Impact of Diabetes Mellitus on Treatment Outcomes of Tuberculosis Patients in Tertiary Care Setup

Background: Concurrent diabetes mellitus (DM) with tuberculosis (TB) has an increased risk of treatment failure. This study was aimed to evaluate treatment outcomes in patients with TB with and without DM. Methods: A retrospective cohort study was conducted at respiratory clinic of Hospital Pulau Pinang, Malaysia. All TB-registered patients from January 2006 to December 2007 were included in the study. A validated data collection form was used for collecting data. World Health Organization's criterion was used for categorizing treatment outcomes. Data were analyzed by using SPSS 16. Results: Of 1267 patients, 338 patients (26.7%) had concurrent TB-DM. In multivariate analysis, TB-DM was more likely to be present in Chinese (odds ratio [OR] = 1.401, P = 0.011), patients having age of 46 to 60 years (OR = 3.168, P < 0.001) and >60 years (OR = 2.524, P < 0.001) and patients with pulmonary TB (OR = 2.079, P < 0.001). Nine hundred and eighty-five (78.8%) patients were successfully treated. No statistically significant difference was observed between 2 groups: patients with TB-DM and patients with only TB. Successful treatment outcomes were observed in patients having age of 46 to 60 (OR = 1.567, P = 0.001), whereas male gender (OR = 0.721, P = 0.049) and patients with relapse TB (OR = 0.494, P = 0.002) were less likely to have successful treatment outcome. Conclusions: High prevalence of TB-DM in the study signifies the fact that patients with DM are at high risk of developing TB. Treatment outcomes in both groups were comparable. The gender-based and age-based disparity in TB treatment outcomes in this study indicates the importance of gender-specific and age-specific strategies of TB management.