Serum Selenium Concentrations Research Articles

Low serum selenium concentration is associated with preeclampsia in pregnant women from Bangladesh

ObjectivesPreeclampsia is a hypertensive disorder of pregnancy which is one of the leading causes of maternal and perinatal mortality and pre-term delivery, especially in low and middle income countries. Selenium is an important constituent of selenoproteins that act as antioxidant and have several metabolic functions. The present study was conducted to determine serum selenium concentration in preeclampsia patients in order to find out the role of selenium in preeclampsia. MethodsThis study was conducted as case-control study with 74 preeclampsia patients as cases whose gestation were ≥20 weeks (52 mild and 22 severe patients) and 118 normotensive pregnant women as controls from same gestational period. Detailed patient history was recorded during routine hospital visits. Serum selenium concentration was determined by using atomic absorption spectroscopy. Independent sample t-test and Pearson’s correlation test were done for the statistical analysis using the statistical software package SPSS, version 16. ResultsOur study found that mean serum concentration of selenium in preeclampsia patients was significantly lower than that of healthy pregnant women (p<0.05). Further analysis for selenium concentration with disease severity explored that selenium concentration was significantly lower in severe preeclampsia in comparison to mild preeclampsia (p<0.05). We found no significant difference for selenium concentration between rural and urban preeclampsia patients (p>0.05). Pearson’s correlation analysis reveals significant negative correlation of selenium with systolic blood pressure (r=−0.419, p=0.001), diastolic blood pressure (r=−0.392, p=0.001), and gestational period (r=−0.218, p=0.001). ConclusionOur study found that preeclampsia patients have decreased serum selenium concentration than the healthy pregnant women.

Serum selenium and ceruloplasmin in nigerians with peripartum cardiomyopathy.

The study aimed to determine if selenium deficiency, serum ceruloplasmin and traditional birth practices are risk factors for peripartum cardiomyopathy (PPCM), in Kano, Nigeria. This is a case-control study carried out in three hospitals, and PPCM patients were followed up for six months. Critically low serum selenium concentration was defined as <70 µg/L. A total of 39 PPCM patients and 50 controls were consecutively recruited after satisfying the inclusion criteria. Mean serum selenium in patients (61.7 ± 14.9 µg/L) was significantly lower than in controls (118.4 ± 45.6 µg/L) (p < 0.001). The prevalence of serum selenium <70 µg/L was significantly higher among patients (76.9%) than controls (22.0%) (p < 0.001). The mean ceruloplasmin and prevalence of socio-economic indices, multiparity, pregnancy-induced hypertension, obesity and twin pregnancy were not different between the groups (p > 0.05). Logistic regression showed that rural residency significantly increased the odds for serum selenium <70 µg/L by 2.773-fold (p = 0.037). Baseline serum levels of selenium and ceruloplasmin were not associated with six-month mortality. This study has shown that selenium deficiency is a risk factor for PPCM in Kano, Nigeria, and is related to rural residency. However, serum ceruloplasmin, customary birth practices and some other characteristics were not associated with PPCM in the study area.

Effects of Selenium Supplementation on Soluble FMS-Like Tyrosine Kinase-1 and Glutathione Peroxidase Levels and the Plasminogen Activator Inhibitor-1: Plasminogen Activator Inhibitor-2 Ratio in Pregnant Women

