Alzheimer's disease and cholesterol
"Bad cholesterol" may be the cause of early Alzheimer's disease
Dmitry Kolesnik, Copper News
Researchers from the Veterans Affairs Medical Center in Atlanta and Emory University have found a link between high levels of LDL (low–density lipoproteins - "bad" cholesterol) and early Alzheimer's disease. The results of the study are published in JAMA Neurology (Association of Early-Onset Alzheimer's Disease With Elevated Low-density Lipoprotein Cholesterol Levels and Rare Genetic Coding Variants of APOB).
"One interpretation of our current data is that LDL plays a causal role. If this is the case, we may need to revise the low-density cholesterol targets to help reduce the risk of developing Alzheimer's disease. Our work is now focused on checking the presence of a causal relationship," he said Thomas Wingo, lead author of the study.
Elevated cholesterol levels are associated with an increased risk of developing Alzheimer's disease in old age. Previous studies have shown that the main risk factor for Alzheimer's disease is a specific mutation in the APOE gene (apolipoprotein E). As is known, the ApoE E4 variant increases the level of circulating cholesterol, especially LDL. This type of cholesterol is called "bad" because its high level leads to the development of atherosclerosis and narrowing of the arteries.
Early onset of Alzheimer's disease (before age 65) it is relatively rare – about 10 percent of all cases. According to past studies, this condition is largely due to genetics, that is, it can be inherited from parents. As it is known today, in addition to AOE E4, three specific gene variants are associated with early Alzheimer's disease – ARP (beta-amyloid precursor – PBA), PSEN1 and PSEN2 (presenelin1 and presenelin2). However, these gene variants explain only about 10 percent of cases.
The researchers sequenced specific regions of the genome in 2125 people (654 with early onset of Alzheimer's disease, and 1471 – a control group). They also tested blood samples from 267 participants to measure LDL cholesterol.
Scientists have found that APOE E4 explains about 10 percent of cases of early onset of Alzheimer's disease. About 3 percent of cases are associated with at least one of the known risk factors – APP, PSEN1 and PSEN2.
Testing of blood samples showed that participants with elevated LDL levels were more likely to have early-onset Alzheimer's disease compared to patients with normal cholesterol levels (even after taking into account the potential effects of the APOE E4 mutation). Therefore, cholesterol may be an independent risk factor.
No association was found between the level of HDL (high–density lipoproteins - "good" cholesterol) and the early onset of Alzheimer's disease; and the association between the disease and triglyceride levels was very weak.
Scientists have also identified a new possible genetic risk factor for early Alzheimer's disease – a rare variant of the gene called APOB (apolipoprotein B). This gene encodes a protein involved in the metabolism of lipids or fats, including cholesterol.
The study sheds light on possible risk factors for early onset of Alzheimer's disease, but more research is needed to fully explain the link between the disease and cholesterol.
Portal "Eternal youth" http://vechnayamolodost.ru