title: Effects of long-term vitamin E supplementation on cardiovascular events and cancer: a randomized controlled trial.
abstract: BACKGROUND
  Experimental and epidemiological data suggest that vitamin E supplementation may prevent cancer and cardiovascular events. Clinical trials have generally failed to confirm benefits, possibly due to their relatively short duration.
  
  
  OBJECTIVE
  To evaluate whether long-term supplementation with vitamin E decreases the risk of cancer, cancer death, and major cardiovascular events.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled international trial (the initial Heart Outcomes Prevention Evaluation [HOPE] trial conducted between December 21, 1993, and April 15, 1999) of patients at least 55 years old with vascular disease or diabetes mellitus was extended (HOPE-The Ongoing Outcomes [HOPE-TOO]) between April 16, 1999, and May 26, 2003. Of the initial 267 HOPE centers that had enrolled 9541 patients, 174 centers participated in the HOPE-TOO trial. Of 7030 patients enrolled at these centers, 916 were deceased at the beginning of the extension, 1382 refused participation, 3994 continued to take the study intervention, and 738 agreed to passive follow-up. Median duration of follow-up was 7.0 years.
  
  
  METHODS
  Daily dose of natural source vitamin E (400 IU) or matching placebo.
  
  
  METHODS
  Primary outcomes included cancer incidence, cancer deaths, and major cardiovascular events (myocardial infarction, stroke, and cardiovascular death). Secondary outcomes included heart failure, unstable angina, and revascularizations.
  
  
  RESULTS
  Among all HOPE patients, there were no significant differences in the primary analysis: for cancer incidence, there were 552 patients (11.6%) in the vitamin E group vs 586 (12.3%) in the placebo group (relative risk [RR], 0.94; 95% confidence interval [CI], 0.84-1.06; P = .30); for cancer deaths, 156 (3.3%) vs 178 (3.7%), respectively (RR, 0.88; 95% CI, 0.71-1.09; P = .24); and for major cardiovascular events, 1022 (21.5%) vs 985 (20.6%), respectively (RR, 1.04; 95% CI, 0.96-1.14; P = .34). Patients in the vitamin E group had a higher risk of heart failure (RR, 1.13; 95% CI, 1.01-1.26; P = .03) and hospitalization for heart failure (RR, 1.21; 95% CI, 1.00-1.47; P = .045). Similarly, among patients enrolled at the centers participating in the HOPE-TOO trial, there were no differences in cancer incidence, cancer deaths, and major cardiovascular events, but higher rates of heart failure and hospitalizations for heart failure.
  
  
  CONCLUSIONS
  In patients with vascular disease or diabetes mellitus, long-term vitamin E supplementation does not prevent cancer or major cardiovascular events and may increase the risk for heart failure.
authors.affiliation: Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario.
authors.forename: Eva
authors.initials: E
authors.lastname: Lonn
authors.forename: Jackie
authors.initials: J
authors.lastname: Bosch
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.forename: Patrick
authors.initials: P
authors.lastname: Sheridan
authors.forename: Janice
authors.initials: J
authors.lastname: Pogue
authors.forename: J Malcolm O
authors.initials: JM
authors.lastname: Arnold
authors.forename: Catherine
authors.initials: C
authors.lastname: Ross
authors.forename: Andrew
authors.initials: A
authors.lastname: Arnold
authors.forename: Peter
authors.initials: P
authors.lastname: Sleight
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Probstfield
authors.forename: Gilles R
authors.initials: GR
authors.lastname: Dagenais
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000517:prevention & control*; D003920:Diabetes Mellitus; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012306:Risk; D014652:Vascular Diseases; D024502:alpha-Tocopherol / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D024502:alpha-Tocopherol