The Correlation between Dietary Selenium Intake and Type 2 Diabetes: A Cross-Sectional Population-Based Study on North Chinese Adults

Selenium Species in Diabetes Mellitus Type 2

Selenium is an important trace element for humans and animals as it plays a key role in several major metabolic pathways. Several studies were conducted to better understand the role of selenium against diabetes mellitus (DM), particularly type 2 (T2DM), but the obtained conclusions are contradictory. A simple linear relationship does not exist between the risk of T2DM and selenium levels but is best represented in a dose-dependent manner, getting often the U-graph. This relation also depends on selenium chemical forms that are present in a diet or supplements. Both too low and too high selenium intakes could increase the risk of diabetes. Moreover, the baseline status of Se should be taken into consideration to avoid over-supplementation. The focus of this brief overview is to report the recent updates concerning selenium participation in diabetes mellitus.

Associations of metals and metal mixtures with glucose homeostasis: A combined bibliometric and epidemiological study

This study employs a combination of bibliometric and epidemiological methodologies to investigate the relationship between metal exposure and glucose homeostasis. The bibliometric analysis quantitatively assessed this field, focusing on study design, predominant metals, analytical techniques, and citation trends. Furthermore, we analyzed cross-sectional data from Beijing, examining the associations between 14 blood metals and 6 glucose homeostasis markers using generalized linear models (GLM). Key metals were identified using LASSO-PIPs criteria, and Bayesian kernel machine regression (BKMR) was applied to assess metal mixtures, introducing an "Overall Positive/Negative Effect" concept for deeper analysis. Our findings reveal an increasing research interest, particularly in selenium, zinc, cadmium, lead, and manganese. Urine (27.6%), serum (19.0%), and whole blood (19.0%) were the primary sample types, with cross-sectional studies (49.5%) as the dominant design. Epidemiologically, significant associations were found between 9 metals-cobalt, copper, lithium, manganese, nickel, lead, selenium, vanadium, zinc-and glucose homeostasis. Notably, positive-metal mixtures exhibited a significant overall positive effect on insulin levels, and notable interactions involving nickel were identified. These finding not only map the knowledge landscape of research in this domain but also introduces a novel perspective on the analysis strategies for metal mixtures.

Impact of age, sex, and thyroid autoimmunity on the association between selenium intake and type 2 diabetes mellitus

BACKGROUND

The association between dietary selenium(Se) intake and type 2 diabetes mellitus (T2DM) remains controversial. The present study aimed to investigate this association using data from the National Health and Nutrition Examination Survey (NHANES) database for the years 2007-2012.

METHODS

Three thousand seventy three individuals aged 20 years and above were eligible for inclusion in this cross-sectional study. The average age of the participants was 50.74 years and the proportions of males and females were nearly equal (49.12% vs. 50.88%). The odds ratios (OR) of the association between dietary Se intake (log2-transformed) and T2DM were examined through the multivariate logistic regression model. Subgroup analyses were conducted based on age, sex, and thyroid autoimmunity to assess the potential impact of these variables on the relationship. Fitted smoothing curves and threshold effect analysis were conducted to describe the nonlinear relationship.

RESULTS

In the fully adjusted model, a significant positive association between Se intake and T2DM was observed (OR = 1.49, 95% CI: 1.16, 1.90, p = 0.0017). After stratifying the data by age, sex, and thyroid autoimmunity, a significant positive association between Se intake and T2DM was observed in individuals under 65 years of age, males, and those with negative thyroid autoimmunity. A two-segment linear regression model was analyzed for sex stratification, revealing a threshold effect in males with an inflection point of 90.51 μg, and an inverted U-shaped relationship in females with an inflection point of 109.90 μg, respectively.

CONCLUSIONS

The present study found a positive relationship between Se intake and the prevalence of T2DM. This association is particularly significant in younger individuals, males, and those with negative thyroid autoimmunity. Our results should be validated in future large prospective studies in different populations.

