Supplemental Se and Vitamin E and Pulmonary Function

描述(由申请人提供)： 这项拟议的项目是一项随机临床试验，测试补充硒和/或维生素E是否会影响肺功能。来自观察性流行病学研究的令人信服的证据表明，抗氧化剂的高摄入量与慢性阻塞性疾病(COPD)风险的降低和肺功能的增加有关。这项建议是多点硒和维生素E癌症预防试验(SELECT)的一项辅助研究，该试验是一项四组安慰剂对照的双盲随机试验，有32,400名男性参加，测试每天补充维生素E(400毫克α-生育酚)、硒(200微克硒蛋氨酸)或同时补充维生素E和硒是否可以预防前列腺癌。我们将为这项呼吸辅助研究招募3000名精选参与者，并扩大数据收集范围，以包括肺功能、呼吸系统疾病和呼吸道症状。我们还将收集所有参与者的营养暴露(血清维生素E和硒)和血脂(总和高密度脂蛋白胆固醇)的生物学指标，以及重度吸烟者和患有COPD的男性样本的氧化负荷(尿F2-异前列腺素)。主要结果将是第一秒用力呼气量(FEV1)在基线和第三年之间的变化。FEV1是一种有效和可靠的呼吸功能指标，可强烈预测COPD和死亡率。精选父母研究正在收集有关饮食和膳食补充剂使用的广泛数据。所有特定目标检查选定的随机试验的4个手臂之间的预先指定的对比。基本的假设是，抗氧化剂将减少与年龄相关的FEV1下降，因此在3年的随访中，接受抗氧化剂补充剂的组的FEV1将高于对照组。第二个目的是考虑补充的效果在吸烟者中是否更大(外源性氧化剂的高负担)，通过有目的地选择研究地点，他们将占样本的25%。拟议的研究解决了关于饮食和肺部疾病的重要和及时的问题，并以成本效益的方式利用了SELECT的研究基础设施。这项研究可能具有巨大的公共卫生意义，因为补充抗氧化剂营养素将是降低肺部疾病发病率和死亡率的一种廉价和可行的方法。

DESCRIPTION (provided by applicant): This proposed project is a randomized clinical trial testing whether supplementation with selenium and/or vitamin E affects pulmonary function. There is compelling evidence from observational epidemiologic studies that high antioxidant intakes are associated with reduced risks of chronic obstructive disease (COPD) and increased lung function. This proposal is an ancillary study to the multisite selenium and Vitamin E Cancer Prevention Trial (SELECT), a 4-arm placebo-controlled, double-blinded randomized trial in 32,400 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. We will enroll 3,000 SELECT participants for this respiratory ancillary study, and extend data collection to include pulmonary function, respiratory disease, and respiratory symptoms. We also will collect biological measures of nutrient exposure (serum vitamin E and selenium) and plasma lipids (total and high-density lipoprotein cholesterol) 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 between baseline and year 3 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 antioxidants will reduce the age related decline in FEV1, and thus at the 3-year follow-up FEV1 will be higher in the groups receiving antioxidant supplements compared to controls. 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 25% of the sample. The proposed study addresses important and timely questions about diet and lung disease, and makes cost efficient use of the research infrastructure of SELECT. This study could have enormous public health significance, because supplementation with antioxidant nutrients would be an inexpensive and practicable means to reduce morbidity and mortality from pulmonary disease.