Tuberculosis-diabetes epidemiology in the border and non-border regions of Tamaulipas, Mexico

Type 2 diabetes mellitus (DM) is a re-emerging risk factor for TB development and adverse TB outcomes. As a follow-up of our previous study in 1998-2004, we reassessed prevalence of DM and its associated factors among 8431 TB patients using surveillance data from 2006 to 2013 for the Mexican state of Tamaulipas, across the border with Texas. Prevalence of DM was 25.2%, with an increase of at least 2.8% over the study period. Newly discovered factors associated with TB-DM (versus no DM) were lower education and higher unemployment (p < 0.001), which are reportedly associated with poorer DM management. At least 15% of the DM patients were newly-diagnosed and younger than those previously diagnosed, showing the importance of early DM diagnosis at TB clinics. TB-DM patients were more likely to have smear-positive, pulmonary (versus extra-pulmonary) and drug-resistant TB (1.9-, 3.8- and 1.4-fold, respectively). During treatment, TB-DM patients were more likely to be smear-positive, and less likely to die or abandon TB treatment. Thus, the increasing prevalence of DM among TB, and its association with low education, features of a more contagious TB, and drug resistance, highlight the need for design of TB management programs in DM patients, blood testing of all new TB patients for DM, and if positive for DM, testing for drug resistance.