectional study was conducted using secondary data from 130 adults with T2DM and microbiologically confirmed pulmonary TB treated at a Peruvian hospital between 2015 and 2019. Drug susceptibility results were categorized as susceptible, monoresistant, polyresistant, or MDR-TB. Factors associated with MDR and resistance to at least one first-line drug were evaluated using Poisson regression models with robust variance. RESULTS: The prevalence of resistance to at least one first-line drug was 34.6%, and the prevalence of MDR-TB was 21.5%. The most frequent resistances were to isoniazid (28.4%) and rifampicin (26.2%). In the multivariable analysis, age 40-49 years (aPR = 2.99; 95% CI: 1.00-8.97) and age 70-85 years (aPR = 4.13; 95% CI: 1.16-14.7) and were independently associated with MDR-TB. Furthermore, a diabetes duration of at least 5 years was associated with resistance to at least one drug (aPR ≈ 2.1). CONCLUSION: A high prevalence of drug resistance, including MDR-TB was observed among patients with T2DM and pulmonary TB. Older age and longer duration of diabetes were associated with bacterial resistance in the adjusted analysis. These findings underscore the importance of considering diabetes-related clinical characteristics when evaluating drug resistance patterns in patients with tuberculosis.