Clinical Significance of Hyperhomocysteinemia Between Alzheimer's Disease and Vascular Dementia

ABSTRACT

BACKGROUND: Recent research has shown that risk factors for cerebrovascular disorders are also causes of dementia. Of these risk factors, hyperhomocysteinemia is well known to be positively correlated with all types of dementias including Alzheimer's disease (AD) and vascular dementia (VaD). But it is not know if there is a difference in the concentration of homocysteine in AD and VaD. We analyzed the homocysteine concentrations in AD and VaD and investigated the relationship between homocysteine and the progression of these two dementias. METHODS: A total of 193 patients to the dementia clinic at our hospital were enrolled. Fifty-four patients had AD and 48 patients had VaD. The remaining patients were the healthy control. Data for analysis consisted of the results of neuropsychological tests and homocysteine levels. RESULTS: Homocysteine levels were higher in AD and VaD patients than in healthy subjects, and no statistical difference was seen between AD and VaD. With lower mini-mental state examination scores, the homocysteine concentration increased significantly in VaD, but not in AD. The homocysteine concentration and the sum of box of clinical dementia rating were positively correlated in both AD and VaD. Other neuropsychological tests had no correlation with the homocysteine level. CONCLUSION: This study suggests that hyperhomocysteinemia, resulting in inflammation of vessel walls and oxidative stress, is a risk factor for both AD and VaD. However, our results did not clarify if hyperhomocysteinemia is related to the progression of dementia symptoms.