Background: Preeclampsia is a hypertensive disorder of pregnancy, which is associated with increased maternal and prenatal morbidity and mortality. Oxidative stress associated with preeclampsia may be a consequence of reduced antioxidant defense pathways that might involve inadequate glutathione peroxidase (GPx) levels, perhaps linked to reduced selenium availability. The soluble FMS-like tyrosine kinase-1 (sFlt-1) that contributes to endothelial dysfunction may be partially responsible for the clinical manifestation of preeclampsia. Furthermore, elevated plasminogen activator inhibitor-1 (PAI-1) and decreased plasminogen activator inhibitor-2 (PAI-2) are found in preeclamptic women. Hence, the PAI1: PAI2 ratio maybe a predictor of preeclampsia. Objectives: The objective of this study was to evaluate the effects of selenium supplementation on sFlt-1, GPx activity and PAI1: PAI2 ratio in pregnant women. Materials and Methods: A total of 125 high-risk pregnant women (with a familial history of hypertension, hyperlipidemia and other risk factors for preeclampsia) in the first trimesters of pregnancy were assigned to either selenium (n = 61) or placebo (n = 64) groups. The selenium group received 100 μg/day of selenium as a selenium-yeast tablet for six months. The placebo group received a placebo yeast tablet for the same period. At the beginning of the trial and at the end, blood samples were collected and the levels of sFlt-1, PAI-1, PAI2 and GPx were measured in blood serum and plasma. Results: Serum selenium concentrations were raised in the selenium group (P < 0.001) from the first to the third trimester, but was unchanged in the placebo group (P = 0.85). The results showed that sFlt-1 had significantly increased in both groups by the end of the gestation period, and selenium supplementation had no significant effect on the selenium group (P = 0.51). However, GPx activity was significantly increased in the selenium treatment group after supplementation compared to the control group (P < 0.001). The PAI1: PAI2 ratio was not significantly different between the two groups (P = 0.44). Conclusions: Selenium intake during the second and third trimester of pregnancy increased GPx activity but did not have a significant effect on serum sFlt-1 levels or the ratio of PAI1: PAI2 in the serum.

Impact of the Nationwide Intravenous Selenium Product Shortage on the Development of Selenium Deficiency in Infants Dependent on Long‐Term Parenteral Nutrition

For patients dependent on parenteral nutrition (PN), selenium must be supplemented intravenously. A nationwide intravenous selenium shortage began in April 2011. The impact of this shortage on PN-dependent infants was evaluated by examining the provision of selenium, development of biochemical deficiency, and costs associated with the shortage. This single-center, retrospective study included PN-dependent infants aged ≤1 year who weighed ≤30 kg, received PN for ≥1 month, and had ≥1 serum selenium measurement. The primary outcome was the incidence of biochemical selenium deficiency. Secondary outcomes included severity of biochemical deficiency, clinical manifestations, costs, and relationship between serum selenium levels and selenium dose. The average selenium dose decreased 2-fold during the shortage (2.1 ± 1.2 µg/kg/d; range, 0.2-4.6 µg/kg/d) versus the nonshortage period (3.8 ± 1 µg/kg/d; range, 2.4-6 µg/kg/d; P < .001). A linear relationship between serum selenium concentration and selenium dose was observed (r(2) = 0.42), with a dose of 6 µg/kg/d expected to result in normal serum levels in most cases. Similar proportions of patients developed biochemical deficiency in both groups: shortage period, 59.1%; nonshortage, 66.7%; P = .13. The severity of biochemical deficiency was similar between groups. A significant increase in incremental cost during the shortage was observed. This is the first study examining the impact of the intravenous selenium shortage on PN-dependent infants. Both groups exhibited similarly high incidences of biochemical selenium deficiency, suggesting higher empiric doses may benefit this population. However, ongoing shortages limit the ability to provide supplementation.

Manganese and selenium concentrations in umbilical cord serum and attention deficit hyperactivity disorder in childhood