Gut microbiota contribution to selenium deficiency-induced gut-liver inflammation

There is limited knowledge about the factors that drive gut-liver axis changes after selenium (Se) deficiency-induced gut or liver injuries. Thus, we tested Se deficiency in mice to determine its effects on intestinal bacterial balance and whether it induced liver injury. Serum Se concentration, lipopolysaccharide (LPS) level, and liver injury biomarkers were tested using a biochemical method, while pathological changes in the liver and jejunum were observed via hematoxylin and eosin stain, and a fluorescence spectrophotometer was used to evaluate intestinal permeability. Tight junction (TJ)-related and toll-like receptor (TLR) signaling-related pathway genes and proteins were tested using quantitative polymerase chain reaction, western blotting, immunohistochemistry, and 16S ribosomal ribonucleic acid gene-targeted sequencing of jejunum microorganisms. Se deficiency significantly decreased glutathione peroxidase activity and disrupted the intestinal flora, with the most significant effect being a decrease in Lactobacillus reuteri. The expression of TJ-related genes and proteins decreased significantly with increased treatment time, whereas supplementation with Se, fecal microbiota transplantation, or L. reuteri reversed these decreases. Signs of liver injury and LPS content were significantly increased after intestinal flora imbalance or jejunum injury, and the levels of TLR signaling-related genes were significantly increased. The results indicated that Se deficiency disrupted the microbiota balance, decreased the expression of intestinal TJ factors, and increased intestinal permeability. By contrast, LPS increased due to a bacterial imbalance, which may induce inflammatory liver injury via the TLR4 signaling pathway.

The Potential Effects of Dietary Antioxidants in Obesity: A Comprehensive Review of the Literature

Obesity has become a global health concern, with its prevalence steadily increasing in recent decades. It is associated with numerous health complications, including cardiovascular diseases, diabetes, and certain types of cancer. The aetiology of obesity is multifactorial, involving genetic, environmental, and lifestyle factors. In recent years, oxidative stress has emerged as a potential contributor to obesity and its related metabolic disorders. Dietary antioxidants, which can counteract oxidative stress, have gained significant attention for their potential role in preventing and managing obesity. This comprehensive review aims to explore the impact of dietary antioxidants on obesity and its associated metabolic dysregulations, discussing the underlying mechanisms and highlighting the potential therapeutic implications.

Dietary Antioxidant Quality Score (DAQS), serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among apparently metabolically healthy obese adults in two metropolises of Iran (Tabriz and Tehran): a cross-sectional study

BACKGROUND

Oxidative stress (OS) is associated with a variety of non-communicable diseases, including MetS, diabetes mellitus, metabolic syndrome, and cardiovascular disease through increased production of reactive oxygen species (ROS) and impairment of antioxidant defense mechanisms. Antioxidants can protect cells against free radical damage, so it seems important to determine the relationship between the quality of dietary antioxidants intake and chronic diseases. The Dietary Antioxidant Quality Score (DAQS) is obtained by adding the daily intake of known dietary vitamins and minerals, including selenium, zinc, vitamin A, vitamin C, and vitamin E, compared to the recommended daily intake (RDI). Therefore, this study aims to determine the relationship between DAQS, serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among obese adults.

METHODS

In the present cross-sectional study, 338 individuals who were obese (BMI ≥ 30 kg/m²) aged 20-50 years were recruited from Tabriz and Tehran, Iran. A validated semi-quantitative Food Frequency Questionnaire (FFQ) with 168 food items was used to quantify dietary consumption; accordingly, DAQS was computed. Blood biomarkers were measured using enzyme-linked immunosorbent assay (ELISA) kits. A standard mercury sphygmomanometer was used to assess blood pressure, and bioelectrical impedance analysis (BIA) was performed to determine body composition. The association between the DAQS tertiles and biochemical variables was investigated using multinomial logistic regression.

RESULTS

Participants in the highest tertile of DAQS have a lower diastolic blood pressure (DBP) values in all of the adjusted models [odds ratio (OR) = 0.920; confidence interval (CI)= 0.852-0.993, P-value = 0.03] in the analysis of co-variance (ANCOVA) model. Similarly, subjects at the second tertile of DAQS had lower DBP compared with the first tertile in age and sex-adjusted model [OR= 0.937; CI= 0.882-0.997]. There was no statistically significant difference for other metabolic parameters in different DAQS tertiles.

CONCLUSION

According to our findings, higher DAQS was associated with lower DBP among obese adults with obesity in two major cities of Iran (Tehran and Tabriz). Other studies with interventional design are needed to better elucidate these associations and underlying mechanisms.

