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1.
Diverse Associations of Plasma Selenium Concentrations and SELENOP Gene Polymorphism with Metabolic Syndrome and Its Components.
Zhou, L, Luo, C, Yin, J, Zhu, Y, Li, P, Chen, S, Sun, T, Xie, M, Shan, Z, Cao, B, et al
Oxidative medicine and cellular longevity. 2020;:5343014
Abstract
The relationship between selenium and metabolic syndrome (MetS) has been discussed controversially, and limited studies have examined the associations of single nucleotide polymorphisms in selenoproteins genes with MetS. Hence, to examine the associations of plasma selenium concentrations and selenoprotein P rs7579 polymorphism with MetS, a case-control study of 1279 MetS cases and 1279 sex- and age- (±2 years) matched controls was conducted based on the baseline data of the Tongji-Ezhou Cohort study. Plasma selenium concentrations were measured by inductively coupled plasma mass spectrometry. MetS was defined using the definition of the Joint Interim Statement, adjusted for the Chinese population. In addition, the rs7579 polymorphism was genotyped by the Agena MassARRAY System. Plasma selenium concentrations in the MetS group were higher than in the control group (93.88 μg/L (83.17-107.41) vs. 92.66 μg/L (82.36-103.53), P < 0.05). Compared with quartile 4 (≥103.53 μg/L), the multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) associated with MetS were 0.79 (0.59-1.06) for quartile 1 (<82.36 μg/L), 0.75 (0.56-1.01) for quartile 2 (82.37-92.66 μg/L), and 0.61 (0.45-0.83) for quartile 3 (92.67-103.52 μg/L). The cubic spline analyses revealed a U-shaped association between plasma selenium and MetS, with the lowest risk at around 93.69 μg/L. Moreover, in cubic spline analyses, plasma selenium showed U-shaped associations with central obesity and high blood pressure, positive associations with hypertriglyceridemia and hyperglycemia, and a negative association with low high-density lipoprotein cholesterol. Additionally, both the GA and GA+AA genotype carriers were associated with increased ORs of MetS comparing with the GG genotype carriers. Our findings suggested a U-shaped association between plasma selenium and MetS and diverse associations between plasma selenium and components of MetS. Furthermore, our study found that the A allele of rs7579 was associated with higher odds of MetS. Further studies are needed to confirm our findings and elucidate the underlying mechanisms.
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2.
Selenium and Polycystic Ovary Syndrome; Current Knowledge and Future Directions: A Systematic Review.
Hajizadeh-Sharafabad, F, Moludi, J, Tutunchi, H, Taheri, E, Izadi, A, Maleki, V
Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 2019;(5):279-287
Abstract
Polycystic ovary syndrome (PCOS), as the most common endocrine disorder in reproductive-aged women, is recognized by hyperandrogenism and insulin resistance. Selenium (Se) potentially possesses therapeutic effects on PCOS due to antioxidant and insulin-like properties. This systematic review evaluates the potential role of Se in the complications of PCOS. A systematic review was performed on published studies reporting the effects of Se on PCOS. Three major databases including PubMed, Scopus, and Google Scholar were searched until December 2018. A total of 7 human studies and two in vitro studies met the inclusion criteria. Two out of three case-control studies showed that serum Se levels tend to decrease in patients with PCOS. Of four studies that evaluated the impact of Se supplementation on insulin resistance, only one study showed protective effects of Se against insulin resistance. Two out of three studies reported the antioxidant effect of Se. Few studies investigating anti-androgenic effect of Se presented controversial results. There were three studies that evaluated the anti-hyperlipidemic effect of Se, of which two surveys indicated the lowering effects of Se on VLDL and LDL-cholesterol. The reviewed studies confirmed inverse relationships between serum Se levels and some androgenic hormones in PCOS. Se is able to attenuate insulin resistance and dyslipidemia. The available data are currently insufficient to support the protective effects of Se on PCOS.
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3.
