title: Body mass index, tobacco chewing, alcohol drinking and the risk of oral submucous fibrosis in Kerala, India.
abstract: OBJECTIVE
  While chewing areca nut is considered a risk factor for oral submucous fibrosis, the effects of cigarette smoking, alcohol drinking, and body mass index (BMI) have not been examined; nor are they well established. In this study we investigated the association between BMI, smoking, drinking, and the risk of oral submucous fibrosis.
  
  
  METHODS
  We conducted a case-control study within the framework of an ongoing randomized oral cancer screening trial in Kerala, India. Trained health workers conducted interviews with structured questionnaires and oral visual inspections to diagnose oral premalignant lesions. A total of 170 oral submucous fibrosis cases (139 women and 31 men) and 47,773 controls were identified. The odds ratios (OR) and 95% confidence intervals (CI) were calculated by logistic regression in SAS.
  
  
  RESULTS
  The adjusted OR for ever-tobacco chewing was 44.1 (95% CI = 22.0-88.2). An inverse dose-response relationship was seen between BMI and the risk of oral submucous fibrosis when both genders were combined (p for trend = 0.0010), with an OR of 0.5 (95% CI = 0.3-0.9) for the highest BMI quartile compared to the lowest. Alcohol drinking may possibly be associated with the risk of oral submucous fibrosis; the adjusted OR for ever drinking was 2.1 (95% CI = 1.0-4.4). Cigarette smoking did not appear to be a risk factor for women or for men. Both smoking and drinking were rare habits among women.
  
  
  CONCLUSIONS
  This study suggested, for the first time, that BMI was inversely associated with the risk of oral submucous fibrosis for both genders when potential confounding factors were adjusted. Our results indicated that alcohol drinking might be a moderate risk factor and confirmed the previous observation that chewing tobacco was a strong risk factor for oral submucous fibrosis.
authors.affiliation: Department of Epidemiology, UCLA School of Public Health and Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095-1772, USA.
authors.forename: Mia
authors.initials: M
authors.lastname: Hashibe
authors.forename: Rengaswamy
authors.initials: R
authors.lastname: Sankaranarayanan
authors.forename: Gigi
authors.initials: G
authors.lastname: Thomas
authors.forename: Binu
authors.initials: B
authors.lastname: Kuruvilla
authors.forename: Babu
authors.initials: B
authors.lastname: Mathew
authors.forename: Thara
authors.initials: T
authors.lastname: Somanathan
authors.forename: Donald Maxwell
authors.initials: DM
authors.lastname: Parkin
authors.forename: Zuo-Feng
authors.initials: ZF
authors.lastname: Zhang
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects*; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005355:Fibrosis / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009059:Mouth Diseases / Q000453:epidemiology* / Q000473:pathology*; D009061:Mouth Mucosa / Q000473:pathology; D016017:Odds Ratio; D012016:Reference Values; D012307:Risk Factors; D017678:Sex Distribution; D014030:Tobacco, Smokeless / Q000009:adverse effects*