title: The vitamin E isoforms α-tocopherol and γ-tocopherol have opposite associations with spirometric parameters: the CARDIA study.
abstract: BACKGROUND
  Clinical studies of the associations of vitamin E with lung function have reported conflicting results. However, these reports primarily examine the α-tocopherol isoform of vitamin E and have not included the isoform γ-tocopherol which we recently demonstrated in vitro opposes the function of α-tocopherol. We previously demonstrated, in vitro and in animal studies, that the vitamin E isoform α-tocopherol protects, but the isoform γ-tocopherol promotes lung inflammation and airway hyperresponsiveness.
  
  
  METHODS
  To translate these findings to humans, we conducted analysis of 4526 adults in the Coronary Artery Risk Development in Young Adults (CARDIA) multi-center cohort with available spirometry and tocopherol data in blacks and whites. Spirometry was obtained at years 0, 5, 10, and 20 and serum tocopherol was from years 0, 7 and 15 of CARDIA.
  
  
  RESULTS
  In cross-sectional regression analysis at year 0, higher γ-tocopherol associated with lower FEV1 (p = 0.03 in blacks and p = 0.01 in all participants) and FVC (p = 0.01 in blacks, p = 0.05 in whites, and p = 0.005 in all participants), whereas higher α-tocopherol associated with higher FVC (p = 0.04 in blacks and whites and p = 0.01 in all participants). In the lowest quartile of α-tocopherol, higher γ-tocopherol associated with a lower FEV1 (p = 0.05 in blacks and p = 0.02 in all participants). In contrast, in the lowest quartile of γ-tocopherol, higher α-tocopherol associated with a higher FEV1 (p = 0.03) in blacks. Serum γ-tocopherol >10 μM was associated with a 175-545 ml lower FEV1 and FVC at ages 21-55 years.
  
  
  CONCLUSIONS
  Increasing serum concentrations of γ-tocopherol were associated with lower FEV1 or FVC, whereas increasing serum concentrations of α-tocopherol was associated with higher FEV1 or FVC. Based on the prevalence of serum γ-tocopherol >10 μM in adults in CARDIA and the adult U.S. population in the 2011 census, we expect that the lower FEV1 and FVC at these concentrations of serum γ-tocopherol occur in up to 4.5 million adults in the population.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Marchese
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Laura A
authors.initials: LA
authors.lastname: Colangelo
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Avila
authors.forename: David R
authors.initials: DR
authors.lastname: Jacobs
authors.forename: Myron
authors.initials: M
authors.lastname: Gross
authors.forename: Akshay
authors.initials: A
authors.lastname: Sood
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.affiliation: Division of Allergy and Immunology, Feinberg School of Medicine, Northwestern University, McGaw M304, 240 E, Huron, Chicago, IL, 60611, USA. j-cook-mills@northwestern.edu.
authors.forename: Joan M
authors.initials: JM
authors.lastname: Cook-Mills
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D013147:Spirometry / Q000379:methods / Q000592:standards; D014810:Vitamin E / Q000097:blood; D055815:Young Adult; D024502:alpha-Tocopherol / Q000097:blood*; D024504:gamma-Tocopherol / Q000097:blood*
chemical_list: D015415:Biomarkers; D014810:Vitamin E; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol