title: Lifestyle related risk factors in the aetiology of gastro-oesophageal reflux.
abstract: OBJECTIVE
  The aetiology of gastro-oesophageal reflux is largely unknown. The authors' aim was to examine the relation between lifestyle habits and gastro-oesophageal reflux symptoms.
  
  
  METHODS
  Participants of two consecutive public health surveys in Nord-Trondelag, Norway.
  
  
  METHODS
  In a case control study within the two public health surveys, 3153 individuals who in the second survey reported severe heartburn or regurgitation during the last 12 months were defined as cases, while 40 210 people without reflux symptoms constituted the control group. The risk of reflux symptoms was estimated and multivariately calculated as odds ratios in relation to exposure to tobacco smoking, alcohol, coffee, tea, table salt, cereal fibres, and physical exercise.
  
  
  RESULTS
  There was a significant dose response association between tobacco smoking and reflux symptoms. Among people who had smoked daily for more than 20 years the odds ratio was 1.7 (95% confidence interval 1.5 to 1.9) compared with non-smokers. A similar positive association was found for table salt intake. The odds ratio for reflux was 1.7 (95% CI 1.4 to 2.0) among those who always used extra table salt compared with those who never did so. We found moderately strong negative associations between the risk of reflux and exposure to coffee, bread high in dietary fibre content, and frequent physical exercise. Intake of alcohol or tea did not affect the risk of reflux.
  
  
  CONCLUSIONS
  Tobacco smoking and table salt intake seem to be risk factors for gastro-oesophageal reflux symptoms. Dietary fibres and physical exercise may protect against reflux. Alcohol, coffee, and tea do not seem to be risk factors for reflux.
authors.affiliation: Department of Surgery, Karolinska Hospital, SE-171 76 Stockholm, Sweden. magnus.nilsson@ks.se
authors.forename: M
authors.initials: M
authors.lastname: Nilsson
authors.forename: R
authors.initials: R
authors.lastname: Johnsen
authors.forename: W
authors.initials: W
authors.lastname: Ye
authors.forename: K
authors.initials: K
authors.lastname: Hveem
authors.forename: J
authors.initials: J
authors.lastname: Lagergren
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects; D001628:Beverages / Q000009:adverse effects; D016022:Case-Control Studies; D004032:Diet / Q000009:adverse effects; D015444:Exercise; D005260:Female; D005764:Gastroesophageal Reflux / Q000209:etiology* / Q000517:prevention & control; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects; D017673:Sodium Chloride, Dietary / Q000009:adverse effects
chemical_list: D017673:Sodium Chloride, Dietary