[Influence of vascular comorbidities on the antioxidant                     defense system in Alzheimer's disease].
OBJECTIVE
Oxidative stress is a critical factor in the pathophysiology of dementia, but the role of oxidant/antioxidant imbalance in relation to vascular pathology in the onset and progression of Alzheimer's disease (AD) is poorly understood. The aim of this study was the identification of an association between vascular comorbidities/vascular risk factors and plasma levels of antioxidant micronutrients in patients with AD.


METHODS
41 patients with AD  and 34 controls were included in the study. Atherosclerosis (increased intima-media thickness of the common carotid artery) and/or type 2 diabetes mellitus were diagnosed in 21 AD  patients (AD  Plus group). 20 patients with AD were free of vascular comorbidities and risk factors (AD group). A neuropsychological assessment (Mini-Mental State Examination, MMSE; Clock drawing test; DemTect) and the measurement of plasma levels of lipophilic micronutrients including retinol (vitamin A), α-tocopherol (vitamin E), lutein, zeaxanthin, β-cryptoxanthin, lycopene, α-carotene and β-carotene by HPLC were performed in all study subjects.


RESULTS
Plasma levels of retinol, vitamin E, lutein, zeaxanthin, lycopene and β-carotene were significantly lower in the AD  Plus group than in controls. Furthermore, vitamin A levels were correlated with MMSE scores and the levels of vitamin E, lutein, zeaxanthin and lycopene were correlated with all neuropsychological tests.


CONCLUSIONS
The depletion of circulating antioxidant micronutrients observed in AD  patients is associated with vascular comorbidities and risk factors. The vascular comorbidities of patients with AD should also be identified in light of the presence and degree of depletion of the antioxidant defense system of the organism. This might lead to a better lifestyle-related counselling of patients with AD  and their caregivers, with possible positive preventive effects on worsening in the long run. Further studies with a larger patient sample are needed to verify the negative effect of vascular pathology in AD-related oxidative stress.
Klinik für Altersmedizin und Frührehabilitation, Medizinische Fakultät der Ruhr-Universität Bochum, Marienhospital Herne. polidori@uni-duesseldorf.de
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D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000150:complications* / Q000503:physiopathology; D000975:Antioxidants / Q000032:analysis*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D018977:Micronutrients / Q000097:blood*; D009483:Neuropsychological Tests; D018384:Oxidative Stress / Q000502:physiology; D012307:Risk Factors; D014652:Vascular Diseases / Q000097:blood* / Q000150:complications*; D014801:Vitamin A / Q000097:blood
D000975:Antioxidants; D018977:Micronutrients; D014801:Vitamin A