Vitamin E and Risk of Type 2 Diabetes in the Women’s Health Study Randomized Controlled Trial
- Simin Liu123,
- I-Min Lee12,
- Yiqing Song1,
- Martin Van Denburgh1,
- Nancy R. Cook12,
- JoAnn E. Manson12 and
- Julie E. Buring1245
- 1Division of Preventive Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- 2Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts
- 3Department of Epidemiology and Center for Human Nutrition, University of California, Los Angeles, California
- 4Division of Aging, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- 5Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, Massachusetts
- Address correspondence and reprint requests to Simin Liu, MD, ScD, Department of Epidemiology, UCLA School of Public Health, 71-254 CHS, Box 951772, 650 Charles E. Young Dr. South, Los Angeles, CA 90095-1772. E-mail: siminliu{at}ucla.edu
Abstract
We directly assessed the efficacy of vitamin E supplements for primary prevention of type 2 diabetes among apparently healthy women in the Women’s Health Study randomized trial. Between 1992 and 2004, 38,716 apparently healthy U.S. women aged ≥45 years and free of diabetes, cancer, and cardiovascular disease were in two randomly assigned intervention groups and received 600 IU of vitamin E (α-tocopherol, n = 19,347) or placebo (n = 19,369) on alternate days. During a median 10-year follow-up, there were 827 cases of incident type 2 diabetes in the vitamin E group and 869 in the placebo group, a nonsignificant 5% risk reduction (relative risk [RR] 0.95 [95% CI 0.87–1.05], P = 0.31). There was no evidence that diabetes risk factors including age, BMI, postmenopausal hormone use, multivitamin use, physical activity, alcohol intake, and smoking status modified the effect of vitamin E on the risk of type 2 diabetes. In a sensitivity analysis taking compliance into account, women in the vitamin E group had an RR of 0.93 (95% CI 0.83–1.04) (P = 0.21) compared with those randomized to placebo. In this large trial with 10-year follow-up, alternate-day doses of 600 IU vitamin E provided no significant benefit for type 2 diabetes in initially healthy women.
Footnotes
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Clinical trial reg. no. NCT00000479, clinicaltrials.gov.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Accepted July 11, 2006.
- Received April 6, 2006.
- DIABETES
