Sex differences in the impact of diabetes mellitus on tuberculosis recurrence: a retrospective national cohort study

Whether diabetes mellitus (DM) increases tuberculosis (TB) recurrence risk is debatable. We determined the effect of DM on TB recurrence.This retrospective nationwide cohort study included patients with TB who successfully completed TB treatment during 2011-2017 and were followed up for TB recurrence until August 2020. We performed subdistribution hazard model analyses stratified by sex to assess DM risk related to TB recurrence after successful treatment.Of 199,571 participants who had received successful TB treatment, 47,952 (24%) had DM. There were more men (64.4%), positive acid-fast bacilli smears (35.9%), and positive cultures (49.5%) in the DM group. There were 6208 (3.1%) TB recurrences during 5.1 years of follow-up: 38.9% and 26.6% occurred 1 and 1-2 years after treatment completion, respectively. The recurrence rate was higher in the DM group (3.8%) than in the non-DM group (2.9%, P0.0001). DM was associated with a higher TB recurrence risk, especially in men (adjusted hazard ratio 1.23, 95% confidence interval 1.15-1.32) but not in women (adjusted hazard ratio 0.96, 95% confidence interval 0.85-1.09).The TB recurrence rate after successful treatment was higher in patients with DM than in patients without DM. DM is associated with TB recurrence in men.