Existing evidence on the effects of manganese and selenium during fetal life on neurodevelopmental disorders is inadequate. This study aims to investigate the hypothesized relationship between fetal exposure to manganese and selenium and attention deficit hyperactivity disorder (ADHD) diagnosis in childhood. Children born between 1978 and 2000 with ADHD (n=166) were identified at the Department of Child and Adolescent Psychiatry in Malmö, Sweden. Controls from the same region (n=166) were selected from the Medical Birth Register and were matched for year of birth and maternal country of birth. Manganese and selenium were measured in umbilical cord serum. The median cord serum concentrations of manganese were 4.3μg/L in the cases and 4.1μg/L in the controls. The corresponding concentrations of selenium were 47 and 48μg/L. When the exposures were analyzed as continuous variables no associations between cord manganese or selenium concentration and ADHD were observed. However, children with selenium concentrations above the 90th percentile had 2.5 times higher odds (95% confidence interval 1.3–5.1) of having ADHD compared to those with concentrations between the 10th and 90th percentiles. There was no significant interaction between manganese and selenium exposure (p=0.08). This study showed no association between manganese concentrations in umbilical cord serum and ADHD. The association between ADHD diagnoses in children with relatively high cord selenium was unexpected and should be interpreted with caution.

Optimal Serum Selenium Concentrations Are Associated with Lower Depressive Symptoms and Negative Mood among Young Adults1–3

Background: There is evidence that low, and possibly high, selenium status is associated with depressed mood. More evidence is needed to determine whether this pattern occurs in young adults with a wide range of serum concentrations of selenium.Objective: The aim of this study was to determine if serum selenium concentration is associated with depressive symptoms and daily mood states in young adults.Methods: A total of 978 young adults (aged 17–25 y) completed the Center for Epidemiological Studies–Depression scale and reported their negative and positive mood daily for 13 d using an Internet diary. Serum selenium concentration was determined by inductively coupled plasma mass spectrometry. ANCOVA and regression models tested the linear and curvilinear associations between decile of serum selenium concentration and mood outcomes, controlling for age, gender, ethnicity, BMI, and weekly alcohol intake. Smoking and childhood socioeconomic status were further controlled in a subset of participants.Results: The mean ± SD serum selenium concentration was 82 ± 18 μg/L and ranged from 49 to 450 μg/L. Participants with the lowest serum selenium concentration (62 ± 4 μg/L; decile 1) and, to a lesser extent, those with the highest serum selenium concentration (110 ± 38 μg/L; decile 10) had significantly greater adjusted depressive symptoms than did participants with midrange serum selenium concentrations (82 ± 1 to 85 ± 1 μg/L; deciles 6 and 7). Depressive symptomatology was lowest at a selenium concentration of ∼85 μg/L. Patterns for negative mood were similar but more U-shaped. Positive mood showed an inverse U-shaped association with selenium, but this pattern was less consistent than depressive symptoms or negative mood.Conclusions: In young adults, an optimal range of serum selenium between ∼82 and 85 μg/L was associated with reduced risk of depressive symptomatology. This range approximates the values at which glutathione peroxidase is maximal, suggesting that future research should investigate antioxidant pathways linking selenium to mood. This trial was registered with the Australian New Zealand Clinical Trials Registry as ACTRN12613000773730.

