CAFFEINE AND HUMAN REPRODUCTION

本研究的目的是探讨 咖啡因摄入与人类生殖之间的关系 初步数据 表明咖啡因可能对女性和男性生殖系统产生不利影响 性能 咖啡因摄入的高流行率表明， 大部分人口可能受到影响。 这 这项研究旨在评估咖啡因对糖尿病风险的影响。 自然流产和精液质量，并检查的作用， 咖啡因代谢和激素功能可能在调解任何 咖啡因对生殖的影响 有四个组成部分：（1） 咖啡因与自然流产的关系将通过以下方法进行检查： 对5300名孕妇的前瞻性研究数据进行分析。 受试者是一个种族多样的健康维护小组的成员， 在第一次产前预约时招募， 7-13怀孕几周。 访谈数据将提供以下信息： 咖啡因摄入量和潜在的混杂变量。 咖啡因 摄入量和其他危险因素将在有和没有 自然流产 是否存在某些因素，例如 恶心，咖啡因摄入量的变化或含咖啡因的类型 同时亦会研究饮用的饮品的影响风险。 (2)的作用 咖啡因代谢在决定自然流产的风险将 通过表征样品中的咖啡因代谢来检查， 来自第1部分的约140例病例和140例对照。 每个女人 将提交一个单一的第一次晨尿后摄入的测试剂量 咖啡因 将确定咖啡因的主要代谢物， 咖啡因代谢速率和三种酶活性 根据代谢物比率计算。 是否是新陈代谢速度变慢 或酶活性的改变改变自然流产的风险 与咖啡因摄入有关的因素 (3)效果 咖啡因对荷尔蒙功能和排卵的影响将由 分析在一项前瞻性研究中收集的数据， 有怀孕风险的妇女（来自同一健康计划）。 每日 收集第一次晨尿样本长达六个月， 分析雌激素和孕酮代谢物，提供 关于排卵发生和卵泡长度的信息， 黄体期 访谈数据将提供有关咖啡因的信息 消费和潜在的混杂变量。 咖啡因是否 与激素功能的改变有关， 周期，尿类固醇结合物水平的改变，或特定的 将检查荷尔蒙变化的模式。 这些女人的唾液 将对咖啡因进行检测，以提供暴露的生物标志物。 (4)的 咖啡因对精液质量的影响将通过分析数据来检验 从第三部分的一组妇女的丈夫那里收集的数据。 精液 已从大约160名男子身上收集了样本，并将 分析精子计数，活力和形态，而精液和 将分析唾液中的咖啡因。 访谈数据将提供 咖啡因摄入量和潜在混杂变量的信息。 第1、3和4部分的数据收集工作已经完成。 组件 2是一项新的研究。 从这些研究中获得的信息 可用于预防 咖啡因

The objective of the proposed research is to examine the relationship between caffeine intake and human reproduction. Preliminary data indicate that caffeine may adversely affect female and male reproductive performance. The high prevalence of caffeine intake suggests that a large proportion of the population is potentially affected. This research is intended to estimate the effects of caffeine on risk of spontaneous abortion and on semen quality, and to examine the roles that caffeine metabolism and hormonal function might play in mediating any effects of caffeine on reproduction. There are four components: (1) The relationship of caffeine to spontaneous abortion will be examined by analyzing data collected from a prospective study of 5300 pregnant women. Subjects were members of an ethnically diverse health maintenance organization, recruited at first prenatal appointment and interviewed at 7-13 weeks gestation. Interview data will provide information on caffeine consumption and potential confounding variables. Caffeine intake and other risk factors will be compared in women with and without spontaneous abortion. Whether certain factors, such as the presence of nausea, changes in caffeine consumption or the type of caffeinated beverage consumed affect risk will also be examined. (2) The role of caffeine metabolism in determining the risk of spontaneous abortion will be examined by characterizing caffeine metabolism in a sample of approximately 140 cases and 140 controls from component 1. Each woman will submit a single first morning urine after ingestion of a test dose of caffeine. The major metabolites of caffeine will be determined, and the rate of caffeine metabolism and activities of three specific enzymes calculated from metabolite ratios. Whether a slower rate of metabolism or alteration in enzyme activity modify the risk for spontaneous abortion associated with caffeine ingestion will be determined. (3) The effect of caffeine on hormonal function and ovulation will be studied by analyzing data collected in a prospective study of approximately 400 women (from the same health plan) at risk of becoming pregnant. Daily first morning urine samples were collected for up to six months and will be analyzed for estrogen and progesterone metabolites, providing information on occurrence of ovulation and length of follicular and luteal phases. Interview data will provide information on caffeine consumption and potential confounding variables. Whether caffeine is associated with alteration in hormonal function, increases in anovulatory cycles, alterations in urinary steroid conjugate levels, or specific patterns of hormonal change will be examined. Saliva from these women will be assayed for caffeine to provide a biomarker of exposure. (4) The effect of caffeine on semen quality will be examined by analyzing data collected from a group of husbands of women from component 3. Semen samples have been collected from approximately 160 men, and will be analyzed for sperm count, motility, and morphometry, while semen and saliva will be analyzed for caffeine. Interview data will provide information on caffeine consumption and potential confounding variables. Data collection for components 1, 3, and 4 has been completed. Component 2 is a newly proposed study. The information gained from these studies could be used in the prevention of adverse reproductive effects of caffeine.