Higher blood levels of homocysteine (HCY), an amino acid in the body, may be associated with changes in deep brain tissue in middle-aged men, according to an article in the September issue of The Archives of Neurology, one of the JAMA/Archives journals.
According to the article, high HCY levels have been associated with an increased risk for vascular diseases, and some studies have suggested that HCY may also increase the risk for brain atrophy and Alzheimer disease. Other studies have shown an inverse relationship between elevated HCY levels and cognitive functioning, the article states.
Perminder Sachdev, M.D., Ph.D., F.R.A.N.Z.C.P., of the University of New South Wales, Sydney, Australia, and colleagues examined the relationship between HCY levels and findings from brain magnetic resonance imaging (MRI) and cognitive function among healthy individuals aged 60 to 64 years old. There were 196 men and 189 women included in the study.
Blood samples from each participant were used to measure HCY levels. Participants also had MRI of their brains and underwent a battery of cognitive tests administered within three months of the MRI and blood examinations.
The researchers found that HCY levels did not have a significant relationship with brain atrophy, but high HCY levels in men were related to changes in deep white matter hyperintensities in the brain, which appeared on the MRI.
“Total HCY level is independently related to leukoaraiosis [deep white matter hyperintensities] in middle-aged men, and this may be functionally relevant in the form of mild cognitive impairment,” write the authors.
“Contrary to expectation and based on our finding in a previous study involving somewhat older individuals, tHCY [total HCY] levels did not relate with brain atrophy,” the researchers write. “The subjects in our current study were younger than in the previously reported studies, and it is possible that the effect of tHCY levels on brain structure does not manifest until later in life, possibly at age 70 years and older.”