Association of Selenium Intake and Selenium Concentrations with Risk of Type 2 Diabetes in Adults: A Narrative Review

Several recent studies have suggested selenium (Se) as a potential risk factor for diabetes mellitus (DM); however, the relationship between high Se levels and type 2 diabetes mellitus (T2DM) risk remains unclear. This review article aimed to provide a comprehensive discussion to clarify the association between high dietary Se intake and blood Se concentrations and the risk of T2DM among adults. We conducted searches in the PubMed, Science Direct, and Google Scholar databases for the years 2016 to 2022 and evaluated 12 articles from systematic reviews, meta-analyses, cohort studies, and cross-sectional studies. This review found a controversial association between high blood Se concentrations and T2DM risk while demonstrating a positive correlation with DM risk. In contrast, there are conflicting results regarding the association between high dietary Se intake and T2DM risk. Thus, longitudinal studies and randomized controlled trials are needed to better elucidate the link.

Associations of dietary antioxidant micronutrients with the prevalence of obesity in adults

Background

Antioxidant micronutrients have a therapeutic potential for clinical treatment of obesity. NO research, however, has examined the connection between the complex level of dietary antioxidants and obesity.

Materials and methods

We mainly aimed to investigate the relationship between a combination of antioxidants and obesity using the database of the national health and nutrition examination survey (NHANES). This cross-sectional study contains a survey of 41,021 people (≥18 years) in total ranging from 2005 to 2018. Multivariate logistic and weighted quantile sum (WQS) regression were performed to investigate the associations between these antioxidants, both individually and collectively, and the prevalence of obesity. The restricted cubic spline (RCS) regression was also utilized to analyze the linearity of these associations.

Results

According to multivariate logistic models, we found that the levels of most antioxidants in the highest quartile were independently related to a lower prevalence of obesity, while a reverse result was observed in selenium (p for trend <0.05). The WQS index revealed that a total of the 11 antioxidants is negatively related to the prevalence of obesity and abdominal obesity (all p<0.001), and iron/vitamin C have the greatest weight in the negative associations between antioxidant complex and obesity, as well as abdominal obesity. In addition, the RCS regression showed that retinol, vitamin A, α-carotene, β-carotene, β-cryptoxanthin, vitamin C, iron, and copper all had a non-linear association with obesity. Threshold effect analysis demonstrated that the inflection points of retinol, vitamin A, α-carotene, β-carotene, β-cryptoxanthin, vitamin C, iron, and cooper were 235.57, 374.81, 58.89, 891.44, 30.70, 43,410.00, 11,240.00, and 990.00 μg/day, respectively.

Conclusion

Our study found that a high level of a complex of 11 dietary antioxidants is related to a lower prevalence of obesity and abdominal obesity, among this inverse associations iron and vitamin C have the greatest weight.

Dietary selenium intake in relation to non-alcoholic fatty liver disease assessed by fatty liver index and hepatic steatosis index; a cross-sectional study on the baseline data of prospective PERSIAN Kavar cohort study

BACKGROUND

There is limited and conflicting evidence on the association between selenium and non-alcoholic fatty liver disease (NAFLD). Therefore, the present population-based cross-sectional study aimed to explore the relationship between dietary selenium intake and the risk of NAFLD.

METHODS

A total of 3026 subjects from the PERSIAN (Prospective Epidemiological Research Studies in IrAN) Kavar cohort study were included in the analysis. The daily selenium intake was evaluated using a semi-quantitative food frequency questionnaire, and energy-adjusted quintiles of selenium intake (µg/day) were calculated. NAFLD was defined as the fatty liver index (FLI) ≥ 60 or the hepatic steatosis index (HSI) > 36. The association between dietary selenium intake and NAFLD was evaluated using logistic regression analysis.

RESULTS

The prevalence rates of NAFLD were 56.4% and 51.9%, based on the FLI and HSI markers, respectively. The odds ratios (ORs) for FLI-defined NAFLD were 1.31 (95% confidence interval (CI): 1.01-1.70) and 1.50 (95% CI: 1.13-1.99) for the fourth and fifth quintiles of selenium intake, respectively, after adjustment for sociodemographic variables, smoking status, alcohol drinking, physical activity, and dietary factors (P trend = 0.002). There was also a similar association between selenium intakes and HSI-defined NAFLD (OR = 1.34 (95% CI: 1.03-1.75) for the fourth quintile and OR = 1.50 (95% CI: 1.12-2.01) for the fifth quintile of selenium intake) (P trend = 0.006).