Pharmacological Treatment may Impair Mineral Status in Blood

Hematological and biochemical blood parameters are rather stable in healthy subjects. However, there are many factors that can influence mineral status in blood, including diseases, diet, and drugs. It has been found that several medicines can alter both mineral concentrations and other mineral-status-related parameters in blood. In experimental and human studies, it has been shown that hypotension therapy disturbs zinc status in the body [1]. Some of our results suggest that indapamide and amlodipine treatment can decrease zinc concentration in serum and erythrocytes. Moreover, the decrease in zinc is accompanied by an increase in glucose serum levels [2]. In our experimental study, we observed that treatment with indapamide and amlodipine was associated with increased red blood cell counts and hematocrit values in the serum of spontaneously hypertensive rats [3]. In patients, high hematocrit could reflect the increase in red blood cell mass resulting from the reduction in plasma volume due to treatment with thiazide-type diuretics. Long-term therapy with captopril and enalapril may lead to zinc depletion in erythrocytes and monocytes. Preliminary data suggest that indapamide can cause a slight elevation in blood calcium levels. Several results indicate that loop diuretics, especially furosemide, reduce serum calcium and magnesium levels. It has also been observed that beta-blockers may induce hypocalcemia and hypomagnesemia [4]. Antiepileptic therapy with valproic acid may cause abnormalities in serum copper concentration. Some authors have found that therapy with valproic acid can diminish copper levels in erythrocytes and serum in epileptic patients [5,6]. Nonsteroidal anti-inflammatory drugs, when taken regularly, may cause bleeding from the gastrointestinal tract and iron loss with the blood. The use of aspirin and other medicines belonging to this group of drugs may therefore increase the risk of iron deficiency, which can be identified as a low hemoglobin and serum ferritin concentration [4,7]. In patients with digoxin therapy, a decrease in intracellular magnesium levels and a relatively low level of magnesium in serum were observed [8]. The long-term use of corticosteroids, cisplatin, cyclosporine is also associated with a depletion of magnesium in the serum and an increase in the risk of hypomagnesemia [4,9]. It is known that dietary restriction may impair mineral status; however, pharmacological treatment of obesity may also alter the concentration of minerals in the blood. In our clinical study, we found that 12 weeks of sibutramine therapy decreases zinc and increases magnesium concentrations in the serum, leading to mineral imbalances in obese women [10]. Oral contraceptives (OCs) are among the most commonly used drugs in developed countries. One of the side effects of this group of drugs is their influence on the mineral status in women. In several studies, it was observed that the use of oral contraceptives is associated with decreased zinc, magnesium, and selenium serum concentrations, and with increased copper levels in serum. It has also been found that oral contraceptives can increase ferritin and iron levels, TIBC, and mean corpuscular hemoglobin in serum, while decreasing red blood cells and hematocrit in whole blood in women. The results of human studies suggest that the effect of OCs on mineral status can vary with the form, dose, concomitant agents, and patient characteristics [4,11]. The mechanisms behind the observed interactions between drugs and minerals cannot always be explained. Some may be associated with changes in the excretion of minerals in the urine. Drugs may also influence the absorption and/or distribution of minerals in the body [4 ]. In conclusion, many drugs influence mineral status in the blood. Pharmacological treatment may require the monitoring of mineral concentrations in blood. Moreover, the interpretation of the results of morphological and biochemical analyses in blood requires a consideration of the drugs being used by the patient.

Micronutrient status in female university students: iron, zinc, copper, selenium, vitamin B12 and folate.

Young women are at an increased risk of micronutrient deficiencies, particularly due to higher micronutrient requirements during childbearing years and multiple food group avoidances. The objective of this study was to investigate biomarkers of particular micronutrients in apparently healthy young women. Female students (n = 308; age range 18–35 year; Body Mass Index 21.5 ± 2.8 kg/m2; mean ± SD) were recruited to participate in a cross-sectional study. Blood samples were obtained from participants in the fasted state and analysed for biomarkers of iron status, vitamin B12, folate, homocysteine, selenium, zinc, and copper. The results show iron deficiency anaemia, unspecified anaemia, and hypoferritinemia in 3%, 7% and 33.9% of participants, respectively. Low vitamin B12 concentrations (<120 pmol/L) were found in 11.3% of participants, while 4.7% showed sub-clinical deficiency based on serum methylmalonic acid concentrations >0.34 μmol/L. Folate concentrations below the reference range were observed in 1.7% (serum) or 1% (erythrocytes) of participants, and 99.7% of the participant had erythrocyte-folate concentrations >300 nmol/L. Serum zinc concentrations <10.7 μmol/L were observed in 2% of participants. Serum copper and selenium concentrations were below the reference range in 23% and 11% of participants, respectively. Micronutrient deficiencies including iron and vitamin B12, and apparent excess of folate are present in educated Australian female students of childbearing age, including those studying nutrition. The effects of dietary behaviours and food choices on markers of micronutrient status require further investigation.

Pre-antiretroviral therapy serum selenium concentrations predict WHO stages 3, 4 or death but not virologic failure post-antiretroviral therapy.

