Effect of Selenium Supplementation on Lipid Profile: A Systematic Review and Meta-Analysis

Abstract

Selenium is an essential mineral that plays a key role in plenty of major metabolic processes. A growing body of literature has shown that selenium deficiency leads to an increase in plasma TC and TG levels. This study explores the effect of selenium supplementation on serum level of lipid profile [total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), very low density lipoprotein (VLDL)]. We systematically searched PubMed/MEDLINE, ISI/WOS, and Scopus (from their commencements to Jan 2016) to identify the papers investigating the association between the intake of selenium and lipid profile. Data extracted from the relevant studies were screened. The pooled standardized mean difference was estimated using the random or fixed effects model. Heterogeneity among the studies was assessed using Q-test. Of the potentially relevant articles screened, 11 articles including 1221 participants were included in this meta-analysis. Results of meta-analysis showed that intake of selenium resulted in a statistically significant improvement in TC, [(SMD): –0.13, 95% CI: (–0.24, –0.02)], TG [(SMD): –0.19, 95% CI: (–0.38, –0.01)] and VLDL [(SMD): –0.34, 95% CI: (–0.63, –0.05)]. The selenium supplementation did not significantly improve lipid profile such as LDL [(SMD): –0.08, 95% CI: (–0.036, 0.19)], HDL [(SMD): 0.01, 95% CI: (–0.164, 0.18)], HDL/TC ratio [(SMD): 0.025, 95% CI: (–0.11, 0.16)], non-HDL-C [(SMD): 0.018, 95% CI: (–0.13, 0.16)]. This meta-analysis suggests that the effect of selenium supplementation on the serum levels of TG and VLDL is marginally significant. However, the supplementation has no effect on other serum lipids. Moreover, the study shows that the effect of selenium supplementation on lipid profile is negative.

A Nutrigenetic Update on CETP Gene–Diet Interactions on Lipid-Related Outcomes

“…In another cross-sectional study of 1315 Spanish participants [ 86 ], higher plasma selenium levels were found to be associated with elevated LDL levels in all the three genotypes of the SNP rs1800774 but participants with two copies of the major allele (‘C’) had lower LDL compared to those with ‘CT’ and ‘TT’ genotypes (odds ratio per an interquartile range increase in plasma selenium (95% confidence interval): 0.97 (0.74 to 1.27) for ‘CC’, 1.76 (1.38 to 2.25) for ‘CT’, 3.20 (1.93 to 5.28) for ‘TT’ genotype; P interaction = 0.0002). Selenium was also reported to be associated with lipid levels in a systematic review and meta-analysis [ 87 ], but it was shown to be linked to significant improvement in the levels of TC and TG and had no significant effect on LDL levels. A systematic review published in 2017, in which the results of 23 gene–diet interaction studies involving CETP were analysed [ 88 ], concluded that SNPs in the CETP gene may influence the effect of dietary factors on metabolic traits but that the findings from these studies were inconsistent and suggest that multiple factors might be involved.…”

Dietary Intakes Are Associated with HDL-Cholesterol in Survivors of Childhood Acute Lymphoblastic Leukaemia

“…Here, we found a positive relationship between selenium intake and HDL-C. To our knowledge, this has not been investigated elsewhere. However, the impact of selenium blood levels or supplementation on HDL-C is conflicting: a study reported a positive association [77] whereas others did not find any relationship [78][79][80].…”

High selenium levels associate with reduced risk of mortality and new‐onset heart failure: data from PREVEND

“…Patients who received selenium supplementation in a replete population had higher incidence of diabetes mellitus 28 ; however, no differences have been reported in randomized controlled trials in populations with low selenium levels 29 . Similarly, the effects of selenium on cholesterol levels are inconclusive, although a recent meta‐analysis of 11 studies has shown marginal, but significant improvement of total cholesterol levels 30 . Since our findings contrast with the results of interventional studies, it is likely that higher dietary intake may explain the increased glucose and cholesterol levels with higher selenium status in our cohort.…”