AAN: High-Dose Vitamin E May Help Alzheimer Patients
By John Gever
CHICAGO, 16 april 2008-- High-dose vitamin E supplements do not worsen outcomes in patients with Alzheimer disease and may help, researchers said here. Patients taking 1,000 to 2,000 IU a day of vitamin E were 26% less likely to die than those not taking the vitamin, reported Valory Pavlik, Ph.D., of Baylor College of Medicine, at the American Academy of Neurology meeting. "There was no evidence that treatment with high doses of vitamin E had an adverse effect on survival," she said. The observational study of more than 800 patients was undertaken in the wake of several published meta-analyses of smaller trials in which high-dose vitamin E showed hints of higher mortality.
The Baylor study covered 847 patients followed for up to 15 years (mean 5.5 years, SD 2.8). These were patients at Baylor's Alzheimer's disease clinic from 1990 to 2004.
A senior co-author of the study, Rachelle Doody, M.D., Ph.D., also of Baylor, said it was not the case that patients taking vitamin E merely lived longer with severe impairment. She said a separate study in the same sample had shown their outcomes were better by a range of measures in addition to mortality.
Patients at the clinic were encouraged to take vitamin E supplements as an anti-dementia treatment, but were not required to do so.
At their last clinic visit before death or data analysis, 9% were taking vitamin E alone, 62% were taking an anticholinesterase drug and vitamin E, 13% were taking only an anticholinesterase drug, and 16% were not taking any drug.
The percentages varied at earlier clinic visits, but not markedly.
For all women taking vitamin E supplements, the hazard ratio for death was 0.74 relative to women taking either no drug or cholinesterase inhibitors alone (95% CI 0.58 to 0.93, P=0.009).
When non-significant covariates were excluded, the hazard ratio fell to 0.71 (95% CI 0.57 to 0.89, P=0.003).
A slight statistically insignificant increase in mortality risk was seen in patients taking anticholinesterase drugs without vitamin E (HR 1.20, P=0.27).
Comparing all patients taking vitamin E supplements, with or without cholinesterase inhibitors, with those taking no drug yielded a hazard ratio of 0.77 (95% CI 0.60 to 1.00, P=0.051).
Dr. Pavlik noted that the doses of vitamin E taken in the study were vastly higher than the recommended dietary allowance of 20 IU per day.
Doses higher than about 300 IU per day have been controversial since 2004, when meta-analyses were published that showed higher death rates among patients taking daily doses of 2,000 IU.
Dr. Pavlik said most patients in the studies included in those meta-analyses had heart disease.
She said the Baylor clinic began giving information sheets describing the potential risks of high-dose supplements to its patients. "Most patients continued to take vitamin E, but some dropped to 1,000 IU per day," she said.
She noted that the survival benefits found in the Baylor study were observed only after years of exposure.
Dr. Pavlik's presentation included a 15-year Kaplan-Meier chart indicating that it took about eight years for the survival curve for vitamin E-taking patients to diverge noticeably from the curves representing patients taking cholinesterase inhibitors alone and no drug.
Ranjan Duara, M.D., an Alzheimer specialist at the University of Miami who was not involved in the research, said the data were provocative but not persuasive at this point, since it wasn't a randomized trial.
"I'm not sure about the biases that may be present that affect mortality," he commented. "Individuals who took vitamin E religiously at that dose could have received better care overall," he said.
Dr. Duara said a similar phenomenon occurred in observational studies of estrogen treatment for Alzheimer's disease.
"People [who took estrogen] were much more vigilant about their healthcare," he said.
Still, he added, "if the data [in the Baylor study] are true and they can replicate those findings in a randomized trial, we'd have to take another look at vitamin E."
The study received funding from the National Institutes of Health, National Alzheimer's Association, and the Mitchell Foundation.
Dr. Doody reported relationships with Astellas, Bristol-Meyers Squibb, Comentis, Debiopharm, Eisai Inc., Epix, Forest Laboratories, Medivation, Novartis, Pfizer, sanofi-aventis Pharmaceuticals, Schering-Plough, Elan/Wyeth, GlaxoSmithKline, and Myriad Pharmaceuticals. No other potential conflicts of interest were reported.
Primary source: NeurologySource reference:Pavlik V, et al "Vitamin E use is associated with improved survival in an AD cohort" Neurology 2008; 70: A146-A147.
