Homocysteine and asymmetric dimethylarginine concentrations in the plasma of Alzheimer’s disease patients with varying degrees of dementia

Alzheimer’s disease (AD) is accompanied by elevated levels of homocysteine (Hcy). Homocysteine may induce elevated concentration of asymmetric dimethylarginine (ADMA). Both Hcy and ADMA are the amino acids thought to represent risk factors of vascular diseases. Studies were conducted on the plasma levels of Hcy and methionine (Met), estimated by HPLC with electrochemical detection, as well as on levels of ADMA and arginine (Arg), estimated by HPLC with fluorescent detection, in the AD patients with benign through to severe dementia estimated by MMSE scale and in a control group. The studies disclosed elevated levels of Hcy and ADMA in AD (Hcy, p < 0.001) as compared to controls, as well as in subjects older than 60 years of age (Hcy, p < 0.01). The AD patients with severe dementia have shown elevated levels of Hcy (p < 0.05) as compared to the patients with moderate dementia. The concentration of Metand Arg showed a downward trend in AD patientswith severe dementia. The highest levels of ADMA have been demonstrated in AD patients in the early stages of the disease. In parallel, in AD with varying degrees of dementia and subjects older than 60 years of age a disturbed turnover was observed of Hcy to Met and of Arg to ADMA. Similarly to Hcy, ADMA seems to be a potential risk factor of AD and important factor for progress of dementia.