A case-cohort study, within a multi-country trial of antiretroviral therapy (ART) efficacy (Prospective Evaluation of Antiretrovirals in Resource Limited Settings (PEARLS)), was conducted to determine if pre-ART serum selenium deficiency is independently associated with human immunodeficiency virus (HIV) disease progression after ART initiation. Cases were HIV-1 infected adults with either clinical failure (incident World Health Organization (WHO) stage 3, 4 or death by 96 weeks) or virologic failure by 24 months. Risk factors for serum selenium deficiency (<85 μg/L) pre-ART and its association with outcomes were examined. Median serum selenium concentration was 82.04 μg/L (Interquartile range (IQR): 57.28–99.89) and serum selenium deficiency was 53%, varying widely by country from 0% to 100%. In multivariable models, risk factors for serum selenium deficiency were country, previous tuberculosis, anemia, and elevated C-reactive protein. Serum selenium deficiency was not associated with either clinical failure or virologic failure in multivariable models. However, relative to people in the third quartile (74.86–95.10 μg/L) of serum selenium, we observed increased hazards (adjusted hazards ratio (HR): 3.50; 95% confidence intervals (CI): 1.30–9.42) of clinical failure but not virologic failure for people in the highest quartile. If future studies confirm this relationship of high serum selenium with increased clinical failure, a cautious approach to selenium supplementation might be needed, especially in HIV-infected populations with sufficient or unknown levels of selenium.

Effect of selenium on the development of selected indicators of fertility in dairy cows

Aim: The aim of this study was to determine selenium (Se) concentration in the blood serum of dairy cows and to establish its influence on the level of production and reproduction traits. Materials and Methods: The study was performed on the farm located in Western Pomerania - Poland and involved 120 cows, which were selected using the analog method on the basis of their physiological state, lactation number, milk yield, age, and genotype. The following indices were analyzed in individual groups: Calving interval, gestation interval, insemination index, standstill of placenta. Se concentration in the blood serum was determined with the spectrofluorometric method. Results: The mean serum Se concentration was in cows 0.038 μg/ml. The use of Se preparations has raised fertility, which was documented statistically. Conclusion: The study revealed that the problem of Se deficiency is still present in some dairy cattle herds in Western Pomerania - Poland.

Infl uence of selenium deficiency on neural tube defects

Objective: As for the role of selenium on human fetal development, a little data is available in literature. The purpose of this manuscript was to study the influence of selenium on neural tube defects. This study will be helpful in planning strategies for prevention of neural tube defects.Methodology: After collection of the venous blood the same was immediately centrifuged and after immediate centrifugation, the clear serum was transferred to deionized plastic vials, stored and frozen at –20º C until determination of the analysis was carried out. The selenium levels as ng/ml were determined on GBC 932 spectrophotometer by fluorometery.Results: The mean maternal blood serum and cell mass concentrations in NTD group (306.4 ± 10.95 ng/ml, 192.44 ± 6.12 ng/ml, 165.8 ± 16.99 ng/g respectively) were significantly lower than those of control mothers (363.75 ± 17.1 ng/ml, 242.34 ± 15.7 ng/ml, 260.0 ± 20.57 respectively). A significant decrease in concentration of selenium in newborns with NTD (298.4 ± 12.3 ng/ml, 96.3 ± 7.15 ng/ml, 139.8 ± 27.5 ng/g respectively) as compared with healthy babies (358.1 ± 16.11 ng/ml, 122.44 ± 6.03 ng/ml, 268.6 ± 31.37 ng/g respectively).Conclusion: Selenium deficiency in mothers during pregnancy thought to be one of the factors responsible for NTDs. However, the lowered selenium concentrations in blood, serum and cell mass can be secondary cause of an abnormal pregnancy and didn’t contribute to its production. More investigations on selenium status in mothers during antenatal period, especially in prenatal development and antenatal selenium status including normal babies and NTD babies are required.DOI: http://dx.doi.org/10.3126/ajms.v6i2.11151Asian Journal of Medical Sciences Vol.6(2) 2015 62-65

