Association between smoking, tuberculosis and diabetes-TB: an analysis on Indian TB patients

Abstract

Background: India is currently carrying the double burden of Communicable diseases like Tuberculosis (TB) and Non communicable diseases (NCDs) like Diabetes Mellitus. Tobacco is one of the established risk factors for NCDs and India has around 28.6% of current tobacco users (GATS-2016-17). Evidence suggests association between tobacco smoking and TB in some populations. We aim to evaluate the association between tobacco smoking and TB and TB-DM both. Methods: The cross sectional study on 400 patients with TB from district Kangra, Himachal Pradesh was carried out in 2014-15. In this analysis the demographic details of TB patients above the age of 18 years were included along with history of tobacco smoking in form of bidi and cigarette. The criteria used for diagnosing type 2-DM was American Diabetes Association criteria or with a diagnosed history of DM and or on oral hypoglycemic drugs/ insulin. The MDR-TB patients and patients suffering from type 1 DM, HIV and leprosy were excluded from the study. Results: At the time of diagnosis of TB 13.5% (54/400) were diagnosed with DM. More than one third (34.4%) of the TB patients without DM were current smokers and 16.5% were ex-smokers at the time of diagnosis. Among the patients suffering from both DM-TB equal proportion were current and ex-smokers (31.4% each). The distribution was statistically significant (p:0.03). The median duartion of bidi/cigarette smoked in years was significantly higher among DM-TB group (20) as compared to TB alone (0.5) (p: 0.03). On multivariate logistic regression analysis only history of current smoker has a significant positive association with TB without DM (OR (95%CI): 2.49 (1.09-7.87). Conclusions: Current smoking was independently associated with TB only. For development of diabetes other factors also play a major role. (Table presented).