Effect of Selenium on Triglyceride and Total Cholesterol, Weight Gain, and Physical Activity on Hemodialysis Patients: A Randomized Double-Blinded Controlled Trial

Selenium supplementation in chronic kidney disease patients undergoing haemodialysis: a systematic review of the effects on plasma selenium, antioxidant and inflammatory markers, immunological parameters and thyroid hormones

Selenium (Se) is a mineral with several biological functions, and studies have shown that its deficiency can be linked to many complications in patients with chronic kidney disease (CKD). This study aims to systematically review the effects of Se supplementation in patients with CKD undergoing haemodialysis (HD). This systematic review was carried out according to the PRISMA statement. Clinical trials were searched in PubMed, Lilacs, Embase, Scopus and Cochrane Library databases from inception to July 2021 and updated in July 2024. The protocol was registered on PROSPERO (CRD42021231444). Two independent reviewers performed the study screening and data extraction, and the risk of bias was evaluated using the Cochrane Collaboration tool. Thirteen studies were included in this review. Only nine studies showed results on Se levels; in all, reduced Se levels were observed before supplementation. A positive effect of supplementation on plasma Se level was demonstrated. Of the ten studies analysed, six demonstrated positive effects on antioxidant and inflammatory markers. Only one study analysed immunological parameters, showing a positive impact. From two studies that analysed thyroid hormones, only one showed positive results. All studies were classified as high risk of bias. The findings suggest that Se supplementation significantly increases plasma Se levels in these patients; however, there are still not enough studies to clarify the effects of Se supplementation on the antioxidant and inflammatory markers, immune system and thyroid hormones. Further studies are needed to elucidate the effects of Se supplementation and to provide a recommendation for patients with CKD undergoing HD.

Effects of Selenium Administration on Blood Lipids: A Systematic Review and Dose-Response Meta-Analysis of Experimental Human Studies

CONTEXT

Overexposure to the essential trace element selenium has been associated with adverse metabolic and cardiovascular outcomes, hypertension, and diabetes. However, dose-response meta-analyses analyzing the effects of selenium administration on the lipid profile in experimental human studies are lacking.

OBJECTIVE

Through a restricted cubic spline regression meta-analysis, the dose-response relation between the dose of selenium administered or blood selenium concentrations at the end of the trials and changes over time in blood lipids, ie, total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, and triglycerides was assessed.

DATA SOURCES

Searches were performed on PubMed, Web of Science, Embase, and the Cochrane Library from inception up to January 11, 2025 to identify randomized controlled trials (RCTs) investigating the impact of selenium supplementation on blood lipid profiles among adults.

DATA EXTRACTION

A total of 27 eligible RCTs that enrolled healthy individuals, pregnant individuals, and participants with specific health conditions were identified and the relevant data was extracted.

DATA ANALYSIS

Dose-response analysis indicated that selenium administration at and above 200 µg/day decreased HDL and LDL cholesterol and increased triglyceride levels. Blood selenium concentrations at the end of the trial above approximately 150 µg/L were positively associated with triglyceride and LDL cholesterol concentrations, and inversely associated with HDL cholesterol. Inorganic selenium supplementation showed stronger associations than organic selenium. At the lowest levels of baseline intake, selenium supplementation appeared instead to have beneficial effects on the lipid profile, with an overall indication of U-shaped curves, apart from HDL-cholesterol. The adverse effects of selenium were stronger in studies involving healthy participants as compared with unhealthy participants and pregnant females, in those having a longer duration of the intervention, particularly more than 3 months, and in European populations at selenium intake levels of above 300 µg/day.

CONCLUSIONS

In this dose-response meta-analysis of experimental human studies, an adverse effect of selenium administration on blood lipids at levels around or above the current upper level of intake was observed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration No. CRD42022380432.

Effect of selenium supplementation on hemodialysis patients: a meta-analysis

PURPOSE

Hemodialysis (HD) patients commonly experience enhanced oxidative stress and inflammation, potentially increasing the risk of malnutrition. Selenium levels are typically lower in HD individuals. Selenium deficiency has been identified as a risk factor for oxidative stress and inflammatory responses. Therefore, we intended to perform a meta-analysis to assess the impact of selenium supplementation on HD patients.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched for randomized controlled trials (RCTs) on the effect of selenium supplementation on HD patients until September 31, 2024. The data analysis was conducted using Stata15.0 software.

RESULTS

Seven RCTs, with 2080 participants, were finally included, with 1029 in the selenium group and 1051 in the control group. The meta-analysis unraveled no statistically significant impact of selenium supplementation on body mass index (SMD = 0.15, 95% CI (- 0.20, 0.49), triglyceride [(SMD = - 0.02, 95% CI (- 0.44, 0.41)], total cholesterol [(SMD = - 0.18, 95%CI (- 0.41, 0.05)], low-density lipoprotein [(SMD = - 0.37, 95% CI (- 1.04, 0.31)], high-density lipoprotein cholesterol [(SMD = 0.15, 95% CI (- 0.54, 0.84)], C-reactive protein [(SMD = - 0.10, 95% CI (- 0.46, 0.27)], ferritin [(SMD = - 0.02, 95% CI (- 0.29, 0.26)], Hx-C reactive protein [(SMD = 0.00, 95% CI (- 1.02, 1.03)], and hemoglobin [(SMD = 0.01, 95% CI (- 0.57,0.59)]. Only selenium levels were significantly increased after selenium supplementation [SMD = 2.83, 95% CI (2.43, 3.24)].

