title: Dietary vitamin A and prevalence of bronchial metaplasia in asbestos-exposed workers.
abstract: The purpose of this investigation was to examine the association between dietary intake of vitamin A in the form of retinol and provitamin A carotenoids and the prevalence of bronchial squamous metaplasia in a sample of asbestos workers from an industrial clinic. Bronchial biopsies were obtained from 49 asbestos workers. Pulmonary function testing was done and in-person interviews were conducted to estimate dietary intake of retinol and provitamin A carotenoids, tobacco exposure, and asbestos exposure. Results indicated that workers with metaplasia reported consuming a significantly lower intake of total vitamin A [2000 retinol equivalents (RE)/d] than did subjects without metaplasia (2710 RE/d, P = 0.02). Logistic regression analyses showed that higher intakes of retinol [odds ratio (OR): 0.31; 95% CI: 0.04, 2.44], provitamin A carotenoids (OR: 0.31; 95% CI: 0.03, 2.84), and total vitamin A (OR: 0.29; 95% CI: 0.03, 2.49) were associated with a nonsignificant reduction in the OR for metaplasia (highest quartile compared with lowest quartile, adjusted ORs). Current smoking (OR: 5.25; 95% CI: 0.50, 55.1) and former smoking (OR: 2.95; 95% CI: 0.31, 28.1) were associated with a nonsignificant increase in the OR for bronchial metaplasia compared with never smoking. Greater airway obstruction [decreased forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)] was associated with an increased OR for metaplasia (OR: 2.86; 95% CI: 1.09, 7.69). These results suggest that a higher (ie, above the median) intake of vitamin A from foods decreases the risk of bronchial metaplasia in workers occupationally exposed to asbestos.
authors.affiliation: Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT 06520-8034, USA. Susan.Mayne@Yale.Edu
authors.forename: S T
authors.initials: ST
authors.lastname: Mayne
authors.forename: C A
authors.initials: CA
authors.lastname: Redlich
authors.forename: M R
authors.initials: MR
authors.lastname: Cullen
mesh_terms: D000328:Adult; D000368:Aged; D001194:Asbestos / Q000009:adverse effects*; D001980:Bronchi / Q000473:pathology*; D001999:Bronchoscopy; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008679:Metaplasia / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D015995:Prevalence; D012129:Respiratory Function Tests; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014801:Vitamin A / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D014801:Vitamin A; D001194:Asbestos