By John Gever
CHICAGO, 16 april 2008-- High-dose vitamin E supplements do not worsen outcomes in patients with Alzheimer disease and may help, researchers said here. Patients taking 1,000 to 2,000 IU a day of vitamin E were 26% less likely to die than those not taking the vitamin, reported Valory Pavlik, Ph.D., of Baylor College of Medicine, at the American Academy of Neurology meeting. "There was no evidence that treatment with high doses of vitamin E had an adverse effect on survival," she said. The observational study of more than 800 patients was undertaken in the wake of several published meta-analyses of smaller trials in which high-dose vitamin E showed hints of higher mortality.
The Baylor study covered 847 patients followed for up to 15 years (mean 5.5 years, SD 2.8). These were patients at Baylor's Alzheimer's disease clinic from 1990 to 2004.
A senior co-author of the study, Rachelle Doody, M.D., Ph.D., also of Baylor, said it was not the case that patients taking vitamin E merely lived longer with severe impairment. She said a separate study in the same sample had shown their outcomes were better by a range of measures in addition to mortality.
Patients at the clinic were encouraged to take vitamin E supplements as an anti-dementia treatment, but were not required to do so.
At their last clinic visit before death or data analysis, 9% were taking vitamin E alone, 62% were taking an anticholinesterase drug and vitamin E, 13% were taking only an anticholinesterase drug, and 16% were not taking any drug.
The percentages varied at earlier clinic visits, but not markedly.
For all women taking vitamin E supplements, the hazard ratio for death was 0.74 relative to women taking either no drug or cholinesterase inhibitors alone (95% CI 0.58 to 0.93, P=0.009).
When non-significant covariates were excluded, the hazard ratio fell to 0.71 (95% CI 0.57 to 0.89, P=0.003).
A slight statistically insignificant increase in mortality risk was seen in patients taking anticholinesterase drugs without vitamin E (HR 1.20, P=0.27).
Comparing all patients taking vitamin E supplements, with or without cholinesterase inhibitors, with those taking no drug yielded a hazard ratio of 0.77 (95% CI 0.60 to 1.00, P=0.051).
Dr. Pavlik noted that the doses of vitamin E taken in the study were vastly higher than the recommended dietary allowance of 20 IU per day.
Doses higher than about 300 IU per day have been controversial since 2004, when meta-analyses were published that showed higher death rates among patients taking daily doses of 2,000 IU.
Dr. Pavlik said most patients in the studies included in those meta-analyses had heart disease.
She said the Baylor clinic began giving information sheets describing the potential risks of high-dose supplements to its patients. "Most patients continued to take vitamin E, but some dropped to 1,000 IU per day," she said.
She noted that the survival benefits found in the Baylor study were observed only after years of exposure.
Dr. Pavlik's presentation included a 15-year Kaplan-Meier chart indicating that it took about eight years for the survival curve for vitamin E-taking patients to diverge noticeably from the curves representing patients taking cholinesterase inhibitors alone and no drug.
Ranjan Duara, M.D., an Alzheimer specialist at the University of Miami who was not involved in the research, said the data were provocative but not persuasive at this point, since it wasn't a randomized trial.
"I'm not sure about the biases that may be present that affect mortality," he commented. "Individuals who took vitamin E religiously at that dose could have received better care overall," he said.
Dr. Duara said a similar phenomenon occurred in observational studies of estrogen treatment for Alzheimer's disease.
"People [who took estrogen] were much more vigilant about their healthcare," he said.
Still, he added, "if the data [in the Baylor study] are true and they can replicate those findings in a randomized trial, we'd have to take another look at vitamin E."
The study received funding from the National Institutes of Health, National Alzheimer's Association, and the Mitchell Foundation.
Dr. Doody reported relationships with Astellas, Bristol-Meyers Squibb, Comentis, Debiopharm, Eisai Inc., Epix, Forest Laboratories, Medivation, Novartis, Pfizer, sanofi-aventis Pharmaceuticals, Schering-Plough, Elan/Wyeth, GlaxoSmithKline, and Myriad Pharmaceuticals. No other potential conflicts of interest were reported.
Primary source: NeurologySource reference:Pavlik V, et al "Vitamin E use is associated with improved survival in an AD cohort" Neurology 2008; 70: A146-A147.
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