The Differences of Serum Homocysteine Levels in Mild Cognitive Impairment and Dementia of Alzheimer's Type with or without Depressive Symptoms

Hwangbo, Ram; Kim, Hyun; Lee, Kang Joon

Abstract

OBJECTIVES
Mild cognitive impairment(MCI) and dementia of Alzheimer's type(AD) are characterized by progressive decline of cognitive abilities and a wide range of neuropsychiatric symptoms like depression. Among various diagnostic tools of AD, many studies showed that elevated levels of serum total homocysteine are associated with increased risk of developing Alzheimer's disease, depression and other neuropsychiatric disorders. We investigated whether elevated homocysteine concentrations are associated with depressive symptoms in MCI and AD.
METHODS
A total of 86 patients diagnosed with MCI or AD participated. Total serum homocysteine levels in fasting blood samples were measured. We examined cognitive symptoms by MMSE-KC, Global Deterioration Scale(GDS), Clinical dementia rating(CDR) and depressive symptoms by Korean version of Geriatric Depression Scale(K-GDS).
RESULTS
The total serum homocysteine levels were significantly higher in MCI with depression than in MCI without depression. There was no significant difference in the mean homocysteine levels between AD patients with depression and AD patients without depression. The total homocysteine levels showed a negative correlation with MMSE-KC and a positive correlation with CDR, GDS.
CONCLUSIONS
These findings suggest that elevated homocysteine level is a risk factor for the decline of cognitive function and depression. We found a significant relationship between elevated serum homocysteine level and depressive symptoms in MCI. But our study had several limitations, thus more research is needed to confirm this finding.