CONCLUSION

In this large sample study, we observed a weak positive association between dietary selenium intake and NAFLD risk.

Association of Serum Antioxidant Minerals and Type 2 Diabetes Mellitus in Chinese Urban Residents

Antioxidant minerals including zinc, copper and selenium play critical roles in the maintenance of the redox balance in the body. However, their influences on type 2 diabetes mellitus (T2DM) are still inconclusive in Chinese populations. To elucidate the relationship between antioxidant minerals and T2DM, serum zinc, copper and selenium concentrations were measured in 1443 Chinese urban residents using a 1:2 matched case-control study. Conditional logistic regression models (CLR) were used to obtain the odds ratios (ORs) and 95% confidence intervals (CIs), and restricted cubic splines (RCS) were used to examine their dose−response associations. Serum zinc (OR = 0.52 [0.35, 0.77]) and copper concentrations (OR = 0.25 [0.17, 0.37]) were negatively associated with T2DM in a fully adjusted model. An L-shaped zinc-T2DM association (Poverall association = 0.003, and Pnonlinearity = 0.005) and a negative linear copper-T2DM association (Poverall association < 0.0001, and Pnonlinearity = 0.395) were observed. No association was found between serum selenium and T2DM in fully adjusted CLR or RCS models. In addition, joint associations with T2DM were identified between serum zinc and copper and between serum selenium and copper. In conclusion, our study emphasizes the importance of an adequate intake of antioxidant minerals for T2DM prevention in the Chinese population.

Relationship between dietary selenium intake and serum thyroid function measures in U.S. adults: Data from NHANES 2007-2012

Although numerous studies have explored the relationship between selenium intake and thyroid diseases, few epidemiological studies have investigated the association between selenium intake and thyroid hormones. Therefore, we conducted this analysis to investigate the association between dietary selenium intake and thyroid hormones. Our sample included 5,575 adults (age ≥ 20) years from the National Health and Nutrition Examination Survey (NHANES) 2007-2012. Thyroid hormones, including total triiodothyronine (T3), total thyroxine (T4), free T3 (FT3), free T4 (FT4), and thyroid-stimulating hormone (TSH), were detected. Multivariable linear regression models showed that log10-transformed selenium intake (LogSe) was negatively correlated with TT4 (β = -0.383, 95% CI: -0.695, -0.070) and TT4/TT3 (β = -0.003, 95% CI: -0.006, -0.0004) in U.S. adults. Besides, additional stratified analyses by sex demonstrated that LogSe was negatively associated with TT4 (β = -0.007, 95% CI: -0.013, -0.001) and TT4/TT3 (β = -0.664, 95% CI: -1.182, -0.146) and positively associated with FT4/TT4 (β = 0.031, 95% CI: 0.004, 0.059) in male adults. Meanwhile, subgroup analysis by iodine status showed that LogSe was negatively associated with TT4 (β = -0.006, 95% CI: -0.011, -0.002), FT4/FT3 (β = -0.011, 95% CI: -0.023, -0.00002) and TT4/TT3 (β = -0.456, 95% CI: -0.886, -0.026) in iodine sufficiency but not in iodine deficiency adults. Our results demonstrated that the increased dietary selenium intake was negatively correlated with TT4 and TT4/TT3 in U.S. adults. Furthermore, the association between dietary selenium intake and thyroid hormones was more pronounced in males and iodine sufficiency adults.

Sex-Specific Association between Fasting Plasma Glucose and Serum Selenium Levels in Adults from Southern Mexico

Selenium (Se) is an essential trace element that by its antioxidant properties has been studied to elucidate its participation in the development of obesity and type 2 diabetes. We evaluated the association between cardiometabolic traits and serum Se levels in a sample of adults from southern Mexico. In 96 nondiabetic individuals, anthropometric data and clinical biochemistry measurements were analyzed. Serum total Se levels were measured with inductively coupled plasma mass spectrometry (ICP-MS). Serum Se level in the whole sample was 10.309 ± 3.031 μg mL⁻¹ and no difference between the women and men was observed (p = 0.09). Additionally, fasting plasma glucose (FPG) was significantly associated with serum Se level (β = −0.07 ± 0.03, p = 0.02, analysis adjusted for age, sex and BMI). Furthermore, sex shows significant interaction with FPG on the serum Se levels (p = 0.01). A follow-up analysis revealed the particular association between FPG and Se levels in women (β = −0.10 ± 0.04, p = 0.01). In conclusion, our data evidenced a women-specific association between FPG and serum Se levels in a sample of adults from southern Mexico.

