Homocysteine, antioxidant vitamins and lipids as biomarkers of neurodegeneration in Alzheimer's disease versus non-Alzheimer's dementia.

INTRODUCTION AND OBJECTIVE: Evidence for the benefit of antioxidants' based therapeutic intervention in dementia are inconsistent. Parallel studies in disease forms of dementia different than Alzheimer's are even less conclusive. In this study, the role of serum levels of homocysteine (tHcy), lipids and antioxidants in predicting the risk of cognitive decline in Alzheimer's disease (AD) versus non-Alzheimer's dementias (n-AD). The objective was to add to the ongoing cumulative research to establish the biochemical baseline for potential nutri-therapeutic intervention in different forms of dementia.

MATERIALS AND METHOD: 65 participants with dementia (DP-s) were divided into two groups: ADP--patients with Alzheimer's disease and n-ADP--patients with dementia of a different etiology than primary neurodegenerative dementia in the course of Alzheimer's disease. Cognitive function was assessed by Mini-Mental State Examination (MMSE) and related to plasma levels of tHcy, folate, vitamins B-6, B-12, lipids and vitamins A and E for both groups. Also examined were associations between cognitive impairment and several variables (age, education, duration of dementia) that might confound nutrition-cognition associations.

RESULTS: A significant reduction in serum vitamin A levels and elevation of total cholesterol levels were shown for the DP-s group compared to those in the control group. Moreover, significant differences were found in MMSE data and serum vitamin E and tHcy levels between patients with ADP and n-ADP. The scores for MMSE showed a correlation with the vitamin E levels and duration of dementia in the ADP group and/or correlation with tHcy, levels of vitamins A and/or E, and duration of dementia in the n-ADP group.

CONCLUSIONS: The results obtained suggest that elevated serum tHcy and decreased levels of vitamins A and E are associated with an increased risk of non-Alzheimer's dementias, although further studies involving a larger cohort are now needed to verify these results.