SLEEP & MENTAL FUNCTION IN THE AGED--ANABOLIC INFLUENCE

老年人抱怨记忆力减退、睡眠障碍、虚弱和丧失 瘦体重;与年龄相关的认知能力下降，睡眠 数量和质量，瘦体重（LBM）和合成代谢激素， 生长激素（GH）是有据可查的。 初步证据来自 我们的数据库显示，这些变化可能是相互关联的。 我们 观察到合成代谢状态（如血浆胰岛素样生长指数 因子，或IGF），与更好的 睡眠质量（增加慢波睡眠，减少觉醒， 睡眠碎片减少）和认知，特别是记忆 注意力集中在健康的老年人身上。 这些初步结果使我们 假设外周合成代谢状态的测量（例如，性 激素，LBM，特别是GH和IGF）可能指示中枢神经系统 老年人的中枢神经系统（CNS）状态。 虽然GH和IGF是众所周知的， 指标躯体状态，它们与CNS功能的关系在很大程度上 忽视 在老年人中没有这样的研究， 睡眠和认知能力受损，GH和IGF水平较低 水平比年轻人。 这项研究将扩大我们现有的数据。 基础，以澄清合成代谢激素状态，睡眠 质量和认知功能的控制子集从我们的 现有的健康老年对照成人样本（n=280）。 我们的假设将在大约140名对照受试者中进行测试。 到 评估合成代谢状态，将通过缓慢抽取泵采集血液样本 在24小时内。 将分析合并血浆的24小时积分 GH、IGF、皮质醇、游离睾酮（男性）和甲状腺激素水平 激素（T3、T4）。 生长激素和睾酮的结合蛋白也将被 测定了 24小时尿雌酮和雌二醇 以女性为衡量标准。 将通过生物阻抗测定瘦体重。 睡眠变量将包括睡眠和清醒的阶段，睡眠 分段（阶段变化）和巩固（睡眠期时间），如 以及总EEG δ活动（计算机导出）。 关系 之间的合成代谢状态和睡眠将确定使用多个 回归技术 认知测试将包括Rivermead行为测试 记忆，痴呆评定量表，配对联想学习任务， 工作记忆任务（Verbal Sets），选择性注意任务（Brief Test 注意力）和语言流畅性测试。 合成代谢之间的关系 还将使用多元回归确定状态和认知 技术. 这些研究将确定合成代谢激素的水平， 与高睡眠质量和良好的认知功能有关， 老年人。 他们还将促进适当的生长激素的设计， 针对改善认知/睡眠的IGF干预研究 前辈 我们更大的长期目标是阐明生长激素的作用， IGF和相关激素在衰老的神经生物学中的作用。

Older adults complain of memory loss, sleep disorders, frailty, and loss of lean body mass; age-related decreases in cognitive ability, sleep quantity and quality, lean body mass (LBM), and anabolic hormones such as growth hormone (GH) are well-documented. Preliminary evidence from our database suggests that these changes may be interrelated. We observed that anabolic status (as indexed by plasma insulin-like growth factor, or IGF), correlates significantly and positively with better sleep quality (increased slow wave sleep, decreased wakefulness, and decreased fragmentation of sleep) and with cognition, particularly memory and attention in healthy seniors. These preliminary results lead us to hypothesize that measures of peripheral anabolic status (e.g., sex hormones, LBM, and particularly GH and IGF) may index central nervous system (CNS) status in older adults. While GH and IGF are well-known to index somatic status, their relationship to CNS function has been largely ignored. There are no such studies in the elderly, who are more likely to suffer from impaired sleep and cognition and have lower GH and IGF levels than the young. The proposed study will expand our existing data base to clarify the relationships among anabolic hormone status, sleep quality and cognitive function in subsets of controls drawn from our already-existing samples of healthy older control adults (n=280). Our hypotheses will be tested in approximately 140 control subjects. To evaluate anabolic status, blood will be sampled via slow withdrawal pump across 24-hours. Pooled plasma will be assayed for integrated 24-hour levels of GH, IGF, cortisol, free testosterone (in men), and thyroid hormones (T3,T4). Binding proteins for GH and testosterone will also be measured. Twenty-four hour urinary estrone and estradiol will be measured in women. Lean body mass will be determined via bio-impedance. Sleep variables will include stages of sleep and wakefulness, sleep fragmentation (stage changes) and consolidated (sleep period time), as well as total EEG delta activity (computer derived). Relationships between anabolic status and sleep will be identified using multiple regression techniques. Cognitive tests will include Rivermead Behavioral Memory, Dementia Rating Scale, a paired associates learning task, a working memory task (Verbal Sets), a selective attention task (Brief Test of Attention), and a verbal fluency test. Relationships between anabolic status and cognition will also be identified using multiple regression techniques. These studies will identify levels of anabolic hormones that are associated with high sleep quality and good cognitive function in senior adults. They will also foster the design of appropriate GH and IGF intervention studies targeted at improving cognition/sleep in seniors. Our larger long-term objective is to elucidate the role of GH and IGF and related hormones in the neurobiology of aging.