Vitamin E Supplementation, Cardiovascular Events, and Cancer

Abstract

To the Editor: I am concerned about a potential confounder in the randomized controlled trial by the initial Heart Outcomes Prevention Evaluation (HOPE) and HOPE−The Ongoing Outcomes (HOPE-TOO) trial investigators on longterm vitamin E supplementation and cardiovascular events and cancer. There was no presentation of the prevalence of glitazone use in both treatment groups, whether this variable was controlled for in the data analysis, or whether the patients who developed new-onset heart failure had been taking glitazone drugs. Similarly, a breakdown of the percentage of patients from the United States, Canada, and Brazil, in which these drugs were marketed differently, would have been helpful.