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DIETARY VITAMIN E DEFICIENCY AS A MODIFIER OF THE ASSOCIATIONS OF RESPIRATORY OUTCOMES WITH AIR POLLUTION IN ADOLESCENTS
Citation:
BURNS, J. S., D. W. DOCKERY, L. M. NEAS, J. SCHWARTZ, B. COULL, AND F. E. SPEIZER. DIETARY VITAMIN E DEFICIENCY AS A MODIFIER OF THE ASSOCIATIONS OF RESPIRATORY OUTCOMES WITH AIR POLLUTION IN ADOLESCENTS. Presented at International Society for Environmental Epidemiology Annual Meeting, Paris, FRANCE, September 02 - 06, 2006.
Description:
Introduction: We investigated whether low dietary intake of the lipophilic antioxidant vitamin E may act as a modifier of chronic air pollution's associations with respiratory outcomes among adolescents due to an increased respiratory response to the oxidative effects of air pollution.
Methods: In twelve U.S. and Canadian cities 2,112 adolescents, ages 16-19, completed respiratory and semiquantitative food frequency questionnaires during the academic year 1998-1999. Historic city-specific annual mean air pollution measured as coarse particulate matter (PM10-2.1), respirable particulate matter (PM2.1), sulfate and nonsulfate particles, particle acidity, black carbon, sulfur dioxide, daytime ozone in these cities during 1989-1991 was used. We assessed the modification of the associations between air pollution and respiratory outcomes (chronic bronchitic symptoms, attacks of bronchitis, wheeze, asthma) by low dietary vitamin E intake using logistic regression generalized estimating equation models, adjusted for city, gender, race, age, overweight, smoking, household smokers, and mold in the home. Effect estimates for air pollutants were calculated using the 10th to 90th percentile differences. Low dietary vitamin E intake was defined as the lowest quintile of calorie-adjusted intake (less than 5.2 mg) in this cohort, and was compared to the upper four quintiles combined.
Results: Chronic bronchitic symptoms were reported more frequently with an 11 µg/m3 increase in PM2.1 (OR=1.55; 95% CI 1.06, 2.28), a 58 nmol/m3 increase in sulfate particles (OR=1.59; 95% CI 1.08, 2.33), and a 47 nmol/m3 increase in particle acidity (OR=1.66; 95% CI 1.12, 2.44). Positive associations were also found between chronic bronchitic symptoms and all air pollutants, except PM10-2.1. The majority of the students (90%) did not consume the Daily Recommended Intake (15 mg/day) of vitamin E. Chronic bronchitic symptoms associations were stronger for adolescents with low vitamin E intake compared to moderate intake for sulfate particles (OR=4.31; 95% CI 1.72, 10.82 versus OR=1.76; 95% CI 0.99, 3.14), particle acidity (OR=2.99; 95% CI 1.33, 6.71 versus OR=1.78; 95% CI 1.03, 3.10), black carbon (OR=2.98; 95% CI 1.29, 6.89 versus OR=1.50; 95% CI 0.83, 2.72), and ozone (OR=5.18; 95% CI 1.91, 14.07 versus OR=1.41; 95% CI 0.81, 2.46) respectively.
Discussion and Conclusions: These analyses suggest that adolescents with low dietary intake of vitamin E may be particularly susceptible to the adverse respiratory effects of chronic air pollution. This may be due to a decreased ability to protect respiratory tract cell membranes against oxidative stress, and the underlying mechanisms should be investigated.
Funded by NIEHS Grant ES-08391. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.