College of Health Solutions, Speech and Hearing Sciences, Arizona State University, Tempe, Arizona, USA.
Banner Alzheimer's Institute, Phoenix, Arizona, USA.
Autism Res. 2022 Oct;15(10):1810-1823. doi: 10.1002/aur.2797. Epub 2022 Aug 24.
Research studying aging in adults with autism spectrum disorder (ASD) is growing, but longitudinal work is needed. Autistic adults have increased risk of dementia, altered hippocampal volumes and fornix integrity, and verbal memory difficulties compared with neurotypical (NT) adults. This study examined longitudinal aging in middle-age adults with ASD versus a matched NT group, and compared findings with cross-sectional age effects across a broad adult age range. Participants were 194 adults with (n = 106; 74 male) and without (n = 88; 52 male) ASD, ages 18-71. Participants (n = 45; 40-70 age range) with two visits (2-3 years apart) were included in a longitudinal analysis. Hippocampal volume, fornix fractional anisotropy (FA), and verbal memory were measured via T1-weighted MRI, diffusion tensor imaging, and the Rey Auditory Verbal Learning Test, respectively. Longitudinal mixed models were used for hippocampal system variables and reliable change index categories were used for Auditory Verbal Learning Test analyses. Multivariate regression was used for cross-sectional analyses. Middle-age adults with ASD had greater longitudinal hippocampal volume loss and were more likely to show clinically meaningful decline in short-term memory, compared with NT. In contrast, cross-sectional associations between increasing age and worsening short-term memory were identified in NT, but not autistic adults. Reduced fornix FA and long-term memory in ASD were found across the broad cross-sectional age range. These preliminary longitudinal findings suggest accelerated hippocampal volume loss in ASD and slightly higher rates of clinically-meaningful decline in verbal short-term memory. Contradictory cross-sectional and longitudinal results underscore the importance of longitudinal aging research in autistic adults. LAY SUMMARY: Autistic adults have increased risk of dementia, differences in brain memory structures, and difficulty with memory compared with neurotypical (NT) adults. However, there are no publications that follow the same middle-age autistic adults over time to see how their brain and memory change. Our preliminary findings in a small middle-age autism sample suggest a key memory brain structure, the hippocampus, may shrink faster over 2-3 years compared with NT, and short-term memory may become more challenging for some. Across a broad adult range, autistic adults also had reduced integrity of connections to the hippocampus and greater challenges with long-term memory. In our larger sample across a broad age range, the results did not hint at this aforementioned pattern of accelerated aging. This underscores the importance of more aging research in autism, and especially research where people are followed over time.
研究表明，自闭症谱系障碍（ASD）成人的衰老研究正在不断增加，但仍需要进行纵向研究。与神经典型（NT）成人相比，自闭症成人痴呆风险增加，海马体体积和穹窿完整性以及言语记忆能力下降。本研究比较了中年自闭症成人与匹配的 NT 组的纵向衰老情况，并与广泛的成年年龄范围内的横断面年龄效应进行了比较。参与者包括 194 名患有 ASD 的成年人（n=106；74 名男性）和无 ASD 的成年人（n=88；52 名男性），年龄在 18-71 岁之间。有两次就诊（相隔 2-3 年）的 45 名参与者（40-70 岁年龄范围）被纳入纵向分析。通过 T1 加权 MRI、弥散张量成像和 Rey 听觉言语学习测试分别测量海马体体积、穹窿分数各向异性（FA）和言语记忆。使用纵向混合模型进行海马体系统变量分析，使用听觉言语学习测试可靠变化指数类别进行分析。使用多元回归进行横断面分析。与 NT 相比，中年自闭症成人的海马体体积损失更大，更有可能出现短期记忆的临床意义上的下降。相比之下，在 NT 中发现了与年龄增长和短期记忆恶化相关的横断面关联，但在自闭症成人中则没有。在广泛的横断面年龄范围内发现了自闭症成人穹窿 FA 减少和长期记忆受损。这些初步的纵向研究结果表明，ASD 中存在加速的海马体体积损失，言语短期记忆的临床意义下降速度略高。相反的横断面和纵向结果突显了对自闭症成人进行纵向衰老研究的重要性。
