[P3–344]: Effect of Kidney Dysfunction on Cerebral Cortical Thinning in an Elderly Population

Abstract

Chronic kidney disease has been linked to cognitive impairment and morphological brain change. However, less is known about the impact of kidney functions on cerebral cortical thickness. This study investigated the relationship between kidney functions and global or lobar cerebral cortical thickness (CTh) in 259 non-demented elderly persons. Forty-three participants (16.7%) had kidney dysfunction, which was defined as either a glomerular filtration rate (GFR) of <60 ml/min/1.73 m 2 or presence of proteinuria. Kidney dysfunction was associated with lower global (β = −0.05, 95% CI = −0.08 to −0.01) as well as frontal, parietal, temporal, occipital, and insular lobar CTh. In the stratified analysis, the associations were more pronounced in women, APOEε4 non-carriers, and participants with a lower cognitive score. Besides, kidney dysfunction significantly increased the risk of cortical thinning, defined as being the lowest CTh tertile, in the insular lobe (adjusted odds ratio = 2.74, 95% CI = 1.31−5.74). Our results suggested that kidney dysfunction should be closely monitored and managed in elderly population to prevent neurodegeneration.The worldwide incidence and prevalence of dementia is increasing rapidly in persons of advanced age, which results in a huge global disease burden 1 . Currently, it is estimated that 46.8 million people worldwide are living with dementia, although in some developed countries the prevalence is gradually lowering possibly due to higher education levels and better control of cardiovascular risk factors 2, 3 . Long before clinically evident dementia-related functional impairment, generalized brain atrophy progresses gradually and asymptomatically with age, beginning at middle age 4 . Therefore, it is important to identify potentially preventable factors related to brain atrophy during the subclinical phase. Consequently, the structural neuroimaging, among various potential biomarkers for dementia, serves most closely temporal relationship with the onset of clinically detectable cognitive impairment 5 . The most commonly applied structural neuroimaging technique is magnetic resonance imaging (MRI). In various MRI imaging sequences, physicians can use three-dimensional T1-weighted images that clearly delineate the volume, shape, and thickness of the respective cerebral cortex. Specifically, the volume of cortical regions is a composite measure related to both thickness and surface area. In these two morphometric parameters, cortical thickness more closely reflects pathological changes related to dementia, such as laminar thinning and neuronal loss, while volume loss is largely the result of a reduction in surface area during normal aging 6 .Several factors have been linked to dementia, such as age, sex, education, apolipoprotein E (APOE) ε4 status, and various cardiovascular risk factors such as hypertension, diabetes mellitus, metabolic syndrome, and stroke 7 . In recent years, brain-kidney interaction is increasingly emphasized. Chronic kidney disease (CKD) and