Vitamin E in the primary prevention of rheumatoid arthritis: the Women's Health Study

Abstract

Objective: Vitamin E supplements may reduce the risk of developing rheumatoid arthritis (RA) through antioxidant effects. Although previous observational studies have investigated this question, no randomized trial data are available.

Methods: The Women's Health Study is a randomized, double-blind, placebo-controlled trial designed to evaluate the benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer among 39,876 female health professionals age > or = 45 years throughout the US, conducted between 1992 and 2004. After excluding women with self-reported RA at baseline, 39,144 women were included in the present study. The primary end point, definite RA, was confirmed using a connective tissue disease screening questionnaire, followed by medical record review for American College of Rheumatology criteria.

Results: During an average followup of 10 years, 106 cases of definite RA occurred, 50 in the vitamin E group and 56 in the placebo group. Sixty-four (60%) RA cases were rheumatoid factor positive and 42 (40%) were rheumatoid factor negative. There was no significant association between vitamin E and risk of definite RA (relative risk [RR] 0.89, 95% confidence interval [95% CI] 0.61-1.31). There were also no significant risk reductions for either seropositive RA (RR 0.64, 95% CI 0.39-1.06) or seronegative RA (RR 1.47, 95% CI 0.79-2.72).

Conclusion: Six hundred IU of vitamin E supplements taken every other day is not associated with a significant reduction in the risk of developing RA among women in a randomized, double-blind, placebo-controlled trial.

Trial registration: ClinicalTrials.gov NCT00000479.

Figures

Figure 1

Cumulative Incidence Rates of Definite Rheumatoid Arthritis and Seropositive Rheumatoid Arthritis by Randomized Vitamin E Assignment