Subclinical Atherosclerosis, Vascular Risk Factors, and White Matter Alterations in Diffusion Tensor Imaging Findings of Older Adults With Cardiometabolic Diseases.

Yoshiaki Tamura,Yuko Chiba,Shugo Zen,Hisae Takahashi,Aya Tachibana,Kenji Toyoshima,Yoshinori Matsuo,Joji Ishikawa,Takuya Omura,Remi Kodera,Kazuhito Oba,Aya M Tokumaru,Atsushi Araki,So Watanabe,Keigo Shimoji

doi:10.3389/fnagi.2021.712385

Yoshiaki Tamura, Yuko Chiba + Show 13 more

Open Access

https://doi.org/10.3389/fnagi.2021.712385

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Abstract

White matter abnormalities may reflect cerebral microvessel disease. Diffusion tensor imaging (DTI) can help detect early changes in white matter integrity in each tract. However, studies investigating the relationship between subclinical atherosclerosis markers and white matter alterations in DTI findings are limited. This study aimed to examine associations between cardiovascular risk factors and indices of subclinical atherosclerosis—ankle brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and carotid artery intima-media thickness (IMT)—and altered white matter integrity in older patients. A total of 224 patients (aged ≥65 years) with cardiometabolic disease who underwent magnetic resonance imaging (MRI) and either plethysmography or cervical ultrasound at the start of the 3-year observational study period were included in this study. We measured fractional anisotropy (FA) and mean diffusivity (MD), which are indices of white matter integrity in seven white matter tracts. In a univariate analysis, lower ABI and higher baPWV values were associated with FA or MD abnormalities in several tracts, whereas IMT was scarcely associated with such change. In addition, high blood pressure and glycoalbumin/glycohemoglobin ratio (GA/HbA1c) and low body mass index (BMI) and triglyceride (TG) levels were associated with FA or MD abnormalities. In a multivariate analysis adjusted for age, sex, BMI, diastolic blood pressure, TG, and GA/HbA1c, the associations between ABI and FA or MD remained in all of either side of the following tracts: anterior thalamic radiation, forceps minor, inferior frontooccipital fasciculus (p < 0.001 for all) and superior longitudinal fasciculus (SLF; p < 0.05), whereas most of those between baPWV and FA or MD disappeared except for SLF (p < 0.05). These results indicate that low ABI could be an indicator of white matter abnormalities.

Highlights

White matter fibers are susceptible to ischemia; white matter hyperintensity (WMH) in fluid-attenuated inversion recovery (FLAIR) images on magnetic resonance imaging (MRI) scans represent ischemic changes in cerebral microvessels (Matsusue et al, 2006)
We have previously reported findings from a cross-sectional study, showing that abnormalities of white matter integrity in the left anterior thalamic radiation (ATR) and right inferior frontooccipital fasciculus (IFOF) are associated with sarcopenia and its correlates (Tamura et al, 2021)
In this study, we investigated whether multiple indices of subclinical atherosclerosis (ABI, carotid artery intima-media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV)) or cardiovascular risk factors are associated with changes in Diffusion tensor imaging (DTI) values of the white matter tracts in older patients with cardiometabolic diseases

Summary

Introduction

White matter fibers are susceptible to ischemia; white matter hyperintensity (WMH) in fluid-attenuated inversion recovery (FLAIR) images on magnetic resonance imaging (MRI) scans represent ischemic changes in cerebral microvessels (Matsusue et al, 2006). DTI is a technique in which multipledirectional diffusion-weighted MRI images are reconstructed, and fractional anisotropy (FA, alterations of anisotropy) or mean diffusivity (MD, diffusivity of water molecule) values are used as indices of damage to the white matter. This method has several advantages: it can detect slight alterations in the white matter earlier than conventional MRI imaging, and it can detect these alterations separately in each tract (Assaf and Pasternak, 2008), allowing for the correlation of the damage observed in particular tracts with disease presentation and progression. We have previously reported findings from a cross-sectional study, showing that abnormalities of white matter integrity in the left anterior thalamic radiation (ATR) and right inferior frontooccipital fasciculus (IFOF) are associated with sarcopenia and its correlates (Tamura et al, 2021)

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