The hypothalamus regulates homeostasis across the lifespan and is emerging as a regulator of aging. In murine models, aging-related changes in the hypothalamus, including microinflammation and gliosis, promote accelerated neurocognitive decline. We investigated relationships between hypothalamic microstructure and features of neurocognitive aging, including cortical thickness and cognition, in a cohort of community-dwelling older adults (age range 65–97 years, n=124). Hypothalamic microstructure was evaluated with two magnetic resonance imaging diffusion metrics: mean diffusivity (MD) and fractional anisotropy (FA), using a novel image processing pipeline. Hypothalamic MD was cross-sectionally positively associated with age and it was negatively associated with cortical thickness. Hypothalamic FA, independent of cortical thickness, was cross-sectionally positively associated with neurocognitive scores. An exploratory analysis of longitudinal neurocognitive performance suggested that lower hypothalamic FA may predict cognitive decline. No associations between hypothalamic MD, age, and cortical thickness were identified in a younger control cohort (age range 18–63 years, n=99). To our knowledge, this is the first study to demonstrate that hypothalamic microstructure is associated with features of neurocognitive aging in humans.

中文翻译：

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下丘脑 MRI 衍生的微观结构与人类神经认知衰老相关


下丘脑在整个生命周期中调节体内平衡，并逐渐成为衰老的调节器。在小鼠模型中，下丘脑的衰老相关变化，包括微炎症和神经胶质增生，会加速神经认知能力的下降。我们在一群社区老年人（年龄范围 65-97 岁，n=124）中研究了下丘脑微观结构与神经认知衰老特征（包括皮质厚度和认知）之间的关系。使用新颖的图像处理流程，通过两种磁共振成像扩散指标来评估下丘脑微观结构：平均扩散率（MD）和分数各向异性（FA）。下丘脑 MD 与年龄呈横断面正相关，与皮质厚度呈负相关。下丘脑 FA 与皮质厚度无关，与神经认知评分呈横断面正相关。对纵向神经认知表现的探索性分析表明，下丘脑 FA 较低可能预测认知能力下降。在较年轻的对照队列（年龄范围 18-63 岁，n=99）中未发现下丘脑 MD、年龄和皮质厚度之间存在关联。据我们所知，这是第一项证明下丘脑微观结构与人类神经认知衰老特征相关的研究。