The Effects of Selenium Supplementation on Glucose Metabolism and Lipid Profiles Among Patients with Metabolic Diseases: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Tabrizi, R, Akbari, M, Moosazadeh, M, Lankarani, KB, Heydari, ST, Kolahdooz, F, Mohammadi, AA, Shabani, A, Badehnoosh, B, Jamilian, M, et al
Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 2017;(11):826-830
Abstract
This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the effect of selenium administration on glucose metabolism and lipid profiles among patients with diseases related to metabolic syndrome (MetS). We searched the following databases up to May 2017: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as standardized mean difference (MDs) with 95% confidence intervals (95% CI). Five studies were included in the meta-analyses. The results showed that selenium supplementation significantly reduced insulin levels (SMD -0.42; 95% CI, -0.83 to -0.01) and increased quantitative insulin sensitivity check index (QUICKI) (SMD 0.83; 95% CI, 0.58 to 1.09). Selenium supplementation had no beneficial effects on other glucose homeostasis parameters, such as fasting plasma glucose (FPG) (SMD -0.29; 95% CI, -0.73 to 0.15), homeostasis model assessment of insulin resistance (HOMA-IR) (SMD -0.80; 95% CI, -1.58 to -0.03), and lipid profiles, such as triglycerides (SMD -0.42; 95% CI, -0.83 to -0.01), VLDL- (SMD -0.42; 95% CI, -0.83 to -0.01), total- (SMD -0.42; 95% CI, -0.83 to -0.01), LDL- (SMD 0.02; 95% CI, -0.20 to 0.24), and HDL-cholesterol (SMD 0.16; 95% CI, -0.06 to -0.38). Overall, this meta-analysis showed that selenium administration may lead to an improvement in insulin and QUICKI, but did not affect FPG, HOMA-IR, and lipid profiles.
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4.
Selenium Homeostasis and Clustering of Cardiovascular Risk Factors: A Systematic Review.
Gharipour, M, Sadeghi, M, Behmanesh, M, Salehi, M, Nezafati, P, Gharpour, A
Acta bio-medica : Atenei Parmensis. 2017;(3):263-270
Abstract
Selenium is a trace element required for a range of cellular functions. It is widely used for the biosynthesis of the unique amino acid selenocysteine [Sec], which is a structural element of selenoproteins. This systematic review focused on the possible relation between selenium and metabolic risk factors. The literature was searched via PubMed, Scopus, ISI Web of Science, and Google Scholar. Searches were not restricted by time or language. Relevant studies were selected in three phases. After an initial quality assessment, two reviewers extracted all the relevant data, whereas the third reviewer checked their extracted data. All evidence came from experimental and laboratory studies. Selenoprotein P is the best indicator for selenium nutritional levels. In addition, high levels of selenium may increase the risk of metabolic syndrome while the lack of sufficient selenium may also promote metabolic syndrome. selenium supplementation in subjects with sufficient serum selenium levels has a contrary effect on blood pressure, LDL, and total cholesterol. According to the bioavailability of different types of selenium supplementation such as selenomethionine, selenite and selenium-yeast, it seems that the best nutritional type of selenium is selenium-yeast. Regarding obtained results of longitudinal studies and randomized controlled trials, selenium supplementation should not be recommended for primary or secondary cardio-metabolic risk prevention in populations with adequate selenium status.
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5.
Systematic review and meta-analysis shows a specific micronutrient profile in people with Down Syndrome: Lower blood calcium, selenium and zinc, higher red blood cell copper and zinc, and higher salivary calcium and sodium.
