# Enlarged choroid plexus is linked with poorer physical function in rural older adults: a population-based study

## TL;DR

Larger choroid plexus volume in older adults is linked to worse physical function, particularly in women, and this is partly explained by brain ventricle and white matter changes.

## Contribution

This is the first population-based study to link enlarged choroid plexus with physical dysfunction in older adults, revealing sex-specific effects and mediating brain changes.

## Key findings

- Per 1-ml increase in choroid plexus volume was associated with a -0.24 decrease in physical performance scores.
- The association was stronger in women (-0.40) than in men (-0.17).
- Lateral ventricular and periventricular white matter hyperintensity volumes mediated 54.22% and 14.48% of the association, respectively.

## Abstract

The choroid plexus (ChP) plays an important role in producing cerebrospinal fluid (CSF) and physical dysfunction has been associated with alterations in CSF circulation. However, no population-based studies have thus far examined the association of ChP with physical function in older people.

This population-based cross-sectional study included 1217 participants (age ≥ 60 years; 57.35% women) in the MRI substudy of the Multimodal Interventions to delay Dementia and disability in rural China. ChP volume was automatically segmented using three-dimensional T1-weighted sequences. Physical function was assessed using the Short Physical Performance Battery (SPPB). Data were analyzed using general linear regression and mediation models.

Controlling for demographic characteristics, cardiovascular risk factors, stroke, disproportionately enlarged subarachnoid-space hydrocephalus (DESH), and total intracranial volume, per 1-ml increase in ChP volume was associated with β-coefficient of -0.24 (95% confidence interval: -0.37 to -0.11) for SPPB summary score, with the association being stronger in females (-0.40; -0.60 to -0.20) than in males (-0.17; -0.33 to -0.01) (p for ChP volume×sex interaction = 0.028). The associations were similar across three domains of balance, chair stand, and walking speed. In addition, enlarged ChP volume was associated with increased ventricular volume and white matter hyperintensity (WMH) volume. Mediation analysis suggested that lateral ventricular volume and periventricular WMH volume significantly mediated the association of ChP volume with the SPPB summary score, with the proportion of mediation being 54.22% and 14.48%, respectively.

Larger ChP volume is associated with poorer physical function in older adults, especially in women. The association is largely mediated by lateral ventricular and periventricular WMH volumes.

The online version contains supplementary material available at 10.1186/s12987-025-00642-z.