Background

Several neurodegenerative markers measured by magnetic resonance imaging (MRI) have shown to be related with frailty. While most studies have focused on surrogates of cerebral vascular damage such as increased white matter lesions, the associations between cortical atrophy and frailty were less often investigated.

Objectives

To investigate the cross-sectional and prospective associations between cortical thickness and frailty evolution in older adults.

Methods

We enrolled 484 community-dwelling adults aged ≥70 years, participants from the Multidomain Alzheimer Preventive Trial (MAPT), with data on cerebral cortical thickness and frailty. Cortical thickness was acquired by MRI for whole-brain and regional cortices. Two function-specific regions of interest, i.e., mobility-related regions and Alzheimer's disease (AD) signature, were selected on the basis of previous studies. Frailty status was assessed by the Fried frailty phenotype (i.e., weakness, slowness, involuntary weight loss, fatigue and low physical activity level) at baseline, after 6 months and every year until the end of the 5-year follow-up.

Results

Older adults with higher global cortical thickness were less likely to be pre-frail and frail at baseline (adjusted OR: 0.13, 95% CI: 0.03–0.65, p = 0.013). In addition, higher cortical thickness in mobility-related and AD-signature regions were associated with lower likelihood of being pre-frail and frail. Similar associations were observed for having weakness and slowness. However, neither global nor region-specific cortical thickness showed prospective associations with future frailty onset.

Conclusions

The global and regional cortical thickness cross-sectionally associated with frailty in older adults, but no prospective associations with incident frailty were found. The longitudinal relationship between cortical thickness and frailty evolution requires further investigation.

中文翻译：

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老年人大脑皮质厚度与虚弱之间的横断面和前瞻性关联。

背景

通过磁共振成像（MRI）测量的几种神经变性标记物已显示出与虚弱有关。尽管大多数研究都集中在替代脑血管损伤（如白质病变增加）的研究上，但皮质萎缩与虚弱之间的关联却很少被研究。

目标

调查老年人的皮质厚度和脆弱发展之间的横断面和前瞻性关联。

方法

我们从多领域阿尔茨海默氏症预防试验（MAPT）中招募了484位年龄≥70岁的社区居民，并提供了大脑皮层厚度和脆弱性的数据。通过MRI获取全脑和区域皮层的皮层厚度。在以前的研究的基础上，选择了两个感兴趣的功能特定的区域，即活动性相关区域和阿尔茨海默氏病（AD）签名。在基线，6个月后和每年直至5年随访结束时，通过Fried脆弱表型（即虚弱，缓慢，不自愿体重减轻，疲劳和低体力活动水平）评估脆弱状态。

结果

总体皮层厚度较高的老年人在基线之前较脆弱且较脆弱（校正后的OR：0.13，95％CI：0.03-0.65，p  = 0.013）。另外，在与流动性相关的区域和AD签名区域中较高的皮质厚度与预脆弱和脆弱的可能性较低相关。观察到类似的联想存在虚弱和缓慢。然而，无论是全球还是特定区域的皮层厚度均未显示与未来脆弱开始的前瞻性关联。

结论

在老年人中，整体和区域皮质厚度与衰弱相关，但未发现与衰弱相关的前瞻性关联。皮层厚度和脆弱发展之间的纵向关系需要进一步研究。