Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania.
Department of Environmental and Occupational Health, School of Public Health, University of Nevada Las Vegas.
J Gerontol B Psychol Sci Soc Sci. 2021 Jun 14;76(6):1027-1035. doi: 10.1093/geronb/gbaa173.
Social engagement (SE) may protect against cognitive decline in older adults. We estimate associations of SE with gray matter (GM) microstructure in regions of interest (ROI) relevant to social cognition, among community-dwelling older adults.
Cross-sectional analysis of 293 Health ABC study participants who underwent 3 Tesla magnetic resonance imaging with diffusion tensor and free from cognitive impairment was conducted. Linear regression models tested associations between SE index (marital status, not living alone, social activities, work, and volunteering) and mean diffusivity (MD) of GM ROIs, adjusted for age, race, gender, and education. Hearing and activities of daily living (ADL) difficulties were tested as confounders. Effect modification by gender was tested with interaction terms and stratification by gender.
Higher SE was significantly related to lower MD (greater GM microstructural integrity) (shown as standardized estimate [p-value]) in left middle frontal gyrus-orbital part: -.168 (.005), left caudate nucleus: -.141 (.02), left temporal pole-middle temporal gyrus: -.136 (.03), right middle frontal gyrus: -.160 (.006), right superior frontal gyrus-orbital part: -.187 (.002), and right middle frontal gyrus-orbital part: -.124 (.04), when adjusted for demographic attributes. Associations were robust to adjustments for hearing or ADL difficulty. There was significant effect modification by gender for some ROIs, with associations only for females.
SE is related to greater microstructural integrity of specific GM regions relevant to social cognition, that have described roles in dementia. SE may therefore be a useful preventive mechanism against loss of GM integrity in older adults.
社交参与（SE）可能有助于预防老年人认知能力下降。我们估计，在社区居住的老年人中，SE 与与社会认知相关的感兴趣区域（ROI）的灰质（GM）微观结构之间存在关联。
对 293 名健康 ABC 研究参与者进行了横断面分析，这些参与者接受了 3T 磁共振成像，包括弥散张量成像，且无认知障碍。线性回归模型测试了 SE 指数（婚姻状况、不独居、社交活动、工作和志愿服务）与 GM ROI 平均弥散度（MD）之间的关联，调整了年龄、种族、性别和教育。听力和日常生活活动（ADL）困难被测试为混杂因素。通过交互项和性别分层测试性别对效应的修饰作用。
更高的 SE 与左额中回眶部（MD 值更低，GM 微观结构完整性更高）呈显著相关：-.168（.005），左尾状核：-.141（.02），左颞极-中颞回：-.136（.03），右额中回：-.160（.006），右额上回眶部：-.187（.002），右额中回眶部：-.124（.04），在调整了人口统计学属性后。这些关联在调整听力或 ADL 困难后仍然稳健。一些 ROI 存在显著的性别效应修饰作用，仅在女性中存在关联。
SE 与与社会认知相关的特定 GM 区域的微观结构完整性有关，这些区域在痴呆症中具有描述性作用。因此，SE 可能是预防老年人 GM 完整性丧失的有用机制。
