Association between liver dysfunction and Alzheimer's disease found in new study
A newstudy is building on the growing association between theliver and Alzheimer's disease. Suggesting a correlation betweenblood-based liver function biomarkers and several neurological signsof Alzheimer's, the research hypothesizes the neurodegenerativedisease has broader metabolic effects in organs otherthan the brain.
Several studies published over the past few years have foundintriguing connections between Alzheimer's disease and the liver. Just last year it was suggested that an age-related decline inplasmalogens, a class of lipids produced by the liver, could berelated to an increased risk of Alzheimer's. Other studies havepreviously found certain enzymes produced by the liver can conferneuroprotective effects, implying a dysfunctional liver can possiblyprecede the onset of neurodegenerative diseases such as Alzheimer's.
"While we have focused for too long on studying the brain inisolation, we now have to study the brain as an organ that iscommunicating with and connected to other organs that support itsfunction and that can contribute to its dysfunction," explains RimaKaddurah-Daouk, from Duke University, and one of the lead researcherson the new study. "The concept emerges that Alzheimer's diseasemight be a systemic disease that affects several organs including theliver."
The new study set out to fill a gap in the current body ofscientific knowledge, looking to uncover any potential associationbetween liver function biomarkers and Alzheimer's biomarkers. Acohort of more than 1,500 subjects was studied, including around 400healthy controls. Several Alzheimer's biomarkers were tracked,including amyloid and tau levels in cerebrospinal fluid, against fivestandard liver-function markers easily detected in blood samples.
The results revealed a consistent association between alterationsin liver function and the progression of Alzheimer's markers. Theresearchers are cautious to note that it is unclear at this stagewhether these liver function alterations are playing a causative rolein the progression of Alzheimer's. While prior research hasdescribed more overtly how the liver could be directly influencingneurodegeneration, this study more generally suggests aninteresting "axis of communication" between the liver and the brain.
At the very least the study hypothesizes these liver functionbiomarkers, easily tracked through regular blood testing, could offerclinicians new ways to identify patients at a higher risk ofdeveloping Alzheimer's. Kwangsik Nho, a radiologist from the Indiana University School of Medicine working on thenew study, also suggeststhis novel brain-liver association points to new ways to understandhow Alzheimer's may have broad systemic signs outside of just thebrain.
"This is a new paradigm for Alzheimer's research," says Nho."Until now, we only focused on the brain. Our research shows thatby using blood biomarkers, we can still focus on the brain but alsofind evidence of Alzheimer's and improve our understanding of thebody's internal signalling."
The new research was published in the journal JAMA Network Open.
Source: IU School of Medicine