High-Dose Vitamin E Does Not Increase Mortality in Alzheimer's Disease

Caroline Cassels

April 24, 2008

April 24, 2008 (Chicago, Illinois) — High-dose vitamin E does not increase mortality in Alzheimer's disease (AD) patients and, in fact, has been associated with improved survival in this population.

New research presented at the American Academy of Neurology (AAN) 60th Annual Meeting found that AD treatment regimens that included vitamin E at a dose of 2000 IU/day were associated with a 26% lower mortality rate than those that did not include the supplement.

"We think this study is reassuring in that rather than causing harm, treatment with vitamin E appears to be protective when you measure outcomes in terms of overall survival. It also suggests additional research on the use of vitamin E and treatment of Alzheimer's disease is warranted," study investigator Valory Pavlik, PhD, from Baylor College of Medicine, in Houston, Texas, told reporters attending an AAN press conference.

Based on research suggesting vitamin E may have a protective effect against AD in the general population and another study published in 2000 indicating high-dose supplementation may slow AD progression, Dr. Pavlik said clinicians at Baylor's Alzheimer's Disease and Memory Disorders Center have been using the supplement as an adjunct to antidementia treatment.

Recent meta-analyses have suggested that the supplement may have a harmful impact on outcomes, including mortality, in cardiovascular patients, which raised concerns this practice may also be detrimental in the AD population and were the impetus for this study.

Generalizable Findings?

"The extent to which these results were generalizable to dementia patients is not clear, but nevertheless they raised some controversy about the use of vitamin E," said Dr. Pavlik.

To determine whether AD patients taking high-dose vitamin E had reduced survival, investigators analyzed survival history of 847 probable AD patients attending the center from 1990 to 2004.

Deaths in the cohort were ascertained by telephone follow-up and were all confirmed by linkage to the National Death Index. Investigators then determined the relative risk of dying in individuals taking vitamin E alone or with another antidementia drug.

Less than 10% of the group took vitamin E alone, and approximately 15% of the study cohort did not take the vitamin. The average follow-up period was 4.9 years, with a range of 1 to 15 years.

After adjusting for demographic variables and disease severity at baseline, the investigators found that individuals taking regimens that included high-dose vitamin E had a 26% reduced mortality risk compared with individuals not taking the supplement.

Impact on Quality of Life?

To determine whether this main result was driven by vitamin E or antidementia medications, the investigators conducted 2 further comparisons. They looked at individuals who were taking vitamin E, with or without additional antidementia medication, and compared them with individuals taking no medication at all.

Among those taking vitamin E with or without another drug, the mortality rate was 23% lower over time, compared with those taking no drug, said Dr. Pavilk.

In addition, investigators compared patients taking cholinesterase inhibitors alone with those taking no drug and found individuals taking the antidementia treatment had a slightly higher-than-average mortality rate. However, Dr. Pavlik, emphasized this finding was not statistically significant.

In a follow-up interview with Medscape Neurology & Neurosurgery, study coauthor Rachelle Doody, MD, also from Baylor College of Medicine, said it is important to note that in addition to a possible extension of life, other research by Baylor investigators has shown that vitamin E may have an impact on AD patients' quality of life.

"Our research suggests AD patients who persist with their antidementia therapy from the beginning of the disease to the end and who also take high-dose vitamin E are more likely to live longer at a higher level of ability," she said.

Dr. Pavlik has no disclosures.

American Academy of Neurology 60th Annual Meeting: Abstract P03.076. Presented April 15, 2008.


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