The association between serum selenium and gestational diabetes mellitus: A systematic review and meta-analysis

BackgroundResults of the studies about association between serum selenium concentration and gestational hyperglycemia are inconsistent. Some studies have demonstrated that women with gestational diabetes mellitus (GDM) have lower Se concentrations while contrary results are reported in other studies. AimThe aim of this study is to compare the serum Se concentration in women with GDM and normoglycemic pregnant women via a systematic review and meta-analysis. MethodsA computerized literature search on four databases (PubMed, Cochrane register of control trials, Scopus and Google scholar) was performed from inception through August 2013. Necessary data were extracted and random effects model was used to conduct the meta-analysis. ResultsSix observational studies (containing 147 women with GDM and 360 normoglycemic pregnant women) were found, which had compared serum Se concentration in women suffering from GDM with normal pregnant ones. Our meta-analysis revealed that serum Se concentration was lower in women with GDM compared to normoglycemic pregnant women (Hedges=−1.34; 95% CI: −2.33 to −0.36; P<0.01). Stratified meta-analysis demonstrated that concentration of Se in the sera of women with GDM was lower than normal pregnant women both in second and third trimesters, but the result was not significant in second trimester (second trimester: Hedges=−0.68; 95% CI: −1.60−0.25; P=0.15, third trimester: Hedges=−2.81; 95% CI: −5.21 to −0.42; P<0.05). It was also demonstrated that serum Se status was lower in pregnant women with impaired glucose tolerance (IGT) compared to normoglycemic pregnant women (Hedges=−0.85; 95% CI: −1.18 to −0.52). ConclusionThe available evidences suggest that serum Se concentration is significantly lower in pregnant women with gestational hyperglycemia compared to normal pregnant women.

SLC30A3 and SEP15 gene polymorphisms influence the serum concentrations of zinc and selenium in mature adults

Because of their numerous roles in several biological processes, zinc and selenium are the most commonly studied micronutrients in the elderly. Therefore, we hypothesized that the polymorphisms in the genes that are responsible for the transport of zinc and selenium may have a genotype-dependent effect on the serum concentration of these micronutrients. The objective of this study was to determine the effects of solute carrier family 30 member 3 (SLC30A3) and 15-kd selenoprotein (SEP15) polymorphisms on zinc and selenium concentrations, respectively, in the serum. This cross-sectional study included 110 individuals who were aged 50 years or older. Serum micronutrient concentrations were determined by flame atomic absorption spectrophotometry (for zinc) and by atomic absorption spectrophotometry with a graphite furnace (for selenium). The single-nucleotide polymorphisms, rs73924411 and rs11126936 of the SLC30A3 gene and rs5859, rs5854, and rs561104 of the SEP15 gene, were examined by real-time polymerase chain reaction. Regarding rs11126936, the serum zinc concentration was lower in CC homozygotes (0.75 ± 0.31 mg/L) than in A carriers (0.89 ± 0.28 mg/L, P = .016). Concerning rs561104, the serum selenium concentration was higher in CC homozygotes (5.65 ± 1.11 μg/dL) compared with T carriers (4.88 ± 1.25 μg/dL, P = .044). Our results demonstrate the influence of SLC30A3 and SEP15 gene polymorphisms on the serum concentrations of zinc and selenium, respectively. The effects of these associations should be further investigated to help elucidate the modes of action of trace elements and to identify biomarkers, which could ultimately define the optimal intake of these micronutrients at the molecular level. More research must be performed before the roles of these polymorphisms in the serum concentrations of zinc and selenium can be fully understood.

