12 April 2011
Homocysteine and its Role in Neurodegenerative Disorders
I stumbled across this article when doing some research for another course. I thought it was a relatively simple yet comprehensive article which addressed multiple components of disease that have been discussed in class (homocysteine levels, nutrient deficiency, etc.) in addition to corresponding with this weeks discussion of neurodegenerative disorders. Furthermore, upon reading this article, it brought to mind the discussion of stroke, which occurred at the beginning of the course. Increases homocysteine concentrations were directly correlated to an increase risk of stroke, which would subsequently exacerbate any cerebral vascular dysfunction experienced by the patient, causing further deleterious effects. As neurodegenerative diseases affect such a large group of people, and in my opinion impair one's quality of life, it would be amazing to decrease the severity of these diseases with something as accessible as a B-12 vitamin which can be found in any supermarket. However, it does appear that plasma homocysteine may not be a great indicator of a specific neurological disorder as it lacks specificity. In addition, use of homocysteine as a marker of disease my raise ethical questions, much like those discussed on Monday. Just though it was interesting! Note: While the abstract is listed below, the full article can be found at the provided link. Homocysteine: a biomarker in neurodegenerative diseases Abstract: Disease of the central nervous system are found in patients with severe hyperhomocysteinemia (HHcy). Epidemiological studies show a positive, dose dependent relationship between mild-to-moderate increases in plasma total homocysteine concentrations (Hcy) and the risk of neurodegenerative diseases such as Alzheimer's disease, vascular dementia, cognitive impairment or stroke. HHcy is a surrogate marker for B-vitamin deficiency (folate, B12, B6) and a neurotoxic agent. The concept of improving the patients clinical outcome by lowering of Hcy with B vitamins seems to be attractive. Recent B vitamin supplementation trials demonstrated a slowing of brain atrophy and improvement in some domains of cognitive function. Meta-analysis of secondary prevention trials showed that B vitamins supplementation caused a decrease in plasma Hcy and a trend for lowering the risk of stroke. HHcy is common in elderly people. Therefore, it seems prudent to identify B vitamin deficient subjects and to ensure sufficient vitamin intake. Therefore, recent evidence supports the role of Hcy as a potential biomarker in age-related neurodegenerative diseases. http://find.galegroup.com/gtx/retrieve.do?contentSet=IAC-Documents&resultListType=RESULT_LIST&qrySerId=Locale%28en%2C%2C%29%3AFQE%3D%28KE%2CNone%2C24%29Homocysteine+and+stroke+%24&sgHitCountType=None&inPS=true&sort=DateDescend&searchType=BasicSearchForm&tabID=T002&prodId=HRCA&searchId=R1¤tPosition=1&userGroupName=tusc83053&docId=A252447279&docType=IAC#
Subscribe to:
Post Comments (Atom)
Really interesting post, Alison! I've been doing a fair amount of research on Hcy as it relates to eNOS function, and endothelial dysfunction for another class. It's interesting to see the link between Hcy and neurodegeneration, as I tend to only think about it in regards to vascular disease. One paper I read stated that Hcy increases ADMA (which is a competetive inhibitor for eNOS against arginine, thus decreasing eNOS function). ADMA's effects seem to have more of a role in the small arterioles or the brain compared to larger arteries, like the carotid. That link got me thinking about what you just posted: maybe's Hcy in neuro disease is caused by ADMA's effects as well. Unfortunately, the studies in vascular disease haven't been too promising regarding B vitamin supplementation, but maybe a secondary analysis can be run on some of those large studies in order to see if those who were in the treatment group observe benefits as far as cerebral health is concerned.
ReplyDelete