Circulating vitamin E and cardiometabolic measures: a Mendelian randomization analysis

Abstract

Although a large body of literature reported that high intake of vitamin E played a possible role in reducing risk of cardiometabolic diseases, conflicting results were also found in some observational studies due to confounding factors. Hence, we used a Mendelian randomization study as an alternative way to examine the causality between circulating vitamin E and cardiometabolic diseases. Summary level data were extracted from consortia and three single nucleotide polymorphisms were used as instrumental variables. Our study showed that a one SD increase in circulating vitamin E levels was causally associated with an increased risk of coronary artery disease [odds ratio (OR) 3.16 (95%CI 1.74, 5.73); p = 1.91 × 10-3 ] at the Bonferroni adjusted level of significance (p<0.005). Moreover, a one SD increase in circulating vitamin E levels was associated with a 0.572 SD increase in low density lipo protein cholesterol (mg/dl), a 0.693 SD increase in total cholesterol (mg/dl), and a 1.45 SD increase in triglyceride (mg/dl), but a 0.502 SD decrease in high density lipoprotein cholesterol (mg/dl) at the Bonferroni adjusted level of significance (p<0.0028). Our findings indicated that genetically elevated vitamin E was associated with increased risk of coronary artery disease, suggesting an adverse causality between circulating vitamin E and coronary artery disease.

Diet-Derived Circulating Antioxidants and Risk of Coronary Heart Disease

“…Two previous studies using an MR approach found that a genetic predisposition to high vitamin E level was associated with increased risk of CAD (45,46).…”

Vegetable intake and metabolic risk factors: A Mendelian randomization study

“…Furthermore, recent meta-analyses of randomized trials found that vitamin C supplementation was not associated with TC, TG, LDL, HDL [40–42], glucose, HbA1c and insulin [40,43], in line with the findings from multiple MR studies that circulating vitamin C level did not change lipids, BMI, BP [44] and glycemic traits [45]. For vitamin E, MR evidence showed that circulating vitamin E was not associated with BMI, or glucose traits [46]. Our findings of the null effects of vegetable intake are actually consistent with these recent trial and MR evidences on the antioxidants.…”

A Mini-Overview of Vitamin E

“…Wang and Xu (2019) added that higher vitamin E may increase the risk of CAD/MI and safety and efficacy of vitamin E supplementation use should be reevaluated. Fan et al (2019) found that genetically elevated vita-min E was associated with increased risk of coronary artery disease, suggested an adverse causality between circulating vitamin E and coronary artery disease. 4-Stroke: The evidence did not suggest that vitamin E supplements protect against stroke.…”