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| News covering selected sessions related to migraine from 2008 medical conferences. |
| Annual Meeting of the American Academy of Neurology |
Chicago, IL April 15-18, 2008 |
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Longer Survival in Alzheimer’s Patients
Who Took Vitamin E |
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BY MARY JO M. DALES
Editorial Director |
CHICAGO
(ECCC)— Vitamin E supplementation at doses of 2,000
IU/day appeared to be associated with improved survival in a
retrospective case analysis of patients who had Alzheimer’s
disease.
The results, presented at the annual meeting of the American
Academy of Neurology, were seen in a retrospective case analysis
of 847 patients seen between 1990 and 2004 at the Alzheimer’s
Disease and Memory Disorders Center at Baylor College of
Medicine, Houston. The results do not indicate that high-dose
vitamin E was associated with an increased risk of
death in Alzheimer’s patients, as has been seen in large studies
of vitamin E for prevention of cardiovascular events.
All of the patients studied had probable or mixed Alzheimer’s
disease. About two-thirds of the subjects took 2,000 IU of
vitamin E, with or without a cholinesterase inhibitor; less than
10% took vitamin E alone; and approximately 15% did not take any
antidementia drug.
For those taking vitamin E, with or without a cholinesterase
inhibitor, there was a 26% reduction in risk of dying
(statistically significant at P = .009) at any time interval of
the analysis, compared with those not taking vitamin E.
The prescribing of high-dose vitamin E in Alzheimer’s disease
gained popularity after a 1997 study indicated that vitamin E at
doses of 2,000 IU/day appeared to slow the disease’s
progression. That approach fell into disfavor, however, when a
meta-analysis of 19 randomized controlled trials involving more
than 135,000 participants found that vitamin E supplementation
for at least 1 year at doses greater than 400 IU/day was
associated with increased all-cause mortality (Ann. Intern. Med.
2005;142:37-46).
Valory Pavlik, Ph.D., one of the investigators in the Baylor
study, said that many of the studies in the meta-analysis
examined vitamin E for prevention of cardiovascular events.
Vitamin E was not being used for treatment as it was in the
Baylor patients with Alzheimer’s disease.
To determine whether the risk of death was greater for
Alzheimer’s patients, Dr. Pavlik and her associates undertook
their analysis based on patients who were taking vitamin E
during the time before high-dose vitamin E fell into disfavor.
In the Baylor study, patients averaged 74 years old and ranged
in age from 65 to 83 years at their first visit to the Baylor
center. Two-thirds of the patients were women; they were
followed up for a median time of 5 years, with a range of 1-15
years.
Neuropsychological scores, clinical assessments, and medication
history were collected using standardized protocols. Vital
status was ascertained through contact with family members or
death index searches. Time-dependent Cox proportional hazards
modeling was used to calculate all-cause mortality hazard ratios
for vitamin E alone, or in combination with a cholinesterase
inhibitor, adjusting for demographics, duration of symptoms at
diagnosis, and baseline disease severity.
The adjusted hazard ratio associated with vitamin E (with or
without a cholinesterase inhibitor) was 0.74 (95% CI =
0.59-0.92, P = .008), and for cholinesterase inhibitor use (with
or with
out vitamin E), was 0.91 (95% CI = 0.72-1.14, P = .393). The
hazard ratios corresponding to mutually exclusive treatment
categories (reference group = no drug treatment) were 0.79 (P =
0.069) for vitamin E with another drug, 1.1 (P = .515) for
cholinesterase inhibitor use only, and 0.82 (P = .341) for
vitamin E only.
Dr. Pavlik emphasized that this was an observational study and
not a randomized controlled trial. Alternatively, this group of
patients was followed for longer times than were many of the
patients in clinical trials. Further, survival rates were
comparable or better among patients on
cholinesterase inhibitors who also took vitamin E supplements at
doses of 2,000 IU/day than they were among patients on
cholinesterase inhibitors alone.
During a press conference, Dr. Pavlik said the lowest effective
dose for vitamin E in Alzheimer’s disease has not been
determined. A dose-response study conducted at Vanderbilt
University, Nashville, Tenn., has indicated that the antioxidant
action of vitamin E begins to occur at doses exceeding 1,000
IU/day. |
| Copyright 2008 Elsevier Custom Conference Coverage. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, through negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Because of rapid advances in the medical sciences, the Publisher recommends that independent verification of diagnoses and drug dosages should be made. Opinions expressed in this publication are those of the original authors and do not necessarily reflect those of the Publisher, the sponsor, or the editors. Elsevier assumes no liability for any material published herein. |
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