Supplementary Material for: Determinants of brain ageing in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): study design, neuroimaging protocol, and baseline characteristics

Aim: To describe the design, the neuroimaging protocol as well as the baseline characteristics of the participants from Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), which will be part of an extensive investigation of the determinants of brain ageing based on high-resolution neuroimaging 3T (tesla) and 7T magnetic resonance imaging (MRI) conceptualized by the Ageing and Brain Working Study Group from ELSA-Brasil. Methods: A representative sample of 2,165 participants (mean age = 60.3 (9.9) years, 55.5 % female) for further neuroimaging and study with the protocol described here was selected from ELSA-Brasil. The criteria used for selection into this protocol were cognitive status and age in Wave 3 (2017-2019), and participants were split into two subsamples: 1) A randomized sample of participants with +1, n=215)] and 2) All participants with ≥ 70 years at Wave 3 classified as Superagers cases (n=171) and their matched controls (n=324) based on delayed memory ( Wave 3). Both samples will be scanned using a 3T MRI, and an additional 7T MRI exam will be conducted in the Superagers study to further evaluate brain connectivity. An extensive dataset of sociodemographic, lifestyle, cognitive, mental health, frailty, and other laboratory and clinical exams collected since the baseline of the main study will be considered as predictors of structural and functional patterns of brain aging. The main characteristics of participants and the MRI protocol are described here. Results: Among those under 70 years, the above-average group for cognition showed better cognitive and mental health scores than the other groups (most p-values < 0.001). Considering the elderly who were 70 years or older, Superagers showed higher scores for delayed recall memory, better global cognition, and verbal fluency than Controls at Wave 3 (all p-values < 0.001). Conclusions: The ELSA-Brasil study will be a unique opportunity to unravel the determinants of brain aging in an admixed sample in Latin America.研究目的：本研究旨在描述巴西成人健康纵向研究（Brazilian Longitudinal Study of Adult Health, ELSA-Brasil）中受试者的研究设计、神经影像方案及基线特征。该研究是ELSA-Brasil衰老与脑研究工作组发起的一项针对脑衰老决定因素的综合调查的组成部分，此项调查基于高分辨率3特斯拉（tesla）和7特斯拉磁共振成像（magnetic resonance imaging, MRI）技术开展。研究方法：从ELSA-Brasil队列中选取具有代表性的2165名受试者（平均年龄60.3±9.9岁，女性占比55.5%），开展本项神经影像研究。本方案的入选标准为第三轮调查（2017-2019年）时的认知状态与年龄，受试者被分为两个亚组：1）认知水平高于平均的随机抽样受试者（n=215）；2）第三轮调查时年龄≥70岁的超级衰老者（Superagers）亚组，包含171名超级衰老者及基于第三轮调查延迟记忆指标匹配的324名对照受试者。两组受试者均接受3T磁共振成像扫描，其中超级衰老者亚组额外接受7T磁共振成像检查，以进一步评估脑连接模式。本研究将纳入自主研究基线以来收集的社会人口学特征、生活方式、认知功能、心理健康状态、衰弱程度及其他实验室与临床检查的多维度数据，作为脑衰老结构与功能模式的预测因子。本文详述了受试者的核心特征及磁共振成像方案。研究结果：在70岁以下的受试者中，认知水平高于平均的组别相较于其余组别，认知与心理健康评分均更优异（多数p值<0.001）。针对70岁及以上的老年受试者，超级衰老者在第三轮调查中的延迟回忆记忆、整体认知及言语流畅性评分均显著高于对照组（所有p值<0.001）。研究结论：本项基于ELSA-Brasil队列的研究将为揭示拉丁美洲混血人群脑衰老的决定因素提供独一无二的研究契机。