EARLY MARKERS OF ALZHEIMER DISEASE

工作总结：阿尔茨海默病（AD）是几种神经退行性疾病（痴呆）中最普遍的，主要发生在较晚的年龄，偶尔在60岁之前，但更常见于70岁之后。本研究探讨了前瞻性的心理，神经和神经心理学的变化，参与者从巴尔的摩纵向研究老化（BLSA）。对60岁及以上的参与者进行神经学和神经心理学检查，重复在早期对这些受试者进行的许多测试。可能的阿尔茨海默病的诊断遵循NINCDS-ADRDA标准。雌激素替代疗法（ERT）越来越多地被推荐用于绝经后妇女，因为它对老年妇女的身体健康有益。最近的研究表明，ERT可能对认知功能有保护作用，并可能降低阿尔茨海默病的风险。我们在巴尔的摩老龄化纵向研究的非痴呆妇女中测试了ERT是否对记忆有保护作用。研究组包括103名口服或透皮ERT的积极使用者和81名在评估后5年内没有痴呆的从未使用者。各组在教育、健康状况、抑郁症状、年收入和一般语言能力方面相匹配。数据是横截面的。ERT使用者在加州言语学习测试的几项测试中表现出比从未使用者更好的言语学习和记忆，p <0.05，但在图形记忆、心理旋转、注意力或工作记忆测试中没有表现出。ERT的使用与口头信息的编码和检索增强，记忆表现期间对干扰的敏感性降低有关。记忆力的表现并没有随着使用时间的长短而变化，也没有随着同时使用黄体酮而变化。数据表明ERT对记忆有显著的选择性影响。这些发现表明，需要进行纵向研究，以确定ERT是否可以预防非痴呆妇女与年龄相关的记忆力下降。高浓度的脱氢表雄酮（DHEA）可能会预防或逆转正常的与年龄相关的记忆力和认知功能下降。DHEA在美国作为一种非处方补充剂广泛使用，老年人自我处方以阻止与年龄相关的认知以及身体变化。在这项研究中，我们调查了内源性DHEA浓度下降和认知能力下降之间的关系。受试者是巴尔的摩老龄化纵向研究的参与者，该研究是一项社区居住的志愿者样本，首次访视时年龄为22至91岁，其中883名男性随访至31年（平均= 11.55年），每两年重新评估多个认知领域和同期血浆DHEA。言语和视觉记忆的认知测试，2项精神状态测试，语音和语义词流畅性，以及视觉扫描和注意力的测量。血浆DHEA浓度通过标准放射免疫测定法测定。无论是下降速度的DHEA，也不是个人内的平均DHEA浓度与认知状态或认知能力下降。最高和最低DHEA四分位数之间的极端组比较显示没有认知差异，尽管这些组的内源性DHEA浓度差异超过4倍，平均持续时间为12年。我们的纵向结果与以前的横断面研究一致，表明内源性DHEA下降与健康老龄化中的认知状态和认知下降无关。- 认知能力、认知障碍、阿尔茨海默病-人类受试者和人类受试者：仅访谈、问卷调查或调查

Summary of work: Alzheimers disease (AD) is the most widespread among several neurological degenerative diseases (dementias) that occur principally at later ages, occasionally before 60, but more frequently after age 70. This study examines prospective psychological, neurological, and neuropsychological changes in participants from the Baltimore Longitudinal Study of Aging (BLSA). Neurological and neuropsychological examinations are administered to participants aged 60 and older, repeating many of the tests that were administered to these subjects at earlier ages. Diagnoses of probable Alzheimers disease follow the NINCDS-ADRDA criteria. Estrogen replacement therapy (ERT) is increasingly recommended for post-menopausal women due to its beneficial effects on physical health in older women. Recent studies have suggested that ERT may have a protective effect on cognitive function and may reduce the risk for Alzheimers disease. We tested whether ERT had a protective effect on memory in nondemented women from the Baltimore Longitudinal Study of Aging. Study groups included 103 active users of oral or transdermal ERT and 81 never-users who were free of dementia up to 5 years after assessment. Groups were matched on education, health status, depressive symptoms, annual income, and general verbal ability. Data were cross-sectional. ERT users showed significantly better verbal learning and memory than never-users on several measures of the California Verbal Learning Test, p < .05, but not on tests of figural memory, mental rotations, attention or working memory. ERT use was associated with enhanced encoding and retrieval of verbal information, and less sensitivity to interference during memory performance. Memory performance did not vary with duration of use nor with concurrent progesterone use. Data suggest a significant and selective effect of ERT on memory. These findings indicate the need for longitudinal studies to determine whether ERT use protects against age- related memory decline in nondemented women.High concentrations of dehydroepiandrosterone (DHEA) may prevent or reverse normal age-related declines in memory and cognitive function. DHEA is widely available in the United States as an over-the-counter supplement that elderly individuals are self-prescribing to impede age-related cognitive, as well as physical change. In this study, we investigated the relationship between declines in endogenous DHEA concentrations and declines in cognitive performance. Subjects were participants in the Baltimore Longitudinal Study of Aging, a community-dwelling volunteer sample aged 22 to 91 years at initial visit in which 883 men were followed up to 31 years (mean = 11.55 years) with biennial reassessments of multiple cognitive domains and contemporaneous plasma DHEA. Cognitive tests of verbal and visual memory, 2 tests of mental status, phonemic and semantic word fluency, and measures of visuomotor scanning and attention. Plasma DHEA concentrations were determined by standard radioimmunoassay. Neither the rate of decline in DHEA nor the within-individual mean DHEA concentrations were related to cognitive status or cognitive decline. An extreme-groups comparison between the highest and lowest DHEA quartiles revealed no cognitive differences, despite the fact that these groups differed in endogenous DHEA concentration by more than a factor of 4 for an average duration of 12 years. Our longitudinal results are consistent with previous cross- sectional studies suggesting that endogenous decline in DHEA is independent of cognitive status and cognitive decline in healthy aging. - cognitive ability, cognitive impairment, Alzheimer's disease - Human Subjects & Human Subjects: Interview, Questionaires, or Surveys Only