Co-Infection of Tuberculosis and Diabetes

A cross-sectional study conducted at Ad-din Barrister Rafique-ul Huq Hospital in Dhaka between January and December 2023 explored the clinical profile, treatment adherence, and factors influencing poor treatment outcomes among elderly patients with coexisting tuberculosis (TB) and diabetes mellitus (DM). The study included 130 patients over the age of 60, with a majority being male (64.6%) and within the 60–64 age range (32.3%). Among the participants, 37.7% were underweight and 58.5% had a history of smoking—both known risk factors for TB and DM complications. Pulmonary TB was more prevalent (75.4%) than extrapulmonary TB (24.6%), and a significant proportion (64.6%) had uncontrolled diabetes (HbA1c ≥7.0). Additionally, 20.8% were diagnosed with multidrug-resistant TB (MDR-TB), further complicating treatment. Comorbid conditions such as hypertension (54.6%), cardiovascular disease (32.3%), and chronic kidney disease (30.0%) were also commonly observed.[2]

Regarding treatment, 79.2% of patients received standard anti-tubercular therapy, while 20.8% required MDR-specific regimens. Diabetes was managed using metformin in 47.7% of cases and insulin in 31.5%. Encouragingly, 70.8% of the patients demonstrated good adherence to treatment. However, several factors were significantly associated with unfavorable treatment outcomes, including advanced age, hypertension, poor treatment adherence, uncontrolled diabetes (adjusted odds ratio [AOR]: 4.12, p<0.001), and MDR-TB (AOR: 5.01, p<0.001). The study highlights the complex health challenges faced by elderly TB-DM patients in Dhaka and underscores the urgent need for integrated care strategies to address the dual burden of TB and diabetes, particularly focusing on managing glycemic control and drug resistance.[2]

A study aimed to assess the effect of prediabetes on tuberculosis (TB) treatment outcomes. Patients were divided into two groups: those with normoglycemia (Group I) and those with prediabetes (Group II). Significant demographic differences were observed between the groups. Group II patients were older, had lower literacy rates, and a higher proportion of unskilled workers. However, other factors such as gender distribution, income, BMI, smoking, alcohol use, and family history of TB were similar across both groups. A notable difference was the higher prevalence of a positive family history of diabetes in Group I.[1]

Biochemically, fasting and postprandial glucose levels were elevated in Group II, with HbA1c levels being significantly higher (6.0 ± 0.21 vs. 5.3 ± 0.23, p < 0.0001). Other parameters, including urea, creatinine, total cholesterol, and hemoglobin levels, showed no significant variation. Despite these metabolic differences, TB treatment outcomes were largely similar. The overall cure rate was 72.7%, with no significant difference between groups (p = 0.38). Treatment failure and defaulter rates were also comparable. While a higher proportion of deaths occurred in the prediabetes group (6.3% vs. 1.3%), the difference was not statistically significant (p = 0.09). Similarly, relapse rates were slightly higher in Group II but did not reach significance.[1]

One critical finding was the delay in sputum conversion among TB patients with prediabetes. The average number of days taken for sputum conversion was significantly higher in Group II (62.4 ± 3.8 vs. 64.2 ± 4.7, p = 0.03). At the end of the intensive treatment phase, a significantly larger proportion of patients in Group II remained sputum smear-positive (23.8% vs. 8.6%, p = 0.019), with an estimated relative risk of 3.0 (95% CI: 1.2–7.6). Baseline chest X-ray scores were higher in Group II, indicating more severe lung involvement, but the difference was not statistically significant. Both groups showed improvement in X-ray scores after treatment, with no significant difference in the degree of reduction.[1]

A key result from the logistic regression analysis was the strong association between HbA1c levels at enrollment and unfavorable TB treatment outcomes. Patients with higher HbA1c were nearly four times more likely to experience poor outcomes (OR = 3.98, p = 0.007). Although male gender showed a trend towards significance as a risk factor, it did not reach statistical significance.[1]

In conclusion, while prediabetes did not significantly impact overall TB treatment success rates, it was associated with delayed sputum conversion and a higher likelihood of remaining smear-positive at the end of the intensive treatment phase. This finding suggests that glycemic control plays a crucial role in TB prognosis. Given that HbA1c emerged as a significant predictor of poor TB outcomes, screening and early intervention for prediabetes in TB patients could improve treatment response. Further research is needed to determine whether targeted glycemic control strategies can enhance TB treatment outcomes in prediabetic individuals.[1]

Source:

1. Viswanathan, V., Devarajan, A., Kumpatla, S., Dhanasekaran, M., Babu, S. and Kornfeld, H., 2023. Effect of prediabetes on tuberculosis treatment outcomes: A study from South India. Diabetes & Metabolic Syndrome: Clinical Research & Reviews, 17(7), p.102801.

2. Rima, U.S., Islam, J., Mim, S.I., Roy, A., Dutta, T., Dutta, B. and Ferdaus, F.F., 2024. Co-Infection of Tuberculosis and Diabetes: Implications for Treatment and Management. Asia Pacific Journal of Surgical Advances, 1(2), pp.51-58.