CONCLUSION

Selenium supplementation can increase selenium levels in HD patients, without notable impacts on weight, triglycerides, and total cholesterol.

The effects of selenium supplementation on lipid profile in adults: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Dyslipidemia with a considerable progression rate is a primary risk factor for CVDs if left untreated. Dietary interventions have explored the health influences of selenium on lipid profiles in adults, yet the findings remain contentious. This study seeks to determine if selenium supplementation can positively modify the lipid profile (total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein cholesterol (VLDL), and high-density lipoprotein cholesterol (HDL-C) in adults.

METHODS

Using predefined keywords, we searched online databases, including Scopus, PubMed, Web of Science Core Collection, and Google Scholar, for relevant studies published from inception through July 2024. A random-effects meta-analysis was then employed to pool the weighted mean differences (WMD) and 95 % CI for outcomes assessed by a minimum of three studies.

RESULTS

Initially 1205 studies were obtained out of which 25 RCTs were decided to be included for further analyses. Selenium supplementation reduced VLDL (WMD: -1.53; 95 % CI: -2.86, -0.20), but did not change TG (WMD: 1.12; 95 % CI: -4.51, 6.74), TC (WMD: -2.25; 95 % CI: -6.80, 2.29), LDL-C (WMD: 1.60; 95 % CI: -4.26, 7.46), and HDL-C levels (WMD: 0.98; 95 % CI: - 0.02, 1.98).

CONCLUSION

Our study showed significantly reduced VLDL but limited effects were observed in other lipid indexes. More extensive RCTs are required globally to achieve a holistic comprehension of the connection between selenium and lipid profile.

The effect of selenium supplementation on oxidative stress, clinical and physiological symptoms in patients with migraine: a double-blinded randomized clinical trial

Background and Aim

The present double-blinded randomized clinical trial aimed to investigate the effect of selenium supplementation on oxidative stress, clinical, and physiological symptoms in patients with migraine.

Methods

In total, 72 patients with migraine were randomly assigned to receive either 200 μg/day selenium (n = 36) or placebo (n = 36) for 12 weeks. Clinical traits of migraine (e.g., severity, frequency, and duration of headaches), mental health indices (e.g., depression, anxiety, and distress), quality of life, biomarkers of oxidative stress (e.g., nitric oxide [NO], malondialdehyde [MDA], total antioxidant capacity [TAC], total oxidant status [TOS]), and anthropometric indices were assessed at baseline and at the end of the study.

Results

Selenium supplementation resulted in a significant reduction in NO (-1.24 ± 0.43 vs. 0.16 ± 0.43; p = 0.03) levels and a significant increase in TAC (9.89 ± 2.50 vs. -0.18 ± 2.50; p = 0.01) compared to the placebo group. Moreover, selenium supplementation had a significant protective effect against MDA levels compared to placebo (0.33 ± 0.57 vs. 1.83 ± 0.57; p = 0.03). In addition, selenium intake was associated with a lower headache frequency (-8.15 ± 0.77 vs. -4.12 ± 0.77; p < 0.001) and severity (-2.89 ± 0.42 vs. -1.16 ± 0.42; p = 0.01) as well as a lower Headache Impact Test-6 (HIT-6) score (-9.22 ± 2.00 vs. -2.08 ± 2.00; p = 0.02) compared to the controls. For other outcome variables, we found no significant effect.

Conclusion

Selenium supplement may be considered a complementary therapy in patients with migraine due to its beneficial effects on oxidative stress and migraine symptoms. Further studies are needed to affirm our findings.Clinical Trial Registration: This study was registered in the Iranian Registry of Clinical Trials (https://www.irct.ir) on 27 May 2023 with code number of IRCT20121216011763N60.

Effect of Selenium Supplementation on Lipid Profile, Anemia, and Inflammation Indices in Hemodialysis Patients

Objective

Trace elements deficiency is common among end-stage renal disease (ESRD) patients due to excessive loss during dialysis and the lower intake secondary to loss of appetite. Selenium (Se) is a trace element that plays an important role in the radical scavenging system and helps the body defend against oxidative stress. This study aims to evaluate the effects of Se supplementation on lipid profile, anemia, and inflammation indices in ESRD patients.

Methods

Fifty-nine hemodialysis patients enrolled and were randomly divided into two groups. Two hundred microgram Se capsules once daily for the case group and matching placebo for the control group were administered for three months. Demographic data were collected at the study beginning. Uric acid (UA), anemia and inflammation indices, and lipid profiles were recorded at the beginning and the end of the study.

Findings

UA and UA-to-HDL (high-density lipoprotein) ratio decreased significantly in the case group (P < 0.001). The changes in lipid profile were not significant among both groups. Hemoglobin slightly increased in the case group, however, it decreased significantly in the control group (P = 0.031). High-sensitivity C-reactive protein (hs-CRP) decreased in the case group and increased in the control group, however, none of these changes were significant.

Conclusion

According to the results of this study, selenium supplementation in ESRD patients could reduce some risk factors related to their mortality, such as the ratio of uric acid to HDL. However, the changes related to lipid profile, hemoglobin level and hs-CRP biomarker were not significant.

Erratum: Effect of Selenium on Triglyceride and Total Cholesterol, Weight Gain, and Physical Activity on Hemodialysis Patients: A Randomized Double-Blinded Controlled Trial

[This corrects the article on p. 63 in vol. 13, PMID: 35706870.].