Association of white matter lesions and brain atrophy with the development of dementia in a community: the Hisayama Study

• Published in: Psychiatry and clinical neurosciences 2023-06, Vol.77 (6), p.330-337
• Main Authors: Nakazawa, Taro, Ohara, Tomoyuki, Hirabayashi, Naoki, Furuta, Yoshihiko, Hata, Jun, Shibata, Mao, Honda, Takanori, Kitazono, Takanari, Nakao, Tomohiro, Ninomiya, Toshiharu
• Format: Article
• Language: English
• Subjects: Alzheimer disease; Atrophy; Atrophy - pathology; Brain - diagnostic imaging; Brain - pathology; Cardiovascular diseases; Cardiovascular system; cerebral small vessel diseases; Dementia; Dementia disorders; Gray Matter - diagnostic imaging; Gray Matter - pathology; Humans; Lesions; leukoencephalopathies; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Morphometry; Neurodegenerative Diseases - pathology; Neuroimaging; Regular; Risk factors; Substantia alba; Substantia grisea; Vascular; White Matter - diagnostic imaging; White Matter - pathology
• ISSN: 1323-1316; 1440-1819; 1440-1819
• DOI: 10.1111/pcn.13533

Aim To investigate the association of white matter lesions volume (WMLV) levels with dementia risk and the association between dementia risk and the combined measures of WMLV and either total brain atrophy or dementia‐related gray matter atrophy in a general older population. Methods One thousand one hundred fifty‐eight Japanese dementia‐free community‐residents aged ≥65 years who underwent brain magnetic resonance imaging were followed for 5.0 years. WMLV were segmented using the Lesion Segmentation Toolbox. Total brain volume (TBV) and regional gray matter volume were estimated by voxel‐based morphometry. The WMLV‐to‐intracranial brain volume ratio (WMLV/ICV) was calculated, and its association with dementia risk was estimated using Cox proportional hazard models. Total brain atrophy, defined as the TBV‐to‐ICV ratio (TBV/ICV), and dementia‐related regional brain atrophy defined based on our previous report were calculated. The association between dementia risk and the combined measures of WMLV/ICV and either total brain atrophy or the number of atrophied regions was also tested. Results During the follow‐up, 113 participants developed dementia. The risks of dementia increased significantly with higher WMLV/ICV levels. In addition, dementia risk increased additively both in participants with higher WMLV/ICV levels and lower TBV/ICV levels and in those with higher WMLV/ICV levels and a higher number of dementia‐related brain regional atrophy. Conclusion The risk of dementia increased significantly with higher WMLV/ICV levels. An additive increment in dementia risk was observed with higher WMLV/ICV levels and lower TBV/ICV levels or a higher number of dementia‐related brain regional atrophy, suggesting the importance of prevention or control of cardiovascular risk factors.