Supplemental Se and Vitamin E and Pulmonary Function

描述（由申请人提供）： 该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，高抗氧化剂摄入量与慢性阻塞性疾病（COPD）风险降低和肺功能增强相关。 这项提案是多部位硒和维生素E癌症预防试验（SELECT）的辅助研究，这是一项在32，400名男性中进行的4臂安慰剂对照，双盲随机试验，旨在测试每日补充维生素E（400 mg α-生育酚），硒（200微克硒代蛋氨酸）或维生素E和硒是否可以预防前列腺癌。 我们将招募3，000名SELECT参与者参加这项呼吸辅助研究，并将数据收集扩展到包括肺功能、呼吸系统疾病和呼吸系统症状。 我们还将收集所有参与者的营养素暴露（血清维生素E和硒）和血脂（总胆固醇和高密度脂蛋白胆固醇）的生物学指标，以及重度吸烟者和COPD男性子样本的氧化剂负荷（尿F2-异前列烷）。 主要结果将是基线和第3年之间第一秒用力呼气量（FEV 1）的变化。 FEV 1是一种有效且可靠的呼吸功能指标，可有力预测COPD和死亡率。 SELECT母体研究正在收集有关饮食和膳食补充剂使用的广泛数据。 所有特定目标均检查SELECT随机试验4组之间的预先规定的对比。 潜在的假设是，抗氧化剂将减少与年龄相关的FEV 1下降，因此在3年随访时，与对照组相比，接受抗氧化剂补充剂的组的FEV 1将更高。 第二个目的是考虑补充剂的效果是否在吸烟者（外源性氧化剂的高负担）中更大，通过有目的地选择研究中心，将占样本的25%。 拟议的研究解决了有关饮食和肺部疾病的重要和及时的问题，并使SELECT的研究基础设施的成本效益。 这项研究可能具有巨大的公共卫生意义，因为补充抗氧化营养素将是降低肺部疾病发病率和死亡率的廉价和可行的方法。

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.