Altered plasma antioxidant status in subjects with Alzheimer's disease and vascular dementia.
OBJECTIVE
Oxygen-free radicals and lipid hydroperoxides may have an aetiological role in the development of lesions in the central nervous system in patients with Alzheimer's disease and in those with vascular dementia. This study aimed to make a cross-sectional comparison of blood markers of oxidative stress in two groups of patients with these disorders and a control group.


METHODS
Cross-sectional comparative study.


METHODS
Established memory clinics in Cardiff organized by a University Department of Geriatric Medicine within an acute care NHS Trust.


METHODS
Following a dietary assessment, postprandial venous blood samples were obtained from the following: 25 subjects with probable Alzheimer's disease (AD) (mean age 74.3; 10 F, 15 M); 17 subjects with probable vascular dementia (VD) (mean age 75.5; 5 F, 12 M); and 41 controls (mean age 73.4; 24 F, 17 M) for measurement of circulating lipid peroxides (LP), total antioxidant capacity (TAC), vitamin C (VitC), vitamin E (VitE) and beta-carotene (BC).


RESULTS
Plasma levels of VitC were significantly lower in subjects with vascular dementia compared with controls (VD, 6.5 (4.8, 8.2); controls, 10.0 (8.38, 11.6); VD vs controls, p = 0.015), but no significant difference was seen between controls and patients with Alzheimer's disease (AD, mean 8.3 (6.2, 10.4)). VitE levels were significantly lower in subjects with AD compared with controls (31.1 (28.2, 34.0) vs 36.0 (32.8, 39.2), p = 0.035). BC levels were similar in subjects with AD and controls, but significantly elevated in those with VD (AD, 0.28 (0.2, 0.34); VD, 0.40, (0.27, 0.53); controls, 0.28 (0.22, 0.34); VD vs controls, p = 0.046). There were no significant differences in LP or TAC between the three groups.


CONCLUSIONS
Subjects with dementia attributed to Alzheimer's disease or to vascular disease have a degree of disturbance in antioxidant balance which may predispose to increased oxidative stress. This may be a potential therapeutic area for antioxidant supplementation.
Sinclair
A J
AJ
Academic Department of Geriatric Medicine and Gerontology, Selly Oak Hospital, Birmingham, UK.
Bayer
A J
AJ
Johnston
J
J
Warner
C
C
Maxwell
S R
SR
D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D000975:Antioxidants / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D003430:Cross-Sectional Studies; D015140:Dementia, Vascular / Q000503:physiopathology*; D005260:Female; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D008297:Male; D018384:Oxidative Stress
D000975:Antioxidants; D015415:Biomarkers; D005609:Free Radicals