Serum and urinary selenium levels in obese children: A cross-sectional study

ObjectiveTo determine serum and urinary selenium (Se) levels in children with and without obesity, and to assess if Se influences the risk of obesity. Subjects and methodsHigh-resolution-continuum source-atomic absorption spectrometry (HR-CS-AAS) was used to determine the content of Se in 80 children (age 6–17; 40 boys, 40 girls). Correlations between variables were tested with the use of Spearman's correlation coefficient. U Mann–Whitney test was applied to assess the difference of Se contents in samples. Measured metabolic risk factors (blood pressure, glucose level, triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol), age, gender, and BMI were correlated. Logistic regression models were fitted to identify predictors of obesity interacting with selenium content in serum and urine, separately. ResultsObese children, regardless of gender, had lower Se content. Se level in serum (p=0.001, OR 0.74, 95%CI 0.62–0.88) and total cholesterol (p=0.001, OR 1.19, 95%CI 1.08–1.31) were the independent factors significantly influencing the risk of obesity in children. Two separate models were observed for Se in urine: (i) Se level (p<0. 0001, OR 0.70, 95%CI 0.58–0.84) and glucose level (p<0.0001, OR 1.22, 95%CI 1.10–1.35), and (ii) Se level (p=0.002, OR 0.60 95%CI 0.43–0.83) and total cholesterol level (p=0.003, OR 1.16, 95%CI 1.05–1.28). ConclusionThe current study suggests a possible role of Se in obesity. Further research needs to be performed to check if obese children are an at-risk group for Se deficiency.

Serum selenium and glutathione peroxidase concentrations in healthy Iranian subjects

BACKGROUND AND AIM: We have investigated the association between serum selenium and GPx concentrations, demographic characteristics, anthropometric features, fasting lipid profile and blood glucose levels, in healthy subjects. METHODS: Serum selenium was measured by atomic absorption spectrometry in 197 healthy subjects. Serum glutathione peroxidase, fasting lipid profile, and blood glucose levels were also determined for each subject. Anthropometric features including blood pressure and body mass index were determined using standard procedures. RESULTS: The mean serum selenium in the whole subjects group was 116 ± 27.73g/l (range 44–209g/l). Serum Selenium and GPX concentration did not vary significantly with gender and smoking habit. Significant differences were observed in serum selenium and GPx concentration with age (P < 0.05 and P < 0.02 respectively). Obese subjects had significantly lower serum concentrations of GPx (r = 0.281, P = 0.01). Serum GPx concentrations were inversely related to weight (P = 0.01), systolic blood pressure (P < 0.01), fasting blood sugar (P < 0.01), serum low-density lipoprotein-cholesterol (LDL-C) (P = 0.01), serum triglycerides (P < 0.01), and positively associated with fasting total cholesterol levels. The corresponding predictors for serum selenium level were diastolic blood pressure (P < 0.05) and serum triglycerides level (P = 0.05), which were inversely related. CONCLUSION: Serum concentration of selenium in an Iranian healthy population is higher than most countries however, similar to the US and UK. Moreover, serum selenium and GPx concentrations appear to be influenced by physiological factors including age. Their serum concentrations were also associated with coronary risk factors, including serum total cholesterol and serum triglycerides levels.

Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

Antioxidant status in blood of obese children: the relation between trace elements, paraoxonase, and arylesterase values.

Obesity is known to lead to complications involving several systems. The basic mechanism in obesity-related complications is chronic inflammation and increased oxidative stress. Trace element levels in obese children may vary due to poor nutritional habits. The purpose of this study was to investigate the relation between serum paraoxonase (PON1) and arylesterase (ARE) levels, markers of the oxidant-antioxidant balance in the body, and serum zinc (Zn), copper (Cu), manganese (Mn), and selenium (Se) concentrations in obese children. Fifty-seven overweight patients aged 6-17 and 48 age- and sex-matched healthy children were included in the study. Serum PON1 and ARE activity levels were measured, together with Cu, Zn, Mn, Se, total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, very low-density lipoprotein, glucose, aspartate amino transferase, and alanine amino transferase levels. PON1 and ARE activity levels were significantly lower in obese patients compared to those in healthy individuals (P < 0.05). Various changes were determined in Cu, Zn, Mn, and Se levels between the study and control groups (P < 0.05). In terms of the relation between trace elements and PON1 and ARE levels, a significant positive correlation was determined between serum Se and PON1 levels in the study group (P < 0.05, r = 0.31). No significant correlation was determined between other trace element levels and PON1 and ARE levels (P > 0.05). In conclusion, the detection in our study of a positive correlation between Se and PON1 levels in obese children may be significant in terms of showing a relation between Se and antioxidant systems in obese children.