Associations between whole blood trace elements concentrations and HbA1c levels in patients with type 2 diabetes

Previous researches have been conducted to study the associations of trace elements on Type 2 diabetes (T2D) risk. The present study focuses on the evaluation of potential associations between trace elements and Hemoglobin A1c (HbA1c) in patients with T2D, via the determination of their levels in human whole blood. 100 diabetes without complications, 75 prediabetes and 40 apparently healthy subjects were studied. The levels of eleven trace elements including lithium (Li), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), selenium (Se), strontium (Sr) and molybdenum (Mo) were measured using inductively coupled plasma mass spectrometry (ICP-MS). The levels of fasting glucose, HbA1c, Hemoglobin, lipid, liver function, kidney function, thyroid function and demographic data were obtained from the Laboratory Information System. Nonparametric correlation (Spearman) was used to analyze the relationship between trace elements and HbA1c. The contents of V, Cr, Mn, Fe, Co, Cu, Zn and Mo in diabetes increased comparing with the healthy subject while Li decreased. But the levels of Li, V, Cr, Mn, Co, Se and Mo negatively correlated with HbA1c in the diabetes subjects (r value: - 0.2189, - 0.2421, - 0.3260, - 0.2744, - 0.2812, - 0.2456, - 0.2240; 95% confidence interval - 0.4032 to - 0.0176, - 0.4235 to - 0.0420, - 0.4955 to - 0.1326, - 0.4515 to - 0.0765, - 0.4573 to - 0.0838, - 0.4266 to - 0.0458, - 0.4076 to - 0.0229; p < 0.05, p < 0.05, p < 0.001, p < 0.01, p < 0.01, p < 0.05, p < 0.05). Accordingly, the contents of V, Cr, Mn and Se showed lower in HbA1c ≥ 7.0% group in contrast to HbA1c < 7.0% group. No correlation of HbA1c (or FBG) and trace elements was found in the healthy subjects. Trace element levels and metabolic abnormalities of blood glucose may be mutually affected. The extra supplement of trace elements needs to be cautious.

The relationship between dietary selenium intake and telomere length among diabetes

Se is an indispensable trace element for the human body, and telomere length is considered a marker of biological ageing. Previous studies have shown that dietary Se intake is associated with telomere length. However, the relationship between Se intake and telomere length in patients with diabetes has not been well studied. Therefore, this study aimed to investigate the relationship between dietary Se intake and telomere length in patients with diabetes. We extracted 878 participants with diabetes from the National Health and Nutrition Examination Survey database for 1990-2002. Dietary Se intake was assessed using the 24 h dietary recall method, and telomere length was measured using quantitative PCR. Generalised linear models were constructed to assess the relationship between dietary Se intake and telomere length. After controlling for the confounders, 1 μg increase in dietary Se intake in female patients with diabetes, and telomere length increased by 1·84 base pairs (β = 1·84 (95 % CI: 0·15, 3·53)), there was a line relationship between dietary Se intake and telomere length in female patients with diabetes and telomere length increased with increasing dietary Se intake within the range of 0-250 μg. The study demonstrates that dietary Se intake is significantly associated with telomere length only in the female population with diabetes in the USA. However, further prospective studies are required to confirm this finding.

Dietary Copper and Selenium Intakes and the Risk of Type 2 Diabetes Mellitus: Findings from the China Health and Nutrition Survey

The long-term associations between dietary copper (Cu) and selenium (Se) intakes and type 2 diabetes mellitus (T2DM) risk are unclear. We aimed to examine the prospective associations between dietary Cu and Se intakes and T2DM risk in Chinese adults. A total of 14,711 adults from the China Health and Nutrition Survey (1997–2015) were included. Nutrient intakes were assessed by 3 consecutive 24 h recalls and food-weighing methods. T2DM was identified by a validated questionnaire and laboratory examination. Cox regression models were used for statistical analysis. A total of 1040 T2DM cases were diagnosed during 147,142 person-years of follow-up. In fully adjusted models, dietary Cu or Se intake was not associated with T2DM risk. Dietary Se intake significantly modified the association between dietary Cu intake and T2DM risk, and dietary Cu intake was positively associated with T2DM risk when Se intake was lower than the median (p-interaction = 0.0292). There were no significant effect modifications on the associations by age, sex, BMI, or region. Although dietary Cu or Se intake was not independently associated with T2DM risk in Chinese adults free from cardiometabolic diseases and cancer at the baseline, there was a significant interaction between dietary Cu and Se intakes on T2DM risk.

The Role of Selenium in Pathologies: An Updated Review

Selenium is an essential microelement required for a number of biological functions. Selenium—and more specifically the amino acid selenocysteine—is present in at least 25 human selenoproteins involved in a wide variety of essential biological functions, ranging from the regulation of reactive oxygen species (ROS) concentration to the biosynthesis of hormones. These processes also play a central role in preventing and modulating the clinical outcome of several diseases, including cancer, diabetes, Alzheimer’s disease, mental disorders, cardiovascular disorders, fertility impairments, inflammation, and infections (including SARS-CoV-2). Over the past years, a number of studies focusing on the relationship between selenium and such pathologies have been reported. Generally, an adequate selenium nutritional state—and in some cases selenium supplementation—have been related to improved prognostic outcome and reduced risk of developing several diseases. On the other hand, supra-nutritional levels might have adverse effects. The results of recent studies focusing on these topics are summarized and discussed in this review, with particular emphasis on advances achieved in the last decade.

The Impact of Selenium Supplementation on Trauma Patients-Systematic Review and Meta-Analysis

This study aimed to assess current evidence regarding the effect of selenium (Se) supplementation on the prognosis in patients sustaining trauma. MEDLINE, Embase, and Web of Science databases were searched with the following terms: “trace element”, “selenium”, “copper”, “zinc”, “injury”, and “trauma”. Seven studies were included in the meta-analysis. The pooled results showed that Se supplementation was associated with a lower mortality rate (OR 0.733, 95% CI: 0.586, 0.918, p = 0.007; heterogeneity, I² = 0%). Regarding the incidence of infectious complications, there was no statistically significant benefit after analyzing the four studies (OR 0.942, 95% CI: 0.695, 1.277, p = 0.702; heterogeneity, I² = 14.343%). The patients with Se supplementation had a reduced ICU length of stay (standard difference in means (SMD): −0.324, 95% CI: −0.382, −0.265, p < 0.001; heterogeneity, I² = 0%) and lesser hospital length of stay (SMD: −0.243, 95% CI: −0.474, −0.012, p < 0.001; heterogeneity, I² = 45.496%). Se supplementation after trauma confers positive effects in decreasing the mortality and length of ICU and hospital stay.

Associations of Habitual Mineral Intake with New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Associations between habitual dietary intake of minerals and glucose metabolism have been extensively studied in relation to metabolic disorders. However, similar research has yet to be conducted in individuals after acute pancreatitis (AP). The main aim was to investigate the associations between habitual intake of 13 minerals and glycaemic status: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Associations between the dietary intake of minerals and markers of glucose metabolism (glycated haemoglobin and fasting plasma glucose) were also studied. The EPIC-Norfolk food frequency questionnaire was used in a cross-sectional fashion to determine the habitual intake of 13 dietary minerals. ANCOVA as well as multiple linear regression analyses were conducted and five statistical models were built to adjust for covariates. The study included 106 individuals after AP. In the NODAP group, intake of 4 minerals was significantly less when compared with the NAP group: iron (B = -0.076, p = 0.013), nitrogen (B = -0.066, p = 0.003), phosphorous (B = -0.046, p = 0.006), and zinc (B = -0.078, p = 0.001). Glycated haemoglobin was significantly associated with iodine intake (B = 17.763, p = 0.032) and manganese intake (B = -17.147, p = 0.003) in the NODAP group. Fasting plasma glucose was significantly associated with manganese intake (B = -2.436, p = 0.027) in the NODAP group. Habitual intake of minerals differs between individuals with NODAP, T2DM, and NAP. Prospective longitudinal studies and randomised controlled trials are now warranted to further investigate the associations between mineral intake and NODAP.

High-Accuracy Determination of Potassium and Selenium in Human Serum by Two-Step Isotope Dilution ICPMS

A high-accuracy measurement technique for determining potassium and selenium in human serum was developed by using two-step Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry (ICPMS) in this research. A more accessible method of the quadrupole ICPMS was employed in this research to achieve an equally high accuracy which had been achieved by a much more expensive method, namely, high-resolution sector field ICPMS (SF-ICPMS), with a comparatively easy and simple operation. In addition, we have evaluated the uncertainty of this method. The results showed that the determination limits of potassium and selenium in serum were 0.8 mg/kg and 2.7 μg/kg, respectively, and the precision for both measurements was lower than 0.2% and 0.7%. The measurement, when employed to measure potassium and selenium in standard materials NIST956D, NIST909C, and GBW09152, had caused a maximum deviation of less than 0.9%, within the stated uncertainty range of standard materials. The RELA international inter-laboratory comparisons of potassium in serum in 2018 conducted by our laboratory also yielded a satisfactory result.

Selenium Intake and Glycemic Control in Young Adults With Normal-Weight Obesity Syndrome

Numerous endogenous functions related to antioxidant processes, reproduction, and thyroid metabolism, as well as actions related to glycemic control, have been attributed to selenium. This study aimed to evaluate whether dietary selenium consumption is associated with variables of glycemic control in a sample of young Brazilian adults with Normal-Weight Obesity (NWO) syndrome. This was a cross-sectional study that evaluated 270 individuals with adequate body weight and excess body fat, who had their body composition assessed by dual-energy X-ray absorptiometry. Socioeconomic, health, and lifestyle questionnaires and three 24-h food records were applied. Glycemic control markers were also evaluated. The prevalence of inadequate selenium intake was analyzed by the Estimated Average Requirement (EAR) cut-point method. The prevalence of disturbances in glycemic control markers according to selenium consumption was compared by either the chi-square or the Fisher's exact test, with individuals classified according to the EAR values for selenium. The associations were evaluated by multiple linear regressions, using the backward strategy. The mean ± standard deviation (SD) age was 23.7 ± 3.3 years, and the mean ± SD daily selenium intake was 59.2 ± 26.4 μg. The overall prevalence of inadequate selenium intake was 59.2%. Individuals with selenium intakes below the EAR (≤45 μg/day) showed higher concentrations of glycated hemoglobin (HbA_1c) (P = 0.002) and a higher prevalence of disturbances in HbA_1c than those with selenium intakes above the EAR (>45 μg/day) (P = 0.001). Dietary selenium intake was directly associated with female sex (β = 19.95, 95% CI 5.00 to 34.89; P = 0.001) and weight (β = 6.69, 95% CI 0.56 to 12.81; P = 0.010), and inversely associated with the percentage of total body fat (β = -0.80, 95% CI -1.56 to -0,04; P = 0.010) and HbA_1c (β = -7.41, 95% CI -13.06 to -1.75; P = 0.010). Considering the noticeable young age of the individuals evaluated and the high frequency of disturbances in HbA_1c concentrations in those with selenium consumption below the recommendation, it is suggested that adequate dietary intake or supplementation of this micronutrient should be guaranteed to prevent future possible complications associated with glycemic control disturbances.

Dietary copper and selenium are associated with insulin resistance in overweight and obese Malaysian adults

Imbalance in or inadequate intake of micronutrients may impair insulin synthesis, secretion, and its signaling pathways. This study aimed to investigate the associations between dietary copper (Cu) and selenium (Se) with insulin resistance (IR), in overweight/obese adults. We hypothesized that dietary Cu and Se are non-linearly associated with IR. A cross-sectional study was conducted in 128 non-diabetic overweight and obese Malaysian adults aged ≥18 years with a body mass index ≥23kg/m². Dietary intake was assessed using food frequency questionnaire. IR was defined using a homeostatic model assessment-insulin resistance (HOMA-IR) threshold of ≥1.7. Locally weighted scatterplot smoothing (LOESS) regression was performed to detect non-linearity and piecewise regression models were computed to examine the trend of associations at different cut off points. In this study, 45% (n = 57) of the study participants were found to be insulin resistant. A U-shaped non-linear relation between Se and HOMA-IR was observed. Three-piecewise regression models revealed positive association between Se and HOMA-IR in individuals with relatively low (<0.3 µg/kg/day) and high (≥1.01 µg/kg/day) intake of Se (β-coefficient= 3.835, CI = -12.216-19.886, P = .614; and β-coefficient = 0.785, CI = 0.386-1.185, P = .014, respectively). Significant positive association was only found between dietary Cu and HOMA-IR with intake of Cu ≥13.4 µg/kg/day, 0.276 (CI = 0.025-0.526; P = .033). In conclusion, our findings reveal that a critical balance in the dietary intake of copper and selenium is crucial for health, much more in insulin resistant and diabetic individuals. In the latter, treatment should include measured intake of both copper and selenium, personalized according to individual habitual food preferences and intakes.

Dietary selenium intake and risk of hospitalization for type 2 diabetes in the Moli-sani study cohort

BACKGROUND AND AIMS

Experimental and non-experimental human studies have consistently shown a positive association between exposure to the trace element selenium, which occurs primarily through diet, and risk of type 2 diabetes mellitus. Plausible biological mechanisms include adverse effects of selenium and selenium-containing proteins on glucose metabolism. However, the levels of exposure above which risk increases are uncertain.

METHODS AND RESULTS

We examined the association between selenium intake and first hospitalization for type 2 diabetes during a median follow-up period of 8.2 years among 21,335 diabetes-free participants in the Moli-sani cohort, Italy. Selenium intake was ascertained at baseline using a food frequency questionnaire, showing a median value of 59 μg/day. During follow-up, we identified 135 incident cases of hospitalization for diabetes, based on population-based hospital discharge data. We used a Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for hospitalization for diabetes, adjusting for potential confounders. HRs (95% CIs) were 1.01 (0.60-1.70), 1.13 (0.66-1.96) and 1.75 (0.99-3.10) comparing the second, third, and fourth sex-specific quartiles with the first quartile, respectively. Risk was 64% greater in the fourth quartile as compared with the previous three. Spline regression analysis also indicated a steeper increase in risk occurring among men compared with women.

CONCLUSIONS

In a large population of Italian adults free of type 2 diabetes at cohort entry, high dietary selenium intake was associated with increased risk of hospitalization for diabetes.

Dietary Selenium Intake and Type-2 Diabetes: A Cross-Sectional Population-Based Study on CUME Project

Background and Aim: Previous studies have suggested that the specific association between selenium (Se) and diabetes remains unclear. This study aimed to investigate the association between dietary Se and type-2 diabetes (T2D) in the Brazilian cohort [Cohort of Universities of Minas Gerais (CUME)]. Methods and Results: This cross-sectional study was conducted with a large sample comprising 4,106 participants of the CUME project, a concurrent open cohort restricted to a highly educated population group, composed of graduates of federal institutions of higher education located in the State of Minas Gerais, Brazil. Data on socioeconomic and dietary characteristics, as well as anthropometric measures, were collected from each subject for analysis. The sample was classified into energy-adjusted tertiles of dietary Se intake (μg/day). Differences in the continuous data were evaluated by the Kruskal-Wallis H-test (abnormal data), and the χ²-test assessed differences in qualitative data. As there was no relationship between T2D and Se intake in the bivariate analysis, multivariate analysis was not performed. The prevalence of T2D in the studied population was 2.8%. The mean age was 36 years. Regarding gender, 1,209 are males and 2,807 are females. Among females, the mean Se intake was 165.12 μg/day and the mean intake was 157.4 μg/day. Among males, it was 168.4 μg/day. Significant differences were observed across all Se intake tertiles in terms of age, gender, activity level, alcohol intake, energy intake, sugar, carbohydrates, lipids, fiber, and energy-adjusted meat intake. However, no significant differences were observed across all Se intake tertiles in terms of BMI, smoking status, and T2D. The results indicated that there was no significant association between dietary Se intake and the prevalence of T2D. Conclusion: Dietary Se intake was not associated with the prevalence of T2D, despite the high intake of this micronutrient in the sample. These results contradict studies that identified the association between Se intake and T2D, with values of Se intake much lower than those observed in this study. Thus, this relationship seems to remain controversial.