Tuberculosis (TB), a prevalent infectious disease worldwide, is primarily caused by Mycobacterium tuberculosis infection. The disease exhibits high infectivity and a wide range of involvement, leading to significant morbidity and mortality.1 According to the Global Tuberculosis Report 2019, there were approximately 10 million new TB cases globally in 2018. China is among the 30 countries with the highest burden of TB patients, with the number of TB cases in the Philippines, Indonesia, China, and India constituting 50 % of the global total. Specifically, China ranks second, accounting for 14 % of the worldwide TB cases.2

Diabetes mellitus (DM), commonly referred to as diabetes, results from either insulin secretion disorders or insulin resistance. The aging population in China contributes to the increasing incidence of diabetes over the years.3 Previous data indicate that the incidence rate of TB in diabetes patients is four times higher than in non-diabetic individuals. When these two diseases coexist, they can exacerbate each other, promoting the progressive development of both conditions. Given the compromised immune function of TB patients, pathogenic bacterial infections are more likely in diabetes patients, potentially leading to complications such as diabetic foot. Conversely, diabetes can impact hormone levels, blood sugar control, and cardiovascular system metabolism, negatively affecting the efficacy of anti-tuberculosis medications.4 Elderly patients often suffer from both diabetes and pulmonary tuberculosis. With declining organ function in the elderly, the presence of these diseases can result in poor health outcomes and treatment efficacy, severely impacting their quality of life and overall health.5

Currently, the intervention strategies for managing diabetes and tuberculosis in elderly patients include the use of hypoglycemic agents and anti-tuberculosis drugs. However, the relapse rate of sputum-positive TB remains high even after anti-tuberculosis treatment.6 This phenomenon has garnered significant attention from experts and scholars both domestically and internationally.7 Therefore, it is crucial to identify the factors contributing to the bacteriological relapse of TB in elderly patients with diabetes to provide targeted interventions during the later stages of treatment and improve treatment success rates. This study aims to explore the factors influencing the relapse of sputum-positive TB in elderly diabetes patients.