The impact of diabetes mellitus and its control on the development of tuberculosis: A nationwide longitudinal study in Taiwan

Purpose Diabetic mellitus (DM) is a well-known risk factor of tuberculosis (TB). However, there is paucity of reports on the impact of diabetic control and adherence to anti-diabetic treatment on the risk of TB. This nationwide cohort study aimed to address these issues. Methods In the Longitudinal Health Insurance Database 2005 of Taiwan, DM cases and matched control subjects were selected. Potential risk factors for developing TB were investigated using the Cox proportional hazards regression analysis. Time-dependent variables were used to measure drug prescription, adherence, and number of DM-associated admissions from 360 to 90days prior to each outcome event. Results The 49903 DM patients identified (52.5% males) had a mean age of 61.9±14.2years. Among DM patients and control subjects, the independent risk factors of TB were age, male sex, chronic obstructive pulmonary disease (COPD), autoimmune disease, and DM (hazard ratio [HR] 1.293 [1.154–1.449]). Among DM patients, time-dependent Cox analysis revealed that age, male sex, COPD, endstage renal disease, maximum average daily dose of oral hypoglycemic agent (HR 1.13 [1.071–1.193]), insulin use during admission (HR 1.462 [1.087–1.966]), adherence to anti-diabetic medication (0.577 [0.429–0.776]), and number of DM-associated admissions (1.789 [1.231–2.601]) were independent factors associated with the development of TB. Conclusions The risk of TB parallels DM severity. Some cases of TB can be prevented by fostering adherence to anti-diabetic medication. Copyright © 2013 John Wiley & Sons, Ltd. key words—adherence; cohort study; diabetes mellitus; National Health Insurance Database; tuberculosis; pharmacoepidemiology