Brain Iron in signature regions relating to cognitive aging in older adults: the Taizhou Imaging Study

• Published in: Alzheimer's research & therapy 2024-10, Vol.16 (1), p.211-13, Article 211
• Main Authors: Li, Rui, Fan, Yi-Ren, Wang, Ying-Zhe, Lu, He-Yang, Li, Pei-Xi, Dong, Qiang, Jiang, Yan-Feng, Chen, Xing-Dong, Cui, Mei
• Format: Article
• Language: English
• Subjects: AD signature; Advertising executives; Aged; Aging; Aging - pathology; Aging-specific signature; Alzheimer's disease; Atrophy; Atrophy - pathology; Brain; Brain - diagnostic imaging; Brain - metabolism; Brain - pathology; Brain research; China; Cognition; Cognitive Aging - physiology; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - metabolism; Cortical thickness; Female; Gerontology; Health aspects; Humans; Iron; Iron - metabolism; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Methods; Middle Aged; Neuropsychological Tests; Physiological aspects
• ISSN: 1758-9193; 1758-9193
• DOI: 10.1186/s13195-024-01575-9

Recent magnetic resonance imaging (MRI) studies have established that brain iron accumulation might accelerate cognitive decline in Alzheimer's disease (AD) patients. Both normal aging and AD are associated with cerebral atrophy in specific regions. However, no studies have investigated aging- and AD-selective iron deposition-related cognitive changes during normal aging. Here, we applied quantitative susceptibility mapping (QSM) to detect iron levels in cortical signature regions and assessed the relationships among iron, atrophy, and cognitive changes in older adults. In this Taizhou Imaging Study, 770 older adults (mean age 62.0 ± 4.93 years, 57.5% women) underwent brain MRI to measure brain iron and atrophy, of whom 219 underwent neuropsychological tests nearly every 12 months for up to a mean follow-up of 2.68 years. Global cognition was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Domain-specific cognitive scores were obtained from MoCA subscore components. Regional analyses were performed for cortical regions and 2 signature regions where atrophy affected by aging and AD only: Aging (AG) -specific and AD signature meta-ROIs. The QSM and cortical morphometry means of the above ROIs were also computed. Significant associations were found between QSM levels and cognitive scores. In particular, after adjusting for cortical thickness of regions of interest (ROIs), participants in the upper tertile of the cortical and AG-specific signature QSM exhibited worse ZMMSE than did those in the lower tertile [ = -0.104, p = 0.026; = -0.118, p = 0.021, respectively]. Longitudinal analysis suggested that QSM values in all ROIs might predict decline in ZMoCA and key domains such as attention and visuospatial function (all p