Saghazadeh, A, Mahmoudi, M, Dehghani Ashkezari, A, Oliaie Rezaie, N, Rezaei, N
PloS one. 2017;(4):e0175437
Abstract
Different metabolic profiles as well as comorbidities are common in people with Down Syndrome (DS). Therefore it is relevant to know whether micronutrient levels in people with DS are also different. This systematic review was designed to review the literature on micronutrient levels in people with DS compared to age and sex-matched controls without DS. We identified sixty nine studies from January 1967 to April 2016 through main electronic medical databases PubMed, Scopus, and Web of knowledge. We carried out meta-analysis of the data on four essential trace elements (Cu, Fe, Se, and Zn), six minerals (Ca, Cl, K, Mg, Na, and P), and five vitamins (vitamin A, B9, B12, D, and E). People with DS showed lower blood levels of Ca (standard mean difference (SMD) = -0.63; 95% confidence interval (CI): -1.16 to -0.09), Se (SMD = -0.99; 95% CI: -1.55 to -0.43), and Zn (SMD = -1.30; 95% CI: -1.75 to -0.84), while red cell levels of Zn (SMD = 1.88; 95% CI: 0.48 to 3.28) and Cu (SMD = 2.77; 95% CI: 1.96 to 3.57) were higher. They had also higher salivary levels of Ca (SMD = 0.85; 95% CI: 0.38 to 1.33) and Na (SMD = 1.04; 95% CI: 0.39 to 1.69). Our findings that micronutrient levels are different in people with DS raise the question whether these differences are related to the different metabolic profiles, the common comorbidities or merely reflect DS.
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6.
Effects of selenium supplementation on glucose homeostasis and free androgen index in women with polycystic ovary syndrome: A randomized, double blinded, placebo controlled clinical trial.
Mohammad Hosseinzadeh, F, Hosseinzadeh-Attar, MJ, Yekaninejad, MS, Rashidi, B
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2016;:56-61
Abstract
BACKGROUND/OBJECTIVES Insulin resistance (IR) is a main pathophysiologic feature in polycystic ovary syndrome (PCOS) patients which is triggered by elevated oxidative stress in these patients. Selenium, an essential micronutrient, is a major constituent of antioxidant enzymes such as glutathione peroxidase. Recently, decreased plasma selenium concentrations were reported in PCOS patients. So, the present study was carried out in order to assess whether selenium consumption can improve the metabolic response to insulin and reduce the insulin resistance in these women. SUBJECTS/METHODS A total of 53 PCOS patients (diagnosed by Rotterdam criteria), 18-42 years old, participated in this randomized, double-blind and placebo controlled trial for 12 weeks (selenium, n=26; placebo, n=27). The effects of daily administration of 200 μg selenium or placebo on serum glucose, total testosterone (tT), sex hormone binding globulin (SHBG) and free androgen index (FAI) in fasting state were evaluated. RESULTS At the end of the study, insulin resistance was significantly increased in selenium recipients when compared with the placebo group (2.05 ± 0.39 when compared with 1.81 ± 0.25, p=0.017). Also, selenium supplementation resulted in marginally significant increase (p=0.056) in insulin level when compared with the placebo group. There were no statistically significant changes in other study endpoints, when comparing the two groups. CONCLUSION This study showed that selenium supplementation in PCOS patients may worsen insulin resistance in them. Until the results of larger studies become available, indiscriminate consumption of selenium supplements in PCOS patients will warrant caution.
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7.
Metabolic response to selenium supplementation in women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial.
Jamilian, M, Razavi, M, Fakhrie Kashan, Z, Ghandi, Y, Bagherian, T, Asemi, Z
Clinical endocrinology. 2015;(6):885-91
Abstract
OBJECTIVE We are aware of no study examining the effects of selenium supplementation on metabolic profiles of patients with polycystic ovary syndrome (PCOS). This study was conducted to evaluate the effects of selenium supplementation on glucose homeostasis parameters and lipid concentrations in women with PCOS. DESIGN, PATIENTS AND MEASUREMENTS This randomized, double-blind, placebo-controlled trial was conducted among 70 women diagnosed with PCOS and aged 18-40 years old. Participants were randomly divided into two groups to receive 200 μg per day selenium supplements (N = 35) or placebo (N = 35) for 8 weeks. Fasting blood samples were taken at baseline and after 8 weeks intervention to quantify glucose, insulin and lipid concentrations. RESULTS After 8 weeks of intervention, subjects who received selenium supplements had significantly decreased serum insulin levels (-29·83 ± 47·29 vs +9·07 ± 77·12 pmol/l, P = 0·013), homeostasis model of assessment-insulin resistance (HOMA-IR) (-1·15 ± 1·81 vs +0·42 ± 3·09, P = 0·011), homeostatic model assessment-beta-cell function (HOMA-B) (-19·06 ± 30·95 vs +4·55 ± 47·99, P = 0·017) and increased quantitative insulin sensitivity check index (QUICKI) (+0·03 ± 0·04 vs +0·0009 ± 0·05, P = 0·032) compared with placebo. In addition, supplementation with selenium resulted in a significant reduction in serum triglycerides (-0·14 ± 0·55 vs +0·11 ± 0·30 mmol/l, P = 0·025) and VLDL-C concentrations (-0·03 ± 0·11 vs +0·02 ± 0·06 mmol/l, P = 0·025) compared with placebo. CONCLUSIONS In conclusion, 200 microgram per day selenium supplementation for 8 weeks among PCOS women had beneficial effects on insulin metabolism parameters, triglycerides and VLDL-C levels; however, it did not affect FPG and other lipid profiles.
