Diabetes is Associated with Severe Adverse Events in Multidrug-Resistant Tuberculosis

Diabetes mellitus (DM), a very common disease in Mexico, is a well-known risk factor for tuberculosis (TB). However, it is not known by which extent DM predisposes to adverse events (AE) to anti-TB drugs and/or to worse outcomes in patients with multidrug-resistant (MDR-TB) and extensively drug-resistant TB (XDR-TB). The main objective of this study was to describe the outcomes of TB treatment, the impact of DM and the prevalence of AE in a cohort of patients with MDR-/XDR pulmonary TB treated at the national TB referral centre in Mexico City.

Ninety patients were enrolled between 2010 and 2015: 73 with MDR-TB (81.1%), 11 with pre-XDR-TB (12.2%) and 6 (6.7%) with XDR-TB, including 49 (54.4%) with DM, and 3 with Human Immunodeficiency Virus (HIV) co-infection (3.3%). In 98% of patients, diagnosis was made by culture and drug susceptibility testing, while in a single case the diagnosis was made by a molecular test. The presence of DM was associated with an increased risk of serious drug-related AEs, such as nephrotoxicity (Odds Ratio [OR]=6.5; 95% Confidence Interval [95% CI]: 1.9-21.8) and hypothyroidism (OR=8.8; 95% CI: 1.8-54.2), but not for a worse outcome.

Our data suggest that DM does not impact second-line TB treatment outcomes, but patients with DM have a higher risk of developing serious AEs to drug-resistant TB treatment, such as nephrotoxicity and hypothyroidism.