Korean J Intern Med.  2018 Sep;33(5):933-940. 10.3904/kjim.2017.249.

The effect of metformin on culture conversion in tuberculosis patients with diabetes mellitus

• Lee YJ
• Han SK
• Park JH
• Lee JK
• Kim DK
• Chung HS
• Heo EY

• KMID: 2420005
• DOI: http://doi.org/10.3904/kjim.2017.249

Abstract

BACKGROUND/AIMS
Patients with diabetes mellitus (DM) and tuberculosis (TB) have increased morbidity and a high risk of treatment failure or recurrence. It is important to manage both diseases simultaneously. Among anti-diabetic drugs, metformin inhibits intracellular growth of mycobacteria. Therefore, we examined the effects of metformin on TB treatment, especially in patients with DM.
METHODS
This retrospective cohort study included patients with culture-positive pulmonary TB diagnosed between 2011 and 2012. The primary study outcome was sputum culture conversion after 2 months of treatment.
RESULTS
Of 499 patients diagnosed with culture-positive pulmonary TB, 105 (21%) had DM at diagnosis. Among them, 62 (59.5%) were treated with metformin. Baseline characteristics, except for the presence of chronic renal disease, were not significantly different between the metformin and non-metformin groups. Metformin treatment had no significant effect on sputum culture conversion (p = 0.60) and recurrence within 1 year after TB treatment completion (p = 0.39). However, metformin improved the sputum culture conversion rate in patients with cavitary pulmonary TB, who have higher bacterial loads (odds ratio, 10.8; 95% confidence interval, 1.22 to 95.63).
CONCLUSIONS
Among cavitary pulmonary TB patients with DM, metformin can be an effective adjunctive anti-TB agent to improve sputum culture conversion after 2 months of treatment.

Keyword

Metformin; Tuberculosis; Diabetes mellitus

MeSH Terms

Bacterial Load
Cohort Studies
Diabetes Mellitus*
Diagnosis
Humans
Metformin*
Recurrence
Renal Insufficiency, Chronic
Retrospective Studies
Sputum
Treatment Failure
Tuberculosis*
Metformin