DM among patients with TB in South Korea

In a comprehensive study across South Korea, 1,407 patients diagnosed with culture-proven multidrug-resistant tuberculosis (MDR-TB) were meticulously tracked. These patients were enrolled from various healthcare settings, including 360 from national TB hospitals, 836 from Korean National Tuberculosis Association (KNTA) chest clinics, and 211 from eight university hospitals near Seoul. The medical records of these patients were reviewed in detail, capturing demographics, past TB treatment, existing comorbidities, and extensive diagnostic results like AFB cultures and drug susceptibility tests, alongside treatment outcomes.[1]

A notable finding was that 17% of these patients, or 239 individuals, also suffered from diabetes, defined by their prior diagnosis and current medication use for diabetes at the time of their MDR-TB diagnosis. This subgroup, termed the MDR-TBDM(+) group, not only had a higher average age and BMI but also experienced a significantly lower treatment success rate of only 36.0%, compared to 47.2% in those without diabetes (MDR-TBDM(–)).[1]

Statistical analysis confirmed diabetes as an independent and negative predictor for successful TB treatment, with an odds ratio indicating a 49% decrease in the likelihood of treatment success for diabetic patients. Additionally, low BMI and the presence of extensively drug-resistant TB (XDR-TB) were also significant factors negatively impacting treatment outcomes.[1]

Following these patients for 8-11 years post-treatment initiation revealed that the combination of TB with diabetes markedly increased the risk of treatment failure and mortality. Consequently, diabetic patients with MDR-TB faced not only lower treatment success but also a reduced survival rate compared to their counterparts without diabetes.[1]

To explore the complex relationship between tuberculosis (TB) and diabetes, researchers in South Korea established the Korean Tuberculosis and Post-Tuberculosis cohort (TB-POST). This detailed cohort was created by integrating data from multiple sources: the Korean National Tuberculosis Surveillance System (KNTSS), the National Health Information Database (NHID), and vital statistics from Statistics Korea. The main objective was to analyze how diabetes affects treatment outcomes and other health indicators for TB patients over the period from 2011 to 2018.[2]

The findings from this cohort indicated that diabetes was prevalent among TB patients, with a rate of 26.8%. A significant subset, approximately 12.5%, developed diabetes following their TB diagnosis, termed new-onset diabetes (nDM). The prevalence of diabetes in TB patients was observed to rise with age, reaching a high of 42.1% in men aged 65-74. Gender differences were evident, with men more likely to suffer from both conditions simultaneously. Additionally, age-standardized data showed an increase in co-prevalence with age, and lower income was identified as a contributing factor to diabetes among TB patients. Patients diagnosed with TB who later developed new-onset diabetes were generally younger and more likely to have a positive AFB smear. This suggests they might have been at an advanced stage of TB at diagnosis, possibly due to undiagnosed diabetes.[2]

References: 

[1] Kang, Y.A., Kim, S.Y., Jo, K.W., Kim, H.J., Park, S.K., Kim, T.H., Kim, E.K., Lee, K.M., Lee, S.S., Park, J.S. and Koh, W.J., 2014. Impact of diabetes on treatment outcomes and long-term survival in multidrug-resistant tuberculosis. Respiration, 86(6), pp.472-478.

[2] Jeong D, et al. Prevalence and associated factors of diabetes mellitus among patients with tuberculosis in South Korea from 2011 to 2018: a nationwide cohort study. BMJ Open 2023;13:e069642. https://bmjopen.bmj.com/content/13/3/e069642