Night Shift Work and Hormone Levels in Men

描述（由申请人提供）：拟议研究的主要目的是确定在健康男性样本中夜间工作是否与以下情况相关：尿中6-硫氧褪黑激素浓度降低；血清睾酮、二氢睾酮（DHT）、3-a雄甾二醇葡萄糖醛酸盐、硫酸脱氢表雄酮（DHEA）、雌酮和雌二醇浓度升高；尿中以下雄激素代谢物浓度升高：偶联睾酮、二氢睾酮、依替胆醇酮、雄酮、雄甾二醇和脱氢表雄酮；血清性激素结合球蛋白浓度降低。该研究还将调查：1)在夜间工作的男性中，与夜间睡眠相比，白天睡眠时尿液中褪黑素水平是否较低，血清和尿液中上述雄激素和代谢物水平是否较高；2)人类生物钟基因的特定多态性是否与个体适应夜班工作的能力有关。西雅图市区将招募大约200名夜班男性保健工作者和150名白班男性保健工作者。符合条件的参与者必须是22-55岁，每周工作至少20小时，不服用激素制剂，无前列腺癌病史。这项研究将允许夜班和白班工人的受试者间比较，以及夜班工人白天睡眠和夜间睡眠的受试者内比较。参与包括面对面的面试，对轮班工作的适应能力的评估，以及在工作和睡眠期间收集血液和尿液。睡眠质量和睡眠时间将通过活动记录仪在与样本采集相对应的睡眠期间测量。将收集可能与所研究的激素有关的因素的信息，如饮酒、药物使用和样本采集期间的日照时间。将对血清和尿液样本进行上述激素和代谢物的检测，并对血液样本进行人类CLOCK、PER2和PER3基因特定多态性的基因分型。这项研究将首次评估夜班工作对褪黑激素和前列腺癌病因中最感兴趣的激素的影响。研究结果将为夜班工作与癌症风险之间的潜在生物学基础提供重要的新信息。

DESCRIPTION (provided by applicant): The primary objective of the proposed study is to determine whether working at night is associated with the following in a sample of healthy men: decreased urinary concentration of 6-sulphatoxymelatonin; increased serum concentrations of testosterone, dihydrotesterone (DHT), 3-a androstanediol glucuronide, dehydroepiandrosterone (DHEA) sulfate, estrone, and estradiol; increased urinary concentrations of the following androgen metabolites: conjugated testosterone, DHT, etiocholanolone, androsterone, androstanediol, and DHEA; and decreased serum concentration of sex hormone-binding globulin. The study will also investigate: 1) whether urinary levels of melatonin are lower and serum and urinary levels of the androgens and metabolites listed above are higher during daytime sleep relative to nighttime sleep among men who work at night; and 2) if specific polymorphisms of the human circadian clock genes are associated with an individual's ability to adapt to night shift work. Approximately 200 male health care workers who work the night shift and 150 who work the day shift will be recruited in the Seattle metropolitan area. Eligible participants must be 22-55 years old, employed for at least 20 hours/week, not taking hormone preparations, and have no history of prostate cancer. This study will allow for both between-subject comparisons of night shift v. day shift workers, and within-subject comparisons during day sleep v. night sleep among night shift workers. Participation includes an in-person interview, assessment of ability to adapt to shiftwork, and blood and urine collections during both work and sleep periods. Sleep quality and quantity will be measured via actigraphy during the sleep periods corresponding to sample collection. Information will be collected on factors that may be related to the hormones under study, such as alcohol consumption, medication use, and hours of daylight during sample collection. Serum and urine samples will be assayed for the hormones and metabolites listed above, and blood samples will be genotyped for specific polymorphisms of the human CLOCK, PER2, and PER3 genes. This study will be the first effort to assess the effects of night shift work on melatonin and the hormones of most interest in the etiology of prostate cancer. Results will provide important new information regarding the underlying biological basis of the emerging evidence linking night shift work with cancer risk.