Effect of vitamins and aspirin on markers of platelet activation, oxidative stress and homocysteine in people at high risk of dementia.

Abstract

OBJECTIVES:

To examine the association of cognitive impairment with platelet activation and reactive oxygen species and total homocysteine levels; and to assess the biochemical efficacy of treatment with aspirin and vitamin supplements in people at high risk of dementia.

SUBJECTS:

People with dementia or mild cognitive impairment.

DESIGN AND INTERVENTION:

In a 2 x 2 x 2 factorial design trial, 149 people at high-risk of dementia were randomized to receive either low-dose aspirin (81 mg) or placebo; and folic acid (2 mg) plus vitamin B12 (1 mg) or placebo; and vitamins E (500 mg) plus C (200 mg) or placebo. Participants were seen twice before and once after 12 weeks of treatment.

MAIN OUTCOME MEASURES:

At each visit, participants had their cognitive function assessed and had blood collected for homocysteine, folate and vitamin B12 determination and urine collected for markers of platelet activation (11-dehydro-thromboxane B2) and reactive oxygen species (8-epi-PGF2 alpha).

RESULTS:

Prior to treatment, cognitive function was inversely related with homocysteine and with urinary thromboxane and isoprostane, and these associations were independent of age. Aspirin was associated with a median reduction in 11-dehydrothromboxane B2 of 73% (P < 0.001). B-vitamins lowered plasma homocysteine concentration by 30% (P < 0.0001) and antioxidant vitamins lowered isoprostane excretion by 26% (P < 0.1). No effect of treatment on cognitive function was detected.

CONCLUSIONS:

Aspirin and B-vitamins were effective in reducing biochemical factors associated with cognitive impairment in people at risk of dementia. Large-scale trials are now required to assess the relevance of aspirin and B-vitamins for the maintenance of cognitive function in people at risk of dementia.

• Authors: Robert Clarke, Georgina Harrison, Sue Richards, Vital Trial Collaborative Group
• Journal: Journal of internal medicine (J Intern Med) Vol. 254 Issue 1 Pg. 67-75 (Jul 2003) ISSN: 0954-6820 [Print] England
• PMID: 12823643 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Isoprostanes
• Platelet Aggregation Inhibitors
• Thromboxanes
• Vitamins
• Homocysteine
• Folic Acid
• Vitamin B 12
• Aspirin
• Riboflavin

Topics

• Aged
• Aged, 80 and over
• Aspirin (therapeutic use)
• Cognition Disorders (prevention & control)
• Dementia (prevention & control)
• Female
• Folic Acid (blood)
• Follow-Up Studies
• Homocysteine (blood)
• Humans
• Isoprostanes (blood)
• Male
• Middle Aged
• Oxidative Stress
• Platelet Activation (drug effects)
• Platelet Aggregation Inhibitors (therapeutic use)
• Riboflavin (therapeutic use)
• Thromboxanes (blood)
• Vitamin B 12 (therapeutic use)
• Vitamins (therapeutic use)