Association between physical frailty and cortical structure in middle-aged and elderly people: a Mendelian...

Area of Science:

• Neuroscience
• Genetics
• Aging Research

Background:

• Physical frailty is linked to brain structures, but the precise causes are unclear.
• Understanding this connection is crucial for aging and neurological health research.

Purpose of the Study:

• To investigate the potential causal relationship between physical frailty and cerebral cortical structure using Mendelian randomization.
• To identify specific cortical regions affected by frailty.

Main Methods:

• Genome-Wide Association Study (GWAS) data for frailty and cortical structure (surface area and thickness) were analyzed.
• Mendelian randomization (MR) analysis, including inverse variance weighting (IVW), MR-Egger, and weighted median, was employed.
• Sensitivity analyses using MR-PRESSO monitored for heterogeneity and outliers.

Main Results:

• No aggregate causal relationship was found between frailty and overall cortical thickness or surface area.
• Frailty showed a nominally significant association with the thickness of multiple specific cortical regions, including the middle temporal lobe, parahippocampus, and frontal lobe.
• Sensitivity analyses confirmed the reliability of these regional findings, with no significant heterogeneity or multidirectionality detected.

Conclusions:

• Physical frailty may have a causal influence on the thickness of specific brain cortical regions.
• Further research is needed to elucidate the exact mechanisms underlying this relationship and its clinical significance.