Effects of injectable fat-soluble vitamins and selenium on serum status in young beef calves

Crossbred beef calves (age 3 to 20 days) were used to determine effects of injectable vitamins on serum concentrations of selenium, vitamin A (retinol), and vitamin E (alpha-tocopherol). Spring-born calves were assigned to 1 of 4 treatments: (1) no treatment (Control, n=10); (2) 4 mL of a product containing selenium and vitamin E (SE, n=10); (3) 5 mL of a product containing vitamin E, vitamin A, and vitamin D (EAD, n=10); or (4) 4 mL SE and 5 mL EAD (Both, n=10). Blood samples were taken from calves immediately prior to (day 0) and 48 hours after treatment, and from their dams on day 0. Concentrations of selenium, vitamin A, and vitamin E in the dams were 112.8 ng/mL, 0.21 æg/mL, and 2.84 æg/mL, respectively. Calves administered SE (70.3 ng/mL) or Both (72.9 ng/mL) had greater (P&lt;0.05) concentrations of selenium on day 2 compared with Control (57.2 ng/mL) or EAD (56.0 ng/mL) calves. Calves administered EAD (0.21 æg/mL) or Both (0.22 æg/mL) had greater (P&lt;0.05) concentrations of vitamin A compared with SE (0.17 æg/mL) or Control calves (0.15 æg/mL). Calves administered EAD (13.8 æg/mL) or Both (15.0 æg/mL) had greater (P&lt;0.05) concentrations of vitamin E compared with SE (6.2 æg/mL) or Control calves (3.4 æg/mL). Administration of injectable EAD increased serum concentration of vitamin A and vitamin E in young beef calves, whereas SE increased concentrations of selenium. Neither duration nor clinical significance of increased concentrations of vitamins and selenium were investigated.

Serum selenium concentration and glutathione peroxidase activity and selenium content in testes of Polish Konik horses from selenium--deficient area in North-Western Poland.

The aim of this study was to determine serum selenium concentrations in Polish Konik horses residing in the Odra Delta Nature Park (Poland) and to evaluate the activity of glutathione peroxidase and Se content in testes of this horse breed. In over 95% of cases, serum Se concentration was below the optimal range, and none of the horses examined was deficient in this trace element. The lack of Se deficiency in the animals examined suggests however, that the Polish Konik horses have a natural ability to the optimal use of nutrients available in their life area. Testicular content of Se and GSHPx activity in the colts was higher than those found in stallions, and a positive relationship between these antioxidants was demonstrated. The differences in Se contents and GSHPx activities in testes between colts and stallions suggest that selenoenzymes play important roles during the puberty of male horses.

Impact of selenium supplements on health of mammary gland in early lactation period

The period before parturition in high producing dairy cows is accompanied by increased demands for energy that can't be provided with food, and cows entering a negative energy balance, which leads to various metabolic disorders. Adding trace elements in cow' s food is achieved by improving the health of the cows. Selenium as a trace element has essential importance in the proper functioning of the mammary gland of cows. The values of the concentration of selenium in milk serum in high-producing dairy cows are 2-60 mg / l. It was experimentally proved that the application of selenium has positive impact reducing the number of somatic cells in milk. From the results it can be seen that adding supplements of selenium in cows food during early lactation period can positively affect the health of the mammary gland in highly productive cows, and consequently on their health and milk production.