Age-associated cognitive changes in community dwelling adults

虽然临床心脑血管疾病是认知能力下降和痴呆的危险因素，但对于没有这些疾病的个体，血管健康与认知之间的关系知之甚少。颈动脉内膜内侧厚度（IMT）是一种亚临床血管疾病的测量指标，与认知功能的同时下降有关，但相对较少的研究调查了颈动脉内膜内侧厚度与预期认知功能下降之间的纵向关系。我们在巴尔的摩老龄化纵向研究（BLSA）中检查了538名无已知心脑血管和神经系统疾病的参与者（年龄在20至93岁之间，39%为男性，66%为白人）的颈动脉IMT与认知功能的预期轨迹的关系。在长达11年的随访中，参与者接受了最初的颈动脉超声检查和多达8次的重复神经心理测试。混合效应回归分析调整了年龄、性别、种族、教育程度、平均动脉压、体重指数、总胆固醇、吸烟、抑郁症状和心血管药物使用情况。随着时间的推移，颈动脉IMT越大的人在言语和非言语记忆的多项测试以及语义关联流畅性和执行功能的测试中表现出加速的性能下降。在没有血管和神经疾病的社区居民中，颈动脉IMT预测加速的认知衰退，特别是在记忆领域。

Although clinical cardiovascular and cerebrovascular diseases are established risk factors for cognitive decline and dementia, less is known about the relations between vascular health and cognition among individuals without these diseases. Carotid intimal medial thickness (IMT), a measure of subclinical vascular disease, is associated with concurrent decrements in cognitive function, but relatively little research has examined longitudinal relations between carotid IMT and prospective cognitive decline. We examined relations of carotid IMT to prospective trajectories of cognitive function among 538 (aged 20 to 93, 39% male, 66% white) participants in the Baltimore Longitudinal Study of Aging (BLSA) free of known cardiovascular, cerebrovascular, and neurological disease. Participants underwent initial carotid ultrasonography and repeat neuropsychological testing on up to 8 occasions over up to 11 years of follow-up. Mixed-effects regression analyses were adjusted for age, gender, race, education, mean arterial pressure, body mass index, total cholesterol, smoking, depressive symptoms, and cardiovascular medication use. Individuals with greater carotid IMT displayed accelerated decline in performance over time on multiple tests of verbal and nonverbal memory, as well as a test of semantic association fluency and executive function. Carotid IMT predicts accelerated cognitive decline, particularly in the domain of memory, among community-dwelling individuals free of vascular and neurological disease. In a second study, we examined the relation between longitudinal trajectories of depressive symptoms as well as history of significant symptoms and subsequent carotid intimal medial thickness (IMT) among participants enrolled in the Baltimore Longitudinal Study of Aging. We also assessed longitudinal covariation of depressive symptoms and carotid IMT over two time points. Prior literature has identified inconsistent cross-sectional associations between depressive symptoms and carotid IMT in healthy persons, and existing longitudinal work has relied on depression assessment at a single time point. Our sample include 556 participants (303 women and 253 men), aged 20 to 93 years (mean +/- standard deviation = 55.8 +/- 15.9 years) who completed the Center for Epidemiological Studies-Depression (CES-D) scale from one to eight times over 1 to 15 years. These BLSA participants later underwent high-resolution B-mode ultrasonography to assess IMT of the far wall of the common carotid artery. A subset of these participants (n = 68) underwent reassessment of IMT an average of 3.9 years later. Linear and mixed-effects regression models were adjusted for sex, race, education, systolic blood pressure, low-density lipoprotein cholesterol, body mass index, diabetes, smoking, and antihypertensive, lipid-lowering, and antidepressant medications. We found no relation between trajectory of depressive symptoms or history of significant depressive symptoms and future carotid IMT. There was also no evidence for longitudinal covariation of depressive symptoms and IMT over time. Additional analyses similarly revealed a lack of significant associations. There is no association between depressive symptoms and carotid IMT in the present sample of healthy community-dwelling volunteers.