Addressing the Dual Burden of Type 2 DM and Pulmonary Tuberculosis

Patients with Type 2 Diabetes Mellitus (T2DM) and Pulmonary Tuberculosis (PTB) are at a higher risk of poor glycemic control, frequent infections, and unhealthy lifestyle behaviors such as smoking, alcohol use, and physical inactivity. Risk factors for having both conditions include lymphopenia, smoking, history of TB exposure, and poor glycemic control, while being overweight or obese appears to lower the risk of concurrent PTB in T2DM patients.

Diabetes is a recognized risk factor for tuberculosis (TB), and its role is emphasized in the global post-2015 TB strategy. However, collaboration between TB and diabetes programs is inadequate in most countries. Thirteen countries, including Afghanistan, China, India, and Indonesia, account for 60% of new TB cases worldwide. Stabilizing diabetes prevalence in these countries could reduce TB incidence by over 20% and mortality by nearly 43% by 2035, potentially preventing over 1 million TB deaths. However, the impact depends on factors like relapse rates and the effect of rising BMI, which can counteract diabetes' negative effects on TB.

The need for integration between communicable and non-communicable disease sectors is clear. Proposed strategies include bidirectional screening for diabetes and TB and adapting treatment frameworks like DOTS for non-communicable diseases in resource-limited areas.

On the diagnostic front, laboratories are better prepared to test resistance to established drugs like fluoroquinolones and linezolid than to newer drugs like bedaquiline, essential for multidrug-resistant TB (MDR-TB). Phenotypic drug susceptibility tests (pDSTs), requiring biosafety level 3 labs, are time-consuming but effective, though faster molecular tests like Xpert MTB/RIF and line probe assays (LPAs) are becoming more common. Whole-genome sequencing (WGS) is also being explored for its comprehensive resistance profiling, though it remains expensive and labor-intensive.

New methods like the Thin-Layer Agar method and QuantaMatrix Multiplexed Assay Platform show promise for drug resistance detection in low-resource settings. Advanced sequencing technologies such as the MinION platform offer cost-effective solutions, and emerging tools like MALDI-TOF are competing with WGS in the diagnostic space.

The rising prevalence of diabetes, particularly in middle- and low-income countries, poses a major challenge to TB control efforts. This trend is compounded by smoking, which remains a significant risk factor for TB, especially in countries like Pakistan. With over 80% of global TB cases concentrated in 30 countries, focused interventions are essential. England, with its low TB incidence, still faces disparities, particularly among foreign-born individuals and those with social risk factors like homelessness or substance abuse.

Preventing diabetes could significantly impact TB incidence and mortality, and coordinated public health strategies that address both diseases are urgently needed to achieve long-term control.

Sources:

1. Shi H, Yuan Y, Li X, Li YF, Fan L, Yang XM. Analysis of the influencing factors and clinical related characteristics of pulmonary tuberculosis in patients with type 2 diabetes mellitus. World J Diabetes 2024; 15(2): 196-208.
2. Pan, S.C., Ku, C.C., Kao, D., Ezzati, M., Fang, C.T. and Lin, H.H., 2015. Effect of diabetes on tuberculosis control in 13 countries with high tuberculosis: a modelling study. The lancet Diabetes & endocrinology, 3(5), pp.323-330. https://tbreadingnotes.blogspot.com/2024/07/effect-of-diabetes-on-tuberculosis.html
3. Sanchini, A., Lanni, A., Giannoni, F. and Mustazzolu, A., 2024. Exploring Diagnostic Methods for Drug-Resistant Tuberculosis: A Comprehensive Overview. Tuberculosis, p.102522. https://tbreadingnotes.blogspot.com/2024/09/exploring-diagnostic-methods-for-drug.html
4. Khalid N, Ahmad F, Qureshi FM. Association amid the comorbidity of Diabetes Mellitus in patients of Active Tuberculosis in Pakistan: A matched case control study. Pak J Med Sci. 2021;37(3):816-820.
5. Meghji, J., Kon, O.M. and Ainley, A., 2023. Clinical tuberculosis. Medicine, 51(11), pp.768-773. https://tbreadingnotes.blogspot.com/2024/08/clinical-tuberculosis.html

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