Frequency of Latent Tuberculosis Infection in Patients with Type 2 Diabetes referred to Shahid Rahimi Hospital in Khorramabad City with Tuberculin Skin Test in 2018-2020

Tuberculosis is the leading cause of death from infectious diseases worldwide. Diabetes has been suggested as an important risk factor for tuberculosis. To date, few studies have examined the association between diabetes and tuberculosis. In this study, the prevalence of latent tuberculosis in diabetic patients was investigated.

In this study, 195 patients with type 2 diabetes were studied in a cross-sectional study to diagnose latent tuberculosis infection with a tuberculin skin test. Individuals with symptoms of active tuberculosis were excluded from the study, and individuals with a positive tuberculin test were evaluated for active tuberculosis by chest x-ray. For analyzing the data, SPSS software version 16 was run, a t-test was used to analyze quantitative variables, and for qualitative variables, Chi-square was applied.  The significance level of 0.05 was considered for all the results.

Out of 195 diabetic patients, 115 patients were referred for tuberculin test results. 43 out of 115 patients (37.39%) had an induration diameter greater than or equal to 5 mm, 29 patients (25.21%) had an induration diameter greater than or equal to 8 mm, and 3 patients (2.61%) had an induration diameter greater than or equal to 10 mm (Positive tuberculin test) (p>0.05).

False tuberculin skin test results can hide the true prevalence of latent tuberculosis infection. The sensitivity of the tuberculin test decreases in immunocompromised patients and leads to limitations in assessing the prevalence of latent tuberculosis infection. Although not enough information was available in this study to establish a significant association between diabetes and latent tuberculosis infection, further studies will help to investigate this association.