title: A randomized controlled trial of vitamin E and selenium on rate of decline in lung function.
abstract: BACKGROUND
  The intake of nutrients with antioxidant properties is hypothesized to augment antioxidant defenses, decrease oxidant damage to tissues, and attenuate age-related rate of decline in lung function. The objective was to determine whether long-term intervention with selenium and/or vitamin E supplements attenuates the annual rate of decline in lung function, particularly in cigarette smokers.
  
  
  METHODS
  The Respiratory Ancillary Study (RAS) tested the single and joint effects of selenium (200 μg/d L-selenomethionine) and vitamin E (400 IU/day all rac-α-tocopheryl acetate) in a randomized double-blind placebo-controlled trial. At the end of the intervention, 1,641 men had repeated pulmonary function tests separated by an average of 3 years. Linear mixed-effects regression models estimated the effect of intervention on annual rate of decline in lung function.
  
  
  RESULTS
  Compared to placebo, intervention had no main effect on either forced expiratory volume in the first second (FEV1) or forced expiratory flow (FEF25-75). There was no evidence for a smoking by treatment interaction for FEV1, but selenium attenuated rate of decline in FEF25-75 in current smokers (P = 0.0219). For current smokers randomized to selenium, annual rate of decline in FEF25-75 was similar to the annual decline experienced by never smokers randomized to placebo, with consistent effects for selenium alone and combined with vitamin E.
  
  
  CONCLUSIONS
  Among all men, there was no effect of selenium and/or vitamin E supplementation on rate of lung function decline. However, current smokers randomized to selenium had an attenuated rate of decline in FEF25-75, a marker of airflow.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier: NCT00241865 .
authors.affiliation: Division of Nutritional Sciences, Cornell University, 209 Savage Hall, Ithaca, NY, 14853, USA. pac6@cornell.edu.|Department of Healthcare Policy and Research, Division of Biostatistics and Epidemiology, Weill Cornell Medical College, New York, NY, USA. pac6@cornell.edu.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cassano
authors.affiliation: Division of Nutritional Sciences, Cornell University, 209 Savage Hall, Ithaca, NY, 14853, USA. kam84@cornell.edu.|Current address: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, MD, USA. kam84@cornell.edu.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Guertin
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, WA, USA. Alan.Kristal@fhcrc.org.|Fred Hutchinson Cancer Research Center, Seattle, WA, USA. Alan.Kristal@fhcrc.org.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kristal
authors.affiliation: Division of Nutritional Sciences, Cornell University, 209 Savage Hall, Ithaca, NY, 14853, USA. ker32@cornell.edu.|Current address: Loyola Department of Oral and Maxillofacial Surgery, Loyola University, Chicago, IL, USA. ker32@cornell.edu.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Ritchie
authors.affiliation: Division of Nutritional Sciences, Cornell University, 209 Savage Hall, Ithaca, NY, 14853, USA. monica.bertoia@gmail.com.|Current address: Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA. monica.bertoia@gmail.com.
authors.forename: Monica L
authors.initials: ML
authors.lastname: Bertoia
authors.affiliation: SWOG Statistical Center, Seattle, WA, USA. karnold@fhcrc.org.
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Arnold
authors.affiliation: SWOG Statistical Center, Seattle, WA, USA. johnc@crab.org.
authors.forename: John J
authors.initials: JJ
authors.lastname: Crowley
authors.affiliation: SWOG Statistical Center, Seattle, WA, USA. joannh@crab.org.
authors.forename: JoAnn
authors.initials: J
authors.lastname: Hartline
authors.affiliation: SWOG Statistical Center, Seattle, WA, USA. pgoodman@fhcrc.org.
authors.forename: Phyllis J
authors.initials: PJ
authors.lastname: Goodman
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, WA, USA. ctangen@fhcrc.org.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Tangen
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, USA. minasilo@mail.nih.gov.
authors.forename: Lori M
authors.initials: LM
authors.lastname: Minasian
authors.affiliation: University of California San Diego, Moores Cancer Center, La Jolla, CA, USA. slippman@ucsd.edu.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Lippman
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA. Kleine@ccf.org.
authors.forename: Eric
authors.initials: E
authors.lastname: Klein
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage; D019587:Dietary Supplements; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests / Q000639:trends; D012643:Selenium / Q000008:administration & dosage*; D012907:Smoking / Q000188:drug therapy* / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D012643:Selenium