title: Association of smoked and smokeless tobacco use with migraine: a hospital-based case-control study in Dhaka, Bangladesh.
abstract: BACKGROUND
  Several studies in the past have reported inconclusive evidences on association of smoking and migraine. Nevertheless, no study so far reported association of smokeless tobacco with migraine. The objective of this study was to examine the association of smoked and smokeless tobacco use with migraine.
  
  
  METHODS
  A hospital-based case-control study was conducted at the neurology outpatient department of a tertiary care hospital in Dhaka, Bangladesh. We enrolled 138 migraine cases diagnosed during March-September 2010 in neurology outpatient department, and 276 gender and age matched healthy controls from among their attendants. Diagnosis of migraine was based on the International Headache Society criteria. Use of smokeless tobacco and smoking (cigarette/bidi/hukka) were determined by an interviewer administered questionnaire.
  
  
  RESULTS
  Among the cases, 52.9% were overall tobacco users; 24.6% were only smokers, 15.9% only smokeless tobacco users and 12.3% used both. The respective figures among controls were 14.5%, 7.2%, 6.9% and 0.4% (P <0.001 for all). The conditional logistic regression analysis found that migraine had higher odds of exposure to smoked tobacco use, smokeless tobacco use, and both compared to control after adjusting for confounding variables (alcohol drinking, insufficient sleep, mental stress, and number of family members); adjusted odds ratio (aOR) was 6.6 (95% confidence interval [CI] = 2.2-19.6, P = 0.001), 5.8 (95%CI = 1.9-17.4, P = 0.001), and 54.2 (95%CI = 4.3-684.4, P = 0.002), respectively. The aOR of cigarette/bidi/hukka smoking for different doses was 5.5 (95%CI = 1.2-24.8, P = 0.027) for 1-5 times per day, 6.3 (95%CI = 1.8-21.2, P = 0.003) for 6-10 times per day, and 6.7 (95%CI = 1.9-23.2, P = 0.003) for >10 times per day relative to non users.
  
  
  CONCLUSIONS
  Both smoked and smokeless tobaccos were found to be associated with migraine. There is a need to incorporate smokeless tobacco along with smoked tobacco into the anti-tobacco awareness programs to reduce the burden of migraine in Bangladesh.
authors.affiliation: Young Leaders' Program in Healthcare Administration, Nagoya University Graduate School of Medicine, Nagoya, Japan. basarcmc@yahoo.com.
authors.forename: Mohammad Abul Bashar
authors.initials: MA
authors.lastname: Sarker
authors.forename: Mahbubur
authors.initials: M
authors.lastname: Rahman
authors.forename: Md
authors.initials: M
authors.lastname: Harun-Or-Rashid
authors.forename: Shaila
authors.initials: S
authors.lastname: Hossain
authors.forename: Hideki
authors.initials: H
authors.lastname: Kasuya
authors.forename: Junichi
authors.initials: J
authors.lastname: Sakamoto
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamajima