Selenium Levels Research Articles

Occupational Exposure to Lead Increases Inflammation that Causes Cardiovascular Disease and Lowers Selenium levels

Occupational Exposure to Lead Increases Inflammation that Causes Cardiovascular Disease and Lowers Selenium levels

Serum Selenium Levels and Their Relationship with Insulin Resistance in Individuals with Polycystic Ovary Syndrome.

Growing evidence indicates a potential link between polycystic ovary syndrome (PCOS) and selenium (Se) levels. This study aims to assess Se concentrations in Saudi women with and without PCOS and to explore the relationships between Se levels, insulin resistance (IR), adiponectin, and lipid markers. We randomly recruited 197 women aged 18 to 40, both with and without PCOS, for this age-matched case-control study. The PCOS participants were categorized into three groups based on their Se levels. All participants underwent interviews, and their anthropometric measurements and blood samples were collected for further analysis of biochemical variables. There was a notable difference between the two groups studied across all biochemical variables. Specifically, fasting blood glucose, insulin, the homeostasis model assessment (HOMA-IR) index, total cholesterol, low-density lipoprotein cholesterol, and triglycerides were significantly higher in the PCOS group compared to the control group (p < 0.01). Conversely, Se, high-density lipoprotein cholesterol, and adiponectin levels were significantly lower in women with PCOS than in their age-matched controls (p < 0.01). HOMA-IR was identified as the sole independent predictor of serum Se levels, explaining 17.2% of the variability in its circulating levels (β = - 0.57; 95% CI: - 0.96 to - 0.18, p = 0.004). The findings reveal that women with PCOS have lower serum Se levels compared to the controls. Furthermore, the results confirm a correlation between Se levels and insulin resistance.

Selenium and Graves’ Disease

Selenium, a trace element present in specific selenoproteins, is essential for thyroid hormone metabolism. Selenium is also an antioxidant with immunosuppressive properties and may help in managing thyroid autoimmune diseases, including Graves’ (GD) hyperthyroidism and Graves’ ophthalmopathy (GO). There were 320 clinical studies related to selenium and thyroid published in English and French between January 1, 2000, and June 1, 2023. Our focus was to identify studies reporting levels of serum selenium in patients with GD and studies that assessed the effect of selenium supplementation on outcomes of GD hyperthyroidism and GO. We also reviewed 20 systematic reviews and meta-analyses of randomized controlled trials that reported selenium levels in GD and the effects of supplementation on GD and GO outcomes. Our review showed that patients with GD had serum selenium levels lower than those of various control patients. In the short-term, a selenium supplement to antithyroid drugs showed benefit for GD hyperthyroidism in most studies, but long-term benefits and positive effects on remission rate were unclear. Some studies did not show benefit. The benefits may depend on baseline selenium deficiency. Two randomized controlled trials showed positive effects of supplementation for mild GO; however, studies about moderate and severe GO are still needed. There is evidence for benefit with short-term selenium supplementation for GD hyperthyroidism, but controlled studies are needed to assess long-term benefits, and benefits in selenium-sufficient areas.

Day-to-Day Fluctuation in Micronutrient Content in Human Milk Relative to Maternal Diet.

The impact of daily variations in habitual maternal intake on human milk (HM) composition has been poorly studied. We aimed to investigate the associations between day-to-day fluctuation in the micronutrient concentration in HM and daily maternal diet. To this end, an observational longitudinal study was carried out. A total of 143 lactating women each compiled a five-day weighed dietary record and concomitantly expressed milk for four successive days. Maternal daily intakes of micronutrients and food groups were analyzed. Free thiamine, free riboflavin, nicotinamide, pantothenic acid, pyridoxal, folic acid, cobalamin, ascorbic and dehydroascorbic acids, retinol, alpha- and gamma-tocopherol, cholecalciferol, and calcidiol in HM were determined for each of the four investigated days. A longitudinal data analysis with generalized estimating equation models was performed. For each daily serving of meat, fish, and eggs, total vitamin D3 levels increased by 243.2 pg/mL (p = 0.027) and selenium levels increased by 0.16 ppb (p = 0.031) in HM. For every 1 mg/day of riboflavin supplementation, free riboflavin levels in HM increased by 28.6 mcg/L (p = 0.019). Pyridoxal levels in HM increased by 6.3 mcg/L per 1 mg/day of vitamin B6 supplementation (p = 0.001), and by 2 mcg/L per daily fruit ration (p = 0.016). In conclusion, we were able to quantify the impact of the usual day-to-day variations in the diet and in the intake of commonly used supplements on the fluctuation of vitamin D, free riboflavin, pyridoxal, and selenium concentration in the milk of lactating women.

Double-sided effect of selenium on blood lipids: A dose-response meta-analysis

Abstract Background Selenium, a trace element with both nutritional and toxicological properties, has been suggested to increase cardiovascular risk, particularly concerning diabetes and blood pressure levels. However, the impact of selenium exposure on the risk of dyslipidemia remains uncertain. This meta-analysis explored the shape of the relation between selenium exposure and its effects on lipid profiles in the most relevant experimental human studies, randomized controlled trials (RCTs). Materials and methods The review was registered in PROSPERO (ID: CRD42022380432). Through a bibliographic search conducted on PubMed, Web of Science, Embase, and the Cochrane Library, we identified RCTs investigating the impact of selenium supplementation on lipid profile. We then compared the results between intervention and control groups and, whenever possible, evaluated the non-linear relationship using a dose-response approach. Results We could include 26 RCTs involving different populations, i.e. healthy individuals, pregnant women, and subjects with health conditions such as cardiovascular diseases and Alzheimer’s dementia. Study endpoints were levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides. Our dose-response analysis indicated that selenium supplementation exceeding 200 µg/day adversely affected total cholesterol, HDL, and triglyceride levels. Hence, a threshold for such a detrimental effect of selenium was observed on total and HDL cholesterol and triglycerides, while opposite and inconsistent results emerged for levels below 200 µg/day and for LDL-cholesterol. Blood selenium levels at the end of the studies were positively associated with adverse effects on all endpoints. Conclusions This first dose-response meta-analysis of the effects of selenium on blood lipids highlights the potentially adverse effects of this trace element, in the amount and the chemical forms used in the trials. Key messages • Elevated selenium levels correlated with adverse effects on lipid profile. • Selenium doses exceeding 200 µg/day showed adverse effects on total and HDL cholesterol and triglycerides levels.

Ccdc152 is not necessary for male fertility, but contributes to maintaining sperm morphology.

Selenoprotein P (SeP) is synthesized in the liver and plays a vital role in maintaining selenium homeostasis via transport throughout the body. Previous studies have shown that SeP-deficient mice have severely reduced expression of selenoproteins essential for testicular function, leading to male infertility. We previously reported that the high expression of Ccdc152 in hepatocytes acts as a lncRNA, suppressing SeP expression in the liver. Ccdc152 reduces SeP translation by binding to SeP mRNA and decreasing its interaction with SECIS-binding protein 2. Although Ccdc152 is highly expressed in testes, its function remains unclear. Therefore, this study aimed to elucidate the role of Ccdc152 in the testes. Using the CRISPR/Cas9 system, we generated mice lacking all exons of Ccdc152 and found that SeP expression levels in the liver and plasma, as well as overall selenium homeostasis, remained unchanged. No significant differences were observed in the expression of glutathione peroxidase 1/4 or level of selenium in the testes. Subsequent investigation of the impact on male reproductive function revealed no abnormalities in sperm motility or Mendelian ratios of the offspring. However, a slight decrease in testicular weight and an increased rate of sperm malformations in the epididymis were observed. RNA-seq and pathway analyses identified the reduced expression of multiple genes related to kinesin and reproductive pathways. Based on these findings, Ccdc152 may not be essential for male reproductive function, but it may enhance reproductive capabilities by maintaining the expression of genes necessary for reproduction.

Effects of foliar application of two forms of selenium on anatomic features of Thymus daenensis Celak

To investigate selenium effects on anatomic features of Thymus daenensis, three concentrations of bulk and nanoparticles of the element (2, 4 and 8 ppm) along with distilled water, as a control, were sprayed on foliar of young seedlings of the plant species for six times with 2 weeks intervals. Transverse sections of stems, roots and leaves of the treated plants were manually produced and stained by Carmine and Methylene blue. Average of 5 readings was recorded for each treatment on several anatomic traits. Statistical analysis of the data revealed that the effects of selenium treatments were significantly different, at 1% of probability, on all of the studied anatomic characters. The first level of nanoparticles showed the most positive effects on several root characteristics. The highest level of selenium nanoparticles (8 ppm) showed the most positive effects on stem diameter and stem vascular cylinder diameter. The last two levels of nanoparticles had similar and the largest effect on stem epidermis thickness. The lowest level of bulk selenium (2 ppm) showed the most increment on leaf characteristics. Application of a low concentration of selenium by foliar spraying on young plants of the species is suggested for more vegetative growth and higher photosynthetic efficiency

Beneficial Effects of Selenium and Its Supplementation on Carcinogenesis and the Use of Nanoselenium in the Treatment of Malignant Tumors.

Selenium was recognized as a non-toxic element in the second half of the 20th century. Since then, the positive impact of selenium on the functioning of the human body has been noticed. It has been shown that low levels of selenium in the body are significantly associated with a higher risk of developing cancer. Selenium acts as an antioxidant and inhibits the proliferation of cancer cells. It has been shown that selenium supplementation may contribute to reducing the risk of DNA mutations and carcinogenesis. Nanomedicine has become very helpful in both the diagnosis and treatment of cancer. Due to its anticancer properties, selenium is used in nanotechnology as selenium nanoparticles.

Different characteristics of the soil in marmot habitats might be one of the factors that influcting Yersinia pestis prevalent in which than pikas.

Marmots are recognized as host animals for plague caused by Yersinia pestis infection. It is unclear that why plague prevalent in marmot rather than other rodents like pikas in the same habitats. This study aims to analyze the differences of the soil characteristics around marmots and pikas burrows to explore the soils factors impacting on different epidemic intensities of Yersinia pestis in these two rodents. Soil samples were collected from within and around marmot and pika burrows, as well as from the nearby areas not inhabited by them and Chinese baseline soil properties as control groups, in the Qilian Mountains of Gansu Province, China. The physicochemical properties and the bacterial 16S rRNA were measured to analyze the characteristics of soils from different groups. Subsequently, the data were analyzed using R studio. The analysis revealed that marmot habitats exhibited distinct soil characteristics, including lower organic matter and alkaline hydrolyzed nitrogen, but higher electrical conductivity and total soluble salts. And soil in marmot areas tended to have higher concentrations of nickel, chromium, and iron, also lower levels of zinc and selenium. Additionally, the alpha diversity of soil microorganisms in marmot habitats was significantly low. Simultaneously, redundancy analysis was conducted, which showed that the low alpha diversity of marmot-soil was influenced by its physicochemical properties. The alpha diversity of the soil was positively correlated with EC, TSS, Na, and Cr, etc., while it was negatively correlated with AHN, OM, Se, Zn, and Fe, etc. These characteristics in marmot habitats, including low levels of organic matter, alkaline hydrolyzed nitrogen, zinc, selenium, and bacterial alpha diversity, as well as high levels of electrical conductivity, total soluble salts, iron, and nickel, played a crucial role in the spread of plague. It was discovered that the unique characteristics of marmot-soils provided essential elements necessary for the survival of Yersinia pestis, including high levels of Fe and Ca, or facilitated the spread of plague. Thus, the transmission of the plague was facilitated.

The Level of Serum Selenium in Patients with Cervical Intraepithelial Neoplasia in Medical City/ Baghdad Teaching Hospital

Introduction: Selenium is an essential trace element involved in different physiological functions of the human body. An inverse relationship between serum selenium levels and cervical intraepithelial neoplasia has been reported. cervical intraepithelial neoplasia is regarded as a potentially premalignant transformation of squamous cells of the cervix. Objectives: To evaluate the relationship between the serum level of selenium and cervical intraepithelial neoplasia. Methods: A case-control study was conducted at Baghdad Teaching Hospital and Iraqi National Cancer Research Center in the University of Baghdad during the period from July 2021 to July 2022. A convenient sample of 100 women was enrolled in the current study and included case group which consisted of 50 women who were diagnosed with cervical intraepithelial neoplasia and control group which consisted of 50 women who did not have cervical intraepithelial neoplasia as confirmed through histological examination after punch biopsy by colposcopy. Results: The serum level of the selenium was significantly lower in the case groups compared to the control groups (P-value=0.001). In addition, the proportion of the participant with abnormal levels of selenium was significantly higher in the case group compared to the control group (P-value=0.001). In the case group, there was a significant difference between the cervical intraepithelial neoplasia grade regarding the serum level of selenium, the level of selenium significantly decreased with the progression of the disease (P-value=0.001). Conclusions: Selenium deficiency may significantly increase the incidence of cervical intraepithelial neoplasia. In addition, it significantly impacts the transformation to a higher degree as there was a significant difference between cervical intraepithelial neoplasia I, II, and III regarding the level of serum selenium.

The Relationships among the Urinary Iodine Concentration, Selenium Intake, and Thyroid Antibodies in Adults, Including the Interaction between Iodine and Selenium: National Health and Nutrition Examination Survey 2007-2012.

The objective of this study was to examine the urinary iodine concentration (UIC)-thyroid autoimmunity (TAI) association and UIC-selenium intake interaction in U.S. adults. We analyzed 2007-2012 National Health and Nutrition Examination Survey (NHANES) data on ≥20-year-old adults (n = 6612). Their food and supplemental selenium intake was measured. The associations of the UIC and selenium intake with thyroid peroxidase antibody (TPOAb) positivity, thyroglobulin antibody (TgAb) positivity, and TAI were assessed via weighted multivariable logistic regression. Interaction and subgroup analyses were conducted. Nonlinear relationships were explored and visualized via restricted cubic splines (RCSs). Compared with a UIC 100~200 μg/L, a UIC 500~800 μg/L was associated with a 57% increased TPOAb positivity risk (OR = 1.57 [CI = 1.07-2.30]; p = 0.022), a one-fold greater TgAb positivity risk (OR = 2.00 [CI = 1.10-3.65]; p = 0.025), and a 62% increased TAI risk (OR = 1.62 [CI = 1.07-2.45]; p = 0.024). Nonlinear relationships between the UIC and thyroid antibody positivity were observed. According to the univariate models, each 1 μg increase in selenium intake was associated with a 0.049 IU/mL decrease in the TPOAb levels (β [95% CI] = -0.049 [-0.092--0.005]; p = 0.028). In the low-selenium group, a UIC of 200~300 μg/L was a risk factor for TPOAb positivity (p = 0.046). At a moderate level of selenium intake, a UIC of 300~800 μg/L significantly increased the TPOAb positivity risk (all p < 0.05). At a high level of selenium intake, the UIC and TPOAb positivity risks were not significantly associated (all p > 0.05). A UIC of 500~800 μg/L is an independent TAI risk factor. The selenium intake modifies the UIC-thyroid antibody positivity relationship, with the association disappearing at high selenium levels.

Zinc, copper, and selenium levels in vitiligo: a systematic review and meta-analysis

Vitiligo is a dermatological disease characterized by loss of melanocytes, causing non-scaly white macules on the skin. Zinc, copper, and selenium are important micronutrients that play a role in the normal functioning of the body and have been found to potentially aid in vitiligo treatment, although the relationship between their serum levels and vitiligo is not yet fully understood. This is a systematic review aimed at assessing the levels of serum zinc, copper, and selenium and their association with vitiligo. This review was performed following the Preferred Reporting Items of the systematic Review and Meta-Analysis (PRISMA) checklist and Cochrane guidelines. A comprehensive literature search was conducted on PubMed, Google Scholar and 41 studies published between 1970 and 2022 including 3353 vitiligo cases and 10,638 controls were included in the meta-analysis conducted from August 2022 till September 2023. The quality of the studies was assessed using the National Heart Lung and Blood Institute Study Quality Assessment tool, and the risk of bias was represented using the RobVis tool. The statistical analysis was performed using Review Manager (RevMan) Version 5.4. This meta-analysis indicate a significant decline in serum zinc levels (Z = 4.97; P < 0.0001; SMD = − 0.86; 95% CI − 1.19 to − 0.52) in vitiligo group with high statistical heterogeneity (Tau2 = 0.74; Chi2 = 513.95, d.f. = 26 [P < 0.00001]; I2 = 95%). Similarly for serum copper levels there was decline (Z = 2.43; P < 0.0001; SMD = − 0.50; 95% confidence interval [CI] − 0.91 to − 0.10) in vitiligo group and high statistical heterogeneity (Tau2 = 0.92; Chi2 = 475.10, d.f. = 22 [P < 0.00001]; I2 = 95%). On the other hand, there was a increase of serum selenium levels in the vitiligo group (Z = 0.56; P < 0.0001; SMD = 0.23; 95% confidence interval [CI], 0.58 to 1.04) and the results reveals high statistical heterogeneity among studies (Tau2 = 1.93; Chi2 = 406.44, d.f. = 11 [P < 0.00001]; I2 = 97%) in vitiligo patients compared to healthy controls. Publication bias was not found for the studies analysed. This study analyses the association of serum micronutrient levels and vitiligo among patients and controls from published research along with sub-group analysis specific to Asian populations using a meta-analysis. Low serum levels of Zinc and copper and high selenium levels are associated with Vitiligo.

Effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues.

This study was conducted to evaluate the effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues. A total of 44 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness, and parity were assigned to one of the three treatments with 14 or 15 sows per treatment in a completely randomized design. The treatments were as follows: i) Control, corn-soybean meal-based diet with no addition of selenium premix; ii) ISOS(mixed inorganic selenium and organic selenium) 30, a basal diet supplemented with 0.15 ppm of inorganic Se and 0.15 ppm of organic Se; iii) ISOS50, a basal diet supplemented with 0.25 ppm of inorganic Se and 0.25 ppm of organic Se. At day 21 of lactation, supplementing a high level of mixed Se at 0.50 ppm resulted in higher piglet BW and weight gain than adding a low level of mixed Se at 0.30 ppm (p<0.05). Selenium concentration of colostrum in sows fed ISOS50 diet was significantly higher than those in sows fed ISOS30 diet (p<0.05). Selenium concentrations in the serum at days 90 and 110 of gestation and 24 hours postpartum were highest when sows were fed ISOS50 diet (p<0.05). Additionally, increasing levels of mixed Se led to an increase in piglet serum Se concentration at 24 hours postpartum (p<0.05). Before ingesting colostrum, piglets from sows fed a mixed selenium (Se) diet had significantly higher kidney Se concentrations compared to those from the control group, with the ISOS50 treatment showing the most significant difference (p<0.05). Supplementation of the gestation diet with 0.5 ppm of mixed Se may improve piglet growth performance, increase Se concentrations in milk, and enhance Se status in the serum of sows, as well as in the serum and tissues of their offspring.

6492 Novel compound heterozygous mutations in the SBP2 gene

Abstract Disclosure: H. Jeong: None. Mutations in the selenocysteine insertion sequence binding protein 2 gene (SECISBP2 also known as SBP2) result in a multisystemic disorder. A 4-year-old Korean girl presented with atypical thyroid function test result, characterized by normal TSH 2.13 μIU/mL, decreased T3 0.51 ng/mL, free T3(FT3) 1.71 (pg/mL), and elevated free thyroxine (FT4) 4.28 ng/dL. Additionally, she exhibited short stature below 2 standard deviations and delayed bone age. She has not yet begun speaking, and her waking ability commenced only recently. She conceived twins through natural pregnancy, but tragically, her twin sibling passed away in utero at 8 weeks of gestation.A targeted next-generation sequencing panel revealed compound heterozygous mutation in SBP2 gene (p.Arg120Ter/p.Arg672Ter) and in TPO gene (p.Glu413Gln).Her serum selenium level was relatively low,, easuring at 6.94 ng/dL. She underwent T3 supplementation and received a daily selenium supplement of 20mcg. Subsequently, her thyroid function tests normalized. Presentation: 6/2/2024

The effects of selenium administration on mean platelet volume, neutrophil-to-lymphocyte ratio, and red cell distribution width in critically ill older adults: A double-blinded randomized clinical trial

BackgroundLow serum Selenium (Se) levels in critical patients have been associated with poor clinical outcomes and higher mortality rates. The purpose of this study was to investigate the effect of Se administration on mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (N/L), and red cell distribution width (RDW) in older adults admitted to the intensive care unit (ICU). MethodThis study was a double-blinded randomized clinical trial. Critically ill patients were randomly divided into two groups of Se and placebo. The Se group (N=30) initially received 3000 mg of Se at once within 3 hours, followed by a dose of 1500 mg daily for 10 days as a one-hour infusion. The control group (N=30) received normal saline for 10 days. A venous blood sample was collected on the first and 10th day. Statistical analysis was performed using SPSS.26 statistical software. To analyze quantitative data in two groups, based on the estimated normality, an independent t-test was used. P value less than 0.05 was considered statistically significant. ResultsOn day 10, the MPV value in the Se group was significantly lower compared to the placebo group (9.32 ± 1.78 and 10.43 ± 2.06, respectively, p = 0.03). Within the Se group, contrary to the controls, the MPV value decreased significantly from day 1 to day 10 (p<0.001). Further, the RDW value in the Se group was significantly lower compared to the placebo group (13.77 ± 1.57 and 15.32 ± 2.42, respectively, p = 0.005). The N/L ratio remained similar between the two groups before and after the intervention. ConclusionOur findings suggest that Se can affect the MPV and RDW parameters in older adults hospitalized in the ICU. However, further studies with a larger population are necessary to support these findings. Clinical Relevancy StatementThe effects of selenium administration on hematological parameters in older adults admitted to the ICU are not well-established. There is limited direct evidence linking serum selenium levels to erythrocyte and hemoglobin stability in humans. The current clinical trial promotes the current literature and shows that selenium holds potential in management of the older ICU patients.

The effects of Selenium phytotoxicity on two wheat (Triticum aestivum) cultivars differing in Se tolerance and the role of antioxidant enzymes in the tolerance mechanism

Abstract Wheat seedlings were hydroponically grown in Hoagland solution containing various levels of Se. Tolerance response to Se toxicity was investigated by determining the level of thiobarbituric acid reactive substance (TBARS), proline and chlorophyll content, the growth parameters, and the activity of antioxidant enzymes. The toxic level of Se treatment significantly retarded the seedling growth. A substantial amount of proline accumulation was also observed in response to toxic Se concentration, but it was more pronounced in putative-sensitive cultivars. Chlorophyll content significantly decreased in Se-intoxicated seedlings and increased at the lowest Se dose in both cultivars. Severe and mild chlorosis was observed in putative-sensitive and tolerant cultivars at the highest Se level. Alterations in the activities of glutathione reductase (GR, 1.6.4.2), glutathione S transferase (GST, 2.5.1.18), guaiacol peroxidase (GPX, 1.11.1.7), catalase (CAT, 1.11.1.6), and ascorbate peroxidase (APX, 1.11.1.11) and superoxide dismutase (SOD, EC 1.15.1.1) were determined. TBAR level did not significantly increase in putative tolerant cultivars as an indicator of membrane lipid peroxidation. However, a significant increase was observed in putative-sensitive cultivars in response to higher selenium concentrations. In higher Se treatment groups, CAT and GST activities significantly increased in putative Se tolerant cultivars. However, excluding SOD, the activity of all the studied enzymes was increased considerably in putative-sensitive cultivars in a dose-dependent manner. Higher antioxidant enzyme activities and a substantial amount of proline accumulation did not significantly contribute to overcoming Se phytotoxicity in wheat seedlings grown in media supplemented with toxic selenium levels.

Circulating levels of micronutrients and the risk of benign paroxysmal positional vertigo: A Mendelian randomization study

BackgroundBenign paroxysmal positional vertigo (BPPV) is a typical vestibular disease characterized by recurrent episodes of vertigo. The role of micronutrients in BPPV pathogenesis has not been extensively studied, prompting this investigation into the relationship between circulating micronutrients and BPPV risk. This research aimed to explore the relationship between blood micronutrient levels and BPPV risk via Mendelian randomization (MR) analysis, a robust method for inferring causality from observational data. MethodsA total of 15 circulating micronutrients were assessed for their association with BPPV risk. MR analysis was conducted via the following methods: MR‒Egger, weighted median, simple model, inverse variance weighting (IVW), and weighted mode. Sensitivity analyses were performed to assess heterogeneity and pleiotropy. A multivariate MR analysis was also conducted, incorporating potential confounders such as trauma, chronic otitis media, hearing loss, peripheral atherosclerosis, ageing, and osteoporosis. ResultsMR analysis revealed an obvious association between selenium and BPPV risk (OR 1.074, 95 % CI 1.005 to 1.148; P = 0.035). Folate was negatively related (OR 0.694, 95 % CI 0.501 to 0.962, P = 0.028) but was excluded because of inconsistent OR values across methods. Sensitivity analysis supported the IVW results, and there was no evidence of significant heterogeneity among the selenium-related instrumental variables included in the study, nor was horizontal pleiotropy detected among the instrumental variables. Multivariate MR analysis confirmed that selenium was an independent risk factor for BPPV (OR 1.22, 95 % CI 1.059 to 1.406, P = 0.006), with no significant associations observed for other micronutrients or exposure factors. ConclusionThis study provides evidence that blood selenium levels are positively associated with the risk of BPPV, suggesting a potential role for selenium in the pathogenesis of this disorder. These findings are robust to various sensitivity analyses and support the use of MR analysis to identify novel risk factors for BPPV. The identification of selenium as an independent risk factor for BPPV has implications for the development of preventive strategies and targeted interventions. It is necessary to analyse the biological mechanisms of this association and determine the therapeutic value of limiting selenium intake for BPPV to provide support for the treatment of such patients.

The Relationship of Trace Element Levels with Obesity and Cardiovascular Health

Objective: One of the most important factors affecting cardiovascular health is obesity. Trace elements, which play a role in every stage of metabolism, are also related to our cardiovascular health. The aim of this study was to determine serum trace element levels in individuals and to examine the relationship between trace elements and cardiovascular risk. Methods: This cross-sectional study was conducted with individuals who applied to the outpatient clinic between 01.03.2022-31.04.2022. Sociodemographic characteristics, BMI, and Framingham risk score values were recorded. Serum iron, zinc, copper and selenium levels were analyzed in the laboratory. Results: A total of 180 individuals were included in the study. Of the individuals, 33.3% were overweight and 32.8% were obese. The mean Framingham Risk Score (FRS) was 9.31±7.99 (1-37). FRS values of normal weight individuals (7.84±3.05) were lower than the mean FRS values of overweight (8.80±3.39) and obese (13.39 ± 6.24) groups (p

Serum CD5L as potential biomarker of thyroid hormone status during pregnancy.

The thyroid hormone (TH) status is routinely assessed by thyrotropin (TSH) and thyroxine (T4). Both biomarkers are mainly regulated by TH receptor beta, whereas many peripheral organs employ the alpha receptor. Serum cluster of differentiation 5-like molecule (CD5L) is a liver-derived protein under control of both TH receptor isoforms. However, clinical data on its relation to TH status are sparse. An additional biomarker of TH status is needed in particular during pregnancy, where the routine biomarkers become dynamically disturbed. This study aimed to determine possible covariates regulating serum CD5L and to test its potential suitability as additional TH biomarker during pregnancy. A sandwich ELISA for serum CD5L was established using newly raised antibodies. Circadian effects and the impact of liver disease on serum CD5L concentrations were assessed. Serum samples from pregnant women with well-characterized TH and trace element status were analyzed, and CD5L concentrations were correlated with other indicators of TH status including TSH, fT4, fT3, copper, and selenium concentrations. The new quantitative assay for CD5L showed high accuracy. Serum CD5L was stable in dilution and refreezing experiments and did not show strong circadian variance or dependency on liver disease. In serum of pregnant women, CD5L correlated positively to fT3, but not to fT4 or TSH. Significant positive correlations of CD5L were observed with serum levels of the TH-responsive trace elements selenium and copper. The data support the potential suitability of serum CD5L as an additional marker of TH status, with potential value for pregnancy and thyroid disease.

Methods established for the detection of mineral levels in whole blood by the dried blood spot technique

Mineral are intimately related to human health and disease, and detection of mineral content in the body is of great significance for the diagnosis and prevention of diseases. In this study, we validated the method developed to detect magnesium (Mg), copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) levels in dried blood spots (DBS). In accordance with the requirements of the guidelines for the Bioanalytical Method Validation Guidance for Industry, we evaluate the linearity, sensitivity, precision, accuracy and selectivity of the developed methods. In addition, Mg, Cu, Fe, Zn and Se were quantified in 195 older adults using DBS technique, and its accuracy was assessed by comparing the results to those detected by inductively coupled plasma-mass spectrometry (ICP-MS). The method has excellent sensitivity and linear range to cover the concentration range of mineral elements in the general population with the required precision, accuracy and selectivity. The correlation coefficients of Mg, Cu, Fe, Zn and Se levels in blood detected by the DBS technique and ICP-MS were 0.638, 0.823, 0.463, 0.728 and 0.751, respectively (all P < 0.05), which indicated that there was a strong correlation between the detection results of the two methods. More than 95 % of the sample results in the Bland-Altman consistency test were within the acceptable limits of agreement (LOA) range, indicating that they had good consistency. DBS technique has good accuracy and reliability in detecting blood mineral levels in the elderly, suggesting potential in the quantification of mineral level in blood.