Supplemental Selenium and Vitamin E and Pulmonary Function

BACKGROUND:

There is compelling evidence from observational epidemiologic studies that intakes of nutrients with antioxidant properties are associated with reduced risks of chronic obstructive disease (COPD) and increased lung function. This study is ancillary to the multisite Selenium and Vitamin E Cancer Prevention Trial (SELECT), a 4-arm placebo-controlled, double-blinded randomized trial in 35,000 men testing whether daily supplementation with vitamin E (400mg alpha-tocopherol), selenium (200 micrograms selenomethionine) or both vitamin E and selenium can prevent prostate cancer.

DESIGN NARRATIVE:

This study is ancillary to the multisite Selenium and Vitamin E Cancer Prevention Trial (SELECT), a 4-arm placebo-controlled, double-blinded randomized trial in 35,000 men testing whether daily supplementation with vitamin E (400mg alpha-tocopherol), selenium (200 micrograms selenomethionine) or both vitamin E and selenium can prevent prostate cancer. A total of 3,000 SELECT participants will be enrolled for this respiratory ancillary study, and data collection will be extended to include pulmonary function, respiratory disease, and respiratory symptoms. Biological measures of nutrient exposure (serum vitamin E and selenium) and plasma lipids (total and high-density lipoprotein cholesterol) will be collected on all participants and oxidant burden (urinary F2-isoprostane) on a sub sample of heavy smokers and men with COPD. The primary outcome will be change over about 36 months in forced expiratory volume in the first second (FEV1). FEV1 is a valid and reliable measure of respiratory function that strongly predicts COPD and mortality. Extensive data on diet and dietary supplement use are being collected by the SELECT parent study. All specific aims examine pre-specified contrasts between the 4 arms of the SELECT randomized trial. The underlying hypothesis is that supplements will reduce the age related decline in FEV1 and thus at the 3-year follow-up FEV1, which will be tested in longitudinal and cross-sectional models. A secondary aim considers whether the effect of supplementation is greater among smokers (high burden of exogenous oxidants) who, by purposive selection of the study sites, will comprise about 25% of the sample.

• Chronic Obstructive Pulmonary Disease
• Lung Diseases
• Lung Diseases, Obstructive

• Dietary Supplement: Vitamin E
  vitamin E (400 IU/day all rac-α-tocopheryl acetate)
  Other Name: all rac-α-tocopheryl acetate
• Dietary Supplement: Selenium
  selenium (200 μg/d L-selenomethionine)
  Other Name: L-selenomethionine

• Experimental: Vitamin E and placebo
  Vitamin E alone
  Intervention: Dietary Supplement: Vitamin E
• Experimental: Selenium and placebo
  Selenium alone
  Intervention: Dietary Supplement: Selenium
• Experimental: Vitamin E and selenium
  Vitamin E and selenium combined
  Interventions:

  • Dietary Supplement: Vitamin E
  • Dietary Supplement: Selenium
• Placebo Comparator: Placebo and placebo
  Double placebo

• Goodman PJ, Tangen CM, Darke AK, Arnold KB, Hartline J, Yee M, Anderson K, Caban-Holt A, Christen WG, Cassano PA, Lance P, Klein EA, Crowley JJ, Minasian LM, Meyskens FL. Opportunities and challenges in incorporating ancillary studies into a cancer prevention randomized clinical trial. Trials. 2016 Aug 12;17:400. doi: 10.1186/s13063-016-1524-9.
• Cassano PA, Guertin KA, Kristal AR, Ritchie KE, Bertoia ML, Arnold KB, Crowley JJ, Hartline J, Goodman PJ, Tangen CM, Minasian LM, Lippman SM, Klein E. A randomized controlled trial of vitamin E and selenium on rate of decline in lung function. Respir Res. 2015 Mar 11;16:35. doi: 10.1186/s12931-015-0195-5.

Eligibility criteria:

• age ≥ 55 y (≥ 50 y in African-Americans)
• serum prostate-specific antigen ≤ 4ng/mL
• no clinical evidence of prostate cancer

Exclusion criteria:

• Off both SELECT supplements