Effect of type II diabetes mellitus on treatment outcomes of tuberculosis

CONTEXT: There is conflicting evidence of effect of diabetes on treatment of tuberculosis (TB). There is a need to investigate effect of diabetes on outcomes of TB treatment under field conditions in India. AIMS: To compare treatment outcomes among TB patients with diabetes with those without diabetes. SETTING AND DESIGN: Study was conducted in Cuddalore, Tamil Nadu, among patients registered with Revised National TB Control Programme. Prospective observational study design was used. MATERIALS AND METHODS: Registered TB patients aged 30 and above were invited to participate in the study. Those who were not aware of their diabetic status were diagnosed using oral glucose tolerance test. A total of 89 diabetic and 120 non-diabetic patients were recruited in the study. They were followed up till the end of treatment and outcomes were recorded. STATISTICAL ANALYSIS USED: Treatment outcomes in the two groups were compared using bi-variate and multi-variate analysis. RESULTS: Bi-variate (unadjusted) analysis showed similar treatment success rates in the two groups. But, the adjusted odds ratios for successful treatment among diabetic patients were significantly lower (0.191, 95% CI 0.04-0.90) for pulmonary TB patients and for smear positive pulmonary TB patients (odds ration 0.099, 0.013-0.761). Diabetes was found to be predictor for sputum positivity at end of treatment. CONCLUSIONS: Diabetes increases risk of poor treatment outcomes among pulmonary TB patients. The study highlights need of screening of TB patients for diabetes. There is need to see the effect of glycemic control on treatment outcomes among diabetics.