The impact of diabetes and pre diabetes on the sputum smear conversion in tuberculosis: Retrospective cohort study at the National Hospital of Respiratory Diseases, Sri Lanka

Abstract

Objective: To assess the impact of diabetes and pre diabetes on the sputum smear conversion among patients with tuberculosis Methods: Retrospective analysis performed using the clinical records of the district tuberculosis clinic, Gampaha district, Sri Lanka from September to October 2016. Patients with extra pulmonary TB were excluded. Results: 336 out of 428(78.5%) were analyzed. 231 were undergone sputum smear examinations at second month of treatment. Median age 50(18 to 78) years. Males 159(68.8 %%). Smear positive pulmonary TB 172 (74.5%), smear negative pulmonary TB 44(19%), relapsed previously 7(3%) and previously defaulted 8(3.5%). 20(8.7%) had pre diabetes, and 82(35.5%) had diabetes. 41(17.7%) had sputum smear positivity at the second month of treatment and 190(82.3%) had negative smears. 18 (22%) of diabetes patients failed to convert at two months compared to 23(15.4%) at nondiabetic group. Altogether 24(23.5%) patients with diabetes or pre diabetes were failed to convert at the second month of therapy. There is a statistically significant risk of sputum non conversion among patients with diabetes or pre diabetes (odds 2.0(1.0 to 4.0) p = 0.04). Conclusion: Patients with diabetes or pre diabetes had a significant risk of sputum non conversion at the second month of anti tuberculosis therapy.