title: Evaluation of the relationship between major dietary patterns and uninvestigated reflux among Iranian adults.
abstract: OBJECTIVE
  The etiology of uninvestigated reflux is largely unknown. Although diet has been associated with uninvestigated reflux, the role of dietary patterns is not clear yet. The aim of this study was to investigate dietary patterns in relation to uninvestigated reflux among Iranian adults.
  
  
  METHODS
  This cross-sectional study was carried out within the framework of SEPAHAN (Study on the Epidemiology of Psychological, Alimentary Health and Nutrition) among Iranian adults. Dietary data were collected using a self-administered, 106-item, dish-based, semiquantitative food frequency questionnaire. Uninvestigated reflux was considered to be present when an individual reported to be suffering from heartburn sometimes or frequently in the preceding 3 mo. Specific dietary patterns were identified using factor analysis.
  
  
  RESULTS
  Complete information from 3846 individuals was available for statistical analysis. We identified four major dietary patterns: fast food, traditional, vegetarian, and Western. After controlling for potential confounders, no overall significant associations were found between these dietary patterns and uninvestigated reflux. However, participants in the third quintile of the traditional dietary pattern had greater odds of uninvestigated reflux, either in the crude (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.09-1.74) or the adjusted (OR, 1.52; 95% CI, 1.16-2.00) model taking into account different confounders. After controlling for age, men in the second (OR, 1.64; 95% CI, 1.10-2.45) and women in the fourth (OR, 1.47; 95% CI, 1.02-2.11) quintiles of the fast food dietary pattern were more likely to have uninvestigated reflux. Moreover, in the age-adjusted model, men in the second (OR, 1.72; 95% CI, 1.14-2.59) and fourth (OR, 1.56; 95% CI, 1.03-2.35) quintiles, and women in the second (OR, 1.48; 95% CI, 1.08-2.04) quintile of the traditional dietary pattern were at higher risk for being diagnosed with uninvestigated reflux.
  
  
  CONCLUSIONS
  Although the present study showed no statistically significant associations between major dietary patterns and the risk for uninvestigated reflux, relative positive associations were found between uninvestigated reflux and adherence to either fast food or traditional dietary patterns, suggesting that these contribute to the risk for developing reflux.
authors.affiliation: Food Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Khodarahmi
authors.affiliation: Food Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: azadbakht@hlth.mui.ac.ir.
authors.forename: Leila
authors.initials: L
authors.lastname: Azadbakht
authors.affiliation: Integrative Functional Gastroenterology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Daghaghzadeh
authors.affiliation: University of Adelaide Discipline of Medicine and NHMRC Centre of Research Excellence of Translating Nutritional Science to Good Health, Adelaide, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Feinle-Bisset
authors.affiliation: Integrative Functional Gastroenterology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: Ammar Hassanzadeh
authors.initials: AH
authors.lastname: Keshteli
authors.affiliation: Integrative Functional Gastroenterology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Afshar
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Awat
authors.initials: A
authors.lastname: Feizi
authors.affiliation: Food Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Esmaillzadeh
authors.affiliation: Integrative Functional Gastroenterology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Peyman
authors.initials: P
authors.lastname: Adibi
mesh_terms: D000328:Adult; D000367:Age Factors; D003430:Cross-Sectional Studies; D059026:Diagnostic Self Evaluation; D004032:Diet / Q000009:adverse effects* / Q000208:ethnology; D014676:Diet, Vegetarian / Q000009:adverse effects / Q000208:ethnology; D066273:Diet, Western / Q000009:adverse effects / Q000208:ethnology; D005163:Factor Analysis, Statistical; D057140:Fast Foods / Q000009:adverse effects*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology*; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D009749:Nutrition Surveys; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors
keywords: Adult; Factor analysis; Fast food; Reflux disease; Traditional diet; Vegetarian; Western dietary pattern