Objective: To determine whether vitamin E would slow the progression of cognitive deterioration and dementia in aging persons with Down syndrome (DS).
Methods: A randomized, double-blind controlled clinical trial was conducted at 21 clinical sites, and researchers trained in research procedures recruited adults with DS older than 50 years to participate. Participants were randomly assigned to receive 1,000 IU of vitamin E orally twice daily for 3 years or identical placebo. The primary outcome was change on the Brief Praxis Test (BPT). Secondary outcomes included incident dementia and measures of clinical global change, cognition, function, and behavior.
Results: A total of 337 individuals were randomized, 168 to vitamin E and 169 to placebo. Both groups demonstrated deterioration on the BPT with no difference between drug and placebo. At baseline, 26% were diagnosed with dementia and there was an overall rate of incident dementia of 11%/year with no difference between groups. There was no effect on the secondary outcome measures. Though numerically higher in the treatment group, there was no difference in the number of adverse events (p = 0.079) and deaths (p = 0.086) between groups.
Conclusions: Vitamin E did not slow the progression of cognitive deterioration in older individuals with DS.
Classification of evidence: This study provides Class II evidence that vitamin E does not significantly slow the progression of cognitive deterioration in aging persons with DS.
© 2016 American Academy of Neurology.