Hippocampal volume is an important biomarker of Alzheimer's disease (AD), and genetic risk of AD is associated with hippocampal atrophy. However, the hippocampus is not a uniform structure and has a number of subfields, the associations of which with age, sex, and polygenic risk score for AD (PRSAD) have been inadequately investigated. We examined these associations in 17,161 cognitively normal UK Biobank participants (44-80 years). Age was negatively associated with all the hippocampal subfield volumes and females had smaller volumes than men. Higher PRSAD was associated with lower volumes in the bilateral whole hippocampus, hippocampal-amygdala-transition-area, and hippocampal tail; right subiculum; left cornu ammonis 1, cornu ammonis 4, molecular layer, and granule cell layer of dentate gyrus. Older individuals (median age 63 years, n = 8984) showed greater subfield vulnerability to high PRSAD compared to the younger group (n = 8177), but the effect did not differ by sex. The pattern of subfield involvement in relation to the PRSAD in community dwelling healthy individuals sheds additional light on the pathogenesis of AD.

中文翻译：

---

17,161 名英国生物银行参与者的阿尔茨海默病多基因风险评分与海马亚区体积之间的关联

海马体积是阿尔茨海默病（AD）的重要生物标志物，AD的遗传风险与海马萎缩有关。然而，海马体并不是一个统一的结构，并且有许多子域，这些子域与年龄、性别和 AD 多基因风险评分 (PRSAD) 的关联尚未得到充分研究。我们在 17,161 名认知正常的英国生物银行参与者（44-80 岁）中检查了这些关联。年龄与所有海马亚区体积呈负相关，女性的体积小于男性。较高的 PRSAD 与双侧全海马、海马-杏仁核-过渡区和海马尾的体积较低有关；右下突；左角1、角4、分子层、齿状回颗粒细胞层。老年人（中位年龄 63 岁，n = 8984) 与年轻组 (n = 8177) 相比，对高 PRSAD 的亚场易感性更强，但这种影响没有性别差异。在社区居住的健康个体中，与 PRSAD 相关的子领域参与模式为 AD 的发病机制提供了额外的启示。