January 8, 2014
Vitamin E Slows Functional Decline in Alzheimer’s
Minneapolis—A daily dose of 2,000 IUs of vitamin E slowed functional decline in patients with mild-to-moderate Alzheimer’s disease (AD) without significantly increasing mortality rates in the treatment group, according to new research.
The study, appearing recently in the Journal of the American Medical Association, was led by researchers at the Minneapolis VA Health Care System and involved 613 patients at 14 VA medical centers.
Therapy with alpha tocopherol, a fat-soluble vitamin (E) and antioxidant, has been studied in patients with moderately severe AD and in participants with mild cognitive impairment (MCI) but had not been studied in patients with mild-to-moderate AD, according to background in the study.
In this study, researchers examined the effectiveness and safety of vitamin E and a drug, memantine—which has been shown to be effective in patients with AD and moderately severe dementia. Those products individually and in combination were tested in patients with mild-to-moderate AD who were taking an acetylcholinesterase inhibitor.
Participants were divided into four groups—152 received 2,000 IU/day of vitamin E; 155 received 20 mg/d of memantine; 154 received a combination, and 152 were given a placebo.
Functional decline was measured using the Alzheimer’s disease Cooperative Study/Activities of Daily Living (ADCS-ADL) Inventory score, which has a range of 0 to 78 and involves caregiver reporting.
Results indicated that, over the average follow-up time of 2.3 years, participants receiving vitamin E had slower functional decline than those receiving placebo, with the annual rate of decline in ADLs reduced by 19%. Study authors note that the reduction translates into a clinically meaningful delay in progression in the vitamin E group of 6.2 months. In addition, caregiver time was reduced by about 2 hours a day in that group.
No clinical benefit was detected for either memantine or the combination of vitamin E and memantine in the trial.
Differences in all-cause death and safety were only seen in the serious adverse event of “infections or infestations” with greater frequencies in the memantine group (31 events in 23 participants) and combination groups (44 events in 31 participants) compared with placebo (13 events in 11 participants).
“In contrast to the conclusion drawn from a 2005 meta-analysis of vitamin E, which showed that high-dose vitamin E (≥ 400 IU/d) may increase the risk of all-cause mortality, we found no significant increase in mortality with vitamin E,” the authors write. “The annual mortality rate was 7.3% in the alpha tocopherol group vs. 9.4% for the placebo group.”
Noting that decline in functioning in AD is increasingly recognized as an important determinant of both patient quality of life and social and economic costs, the authors point out, “In the current study, the placebo group lost approximately three units more on the ADCS-ADL Inventory than the alpha tocopherol group. A loss of this magnitude could translate into either the complete loss of being able to dress or bath independently, for example, or losing independence on any three different ADLs. Because vitamin E is inexpensive, it is likely these benefits are cost-effective as alpha tocopherol improves functional outcomes and decreases caregiver burden.”
|U.S. Pharmacist Social Connect