Associations of Serum Liver Function with Cerebral Blood Flow in Patients with Alzheimer's Disease.

Background: Increasing evidence suggests that both amyloid-ß metabolism disorders in the liver and cerebral hypoperfusion play an important role in the pathogenesis of Alzheimer's disease (AD). However, the relevance of liver function alterations to cerebral blood flow (CBF) of patients with AD remains unclear. Objective: We aimed to investigate the associations between liver function changes and CBF of patients with AD. Methods: We recruited 17 patients with sporadic AD. In addition to physical and neurological examinations, detection of AD biomarkers in cerebrospinal fluid by enzyme-linked immunosorbent assay and CBF assessment by arterial spin labeling sequence of magnetic resonance image scans as well as measure of liver function markers in serum by routine laboratory testing were conducted. Neuropsychological tests were evaluated, including Mini-Mental State Examination and Montreal Cognitive Assessment. Linear and rank correlations were performed to test the associations of liver function alterations with regional CBF of AD. Results: We found that liver function markers, especially total protein, the ratio of albumin to globin, globin, alkaline phosphatase, and aspartate aminotransferase were significantly associated with regional CBF of AD patients. Conclusions: These findings demonstrated significant associations between perfusion in certain brain regions of AD and alterations of liver function markers, particularly proteins and liver enzymes, which might provide implications to the pathogenesis and treatment of AD.

Associations of apolipoprotein E ε4 allele, regional cerebral blood flow, and serum liver function markers in patients with cognitive impairment.

Introduction: The ε4 allele of the apolipoprotein E gene (APOE4) is expressed abundantly in both the brain and peripheral circulation as a genetic risk factor for Alzheimer's disease (AD). Cerebral blood flow (CBF) dysfunction is an essential feature of AD, and the liver plays an important role in the pathogenesis of dementia. However, the associations of APOE4 with CBF and liver function markers in patients with cognitive impairment remains unclear. We aimed to evaluate the associations of APOE4 with CBF measured by arterial spin labeling (ASL) magnetic resonance imaging (MRI) and serum liver function markers in participants who were diagnosed with cognitive impairment. Methods: Fourteen participants with AD and sixteen with amnestic mild cognitive impairment (MCI) were recruited. In addition to providing comprehensive clinical information, all patients underwent laboratory tests and MRI. All participants were divided into carriers and noncarriers of the ε4 allele, and T-tests and Mann-Whitney U tests were used to observe the differences between APOE4 carriers and noncarriers in CBF and liver function markers. Results: Regarding regional cerebral blood flow (rCBF), APOE4 carriers showed hyperperfusion in the bilateral occipital cortex, bilateral thalamus, and left precuneus and hypoperfusion in the right lateral temporal cortex when compared with noncarriers. Regarding serum liver function markers, bilirubin levels (including total, direct, and indirect) were lower in APOE4 carriers than in noncarriers. Conclusion: APOE4 exerts a strong effect on CBF dysfunction by inheritance, representing a risk factor for AD. APOE4 may be related to bilirubin metabolism, potentially providing specific neural targets for the diagnosis and treatment of AD.