Is vitamin E supplementation effective in reducing mortality related to cardiovascular events in people with type 2 diabetes mellitus? A systematic review

ObjectiveTo determine the effect of vitamin E in reducing cardiovascular mortality in diabetic patients.Data sourceReview of several English language primary studies published from 2004 to 2015.Outcome measuredThe primary outcomes measure by all studies included 30-day mortality due to congestive heart failure, myocardial infarction, stroke, and HDL function as it relates to cardiovascular outcomes. The secondary outcomes included hospitalization for CHF and coronary revascularization.ResultsFive Randomized, double-blind, placebo-controlled trials and 11 studies were used for this review. The study published by Jaxa-Chamiec et al. showed that vitamin E is beneficial along with vitamin C but is not effective when used alone. The study facilitated by Marchioli et al., showed that vitamin E supplementation is associated with a statistically non-significant (p = 0.18) increased risk of developing CHF. Finally, a study by Milman et al. showed that vitamin E supplementation is beneficial compared with a placebo group. This was a recurring theme and common finding among the studies explored within the context of this review.ConclusionsAlthough, two studies showed no benefit from vitamin E supplementation, the remaining studies demonstrated that vitamin E supplementation provided cardiovascular benefits in a specific diabetic subpopulation. The study population that derived a favorable outcome from vitamin E supplementation consisted of diabetic patients with the Hp 2–2 genotype. Hence, further studies should be conducted in diabetic populations with the Hp 2–2 genotype for identifying the definitive effects of vitamin E.