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8.
Selenium, zinc, and copper plasma levels in patients with schizophrenia: relationship with metabolic risk factors.
Vidović, B, Dorđević, B, Milovanović, S, Škrivanj, S, Pavlović, Z, Stefanović, A, Kotur-Stevuljević, J
Biological trace element research. 2013;(1-3):22-8
Abstract
The aim of this study was to determine the plasma selenium (Se), copper (Cu), and zinc (Zn) levels and to evaluate their possible association with metabolic syndrome (MetS) components in patients with schizophrenia. The study group consisted of 60 patients with schizophrenia and 60 sex- and age-matched healthy controls. Anthropometric measurements, blood pressure, and biochemical analysis of fasting blood were performed in all subjects. Patients with schizophrenia had significantly higher plasma Cu concentrations compared with controls (0.97 ± 0.31 vs. 0.77 ± 0.32 mg/L, p = 0.001). The plasma Cu concentration showed a positive correlation with plasma glucose and diastolic blood pressure in the patient groups (r s = 0.263, p < 0.05 and r s = 0.272, p < 0.05, respectively). The plasma Se level correlated positive with MetS score (r s = 0.385, p < 0.01), waist circumference (r s = 0.344, p < 0.05), plasma glucose (r s = 0.319, p < 0.05), and triglyceride concentrations (r s = 0.462, p < 0.001) in patients with schizophrenia. Plasma Zn did not correlate with any of the MetS components. These results suggest that alterations in plasma Cu and Se levels in medicated patients with schizophrenia could be associated with metabolic risk factors.
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9.
Disorders of selenium metabolism and selenoprotein function.
Schweizer, U, Dehina, N, Schomburg, L
Current opinion in pediatrics. 2011;(4):429-35
Abstract
PURPOSE OF REVIEW Inborn errors of metabolism are increasingly recognized as underlying causes in pediatric diseases. Selenium and selenoproteins have only recently been identified as causes of inherited defects. Respective case reports have broadened our understanding of selenoprotein function and their developmental importance. This review presents the characterized defects and tries to attract attention to the spectrum of potential phenotypes. RECENT FINDINGS The characterization of patients with inherited mutations in selenoprotein N has corroborated the physiological importance of selenium for muscle function. Individuals with inherited defects in selenocysteine insertion sequence (SECIS)-binding protein 2 display a syndrome of selenoprotein-related defects including abnormal thyroid hormone metabolism, delayed bone maturation, and other more individual phenotypes. The recent identification of mutations in selenocysteine synthase causing progressive cerebello-cerebral atrophy underlines the central role of selenoproteins in brain development and protection from neurodegeneration. SUMMARY The spectrum of diseases related to inborn defects of selenium utilization, transport, and metabolism is expanding. However, only few examples are already known, resulting from defects in one selenoprotein gene and two genes involved in selenoprotein biosynthesis, respectively. Complex syndromes with impaired muscle function, stunted growth, neurosensory and/or immune defects may point to the involvement of impaired selenium metabolism and selenoprotein function, necessitating specific diagnostic procedures.