Association of thromboangiitis obliterans with cigarette and bidi smoking in Bangladesh: a case-control study

Background In addition to cigarettes, bid, made of unprocessed and low-grad e tobacco, is being smoked widely in Bangladesh and in other south Asian co untries. The cause-and-effect relationship is established between thromboan giitis obliterans (TAO) and smoking. However, type of smoking material(s) m ost strongly related to TAO is not yet determined. Methods We conducted a hospital-based case-control study in Rajshahi, Bangl adesh, to examine the relationship of type of smoking materials (cigarette versus bidi) with TAO on 103 pairs of cases and controls matched by age and sex during the period 1995 to 1996. The inclusion criteria for cases were newly diagnosed TAO and current smoker, while those for controls were curre nt smokers admitted to the hospital due to non-cardiovascular diseases. Results Among the cases 35.0% and 65.0% were cigarette and bidi smokers, wh ile among the controls 69.9% and 30.1%, respectively. Using logistic regres sion approach, considering cigarette smoking similar to 10 per day as refer ence, bid smoking >20 per day (odds ratio [OR] = 34.76, 95% CI: 6.11-197.67 ) and 11-20 per day (OR = 7.12, 95% CI : 2.35-21.63) had greater risk of TA O after adjusting confounding factors. Respective OR for bidi smoking simil ar to 10 per day, cigarette smoking 11-20 per day and cigarette smoking >20 per day, were 2.18 (95% CI:0.64-7.51), 3.81 (95% CI: 1.37-10.57) and 6.88 (95% CI: 1.87-25.30). Conclusions Within the limits inherent to case-control study, our findings suggest that bidi smoking may well play a more important role in causing TA O than cigarettes. It leads to the speculation that unprocessed and low-gra de tobacco used for producing bidi might play a more potent role to initiat e TAO than cigarettes.