Association of trace metal elements with lipid profiles in type 2 diabetes mellitus patients: a cross sectional study

Associations between individual and mixed urinary metal exposure and dyslipidemia among Chinese adults: Data from the China Multi-Ethnic Cohort Study

The prevalence of dyslipidemia is increasing, and it has become a significant global public health concern. Some studies have demonstrated contradictory relationships between urinary metals and dyslipidemia, and the combined effects of mixed urinary metal exposure on dyslipidemia remain ambiguous. In this study, we examined how individual and combined urinary metal exposure are associated with the occurrence of dyslipidemia. According to the data from the 2018-2019 baseline survey database of the China Multi-Ethnic Cohort (CMEC) Study, a population of 9348 individuals was studied. Inductively coupled plasmamass spectrometry (ICP-MS) was used to measure 21 urinary metal concentrations in the collected adult urinary samples. The associations between urinary metals and dyslipidemia were analyzed by logistic regression, weighted quantile sum regression (WQS), and quantile-based g-computation (qgcomp), controlled for potential confounders to examine single and combined effects. Dyslipidemia was detected in 3231 individuals, which represented approximately 34.6 % of the total population. According to the single-exposure model, Al and Na were inversely associated with the risk of dyslipidemia (OR = 0.95, 95 % CI: 0.93, 0.98; OR = 0.89, 95 % CI: 0.83, 0.95, respectively), whereas Zn, Ca, and P were positively associated (OR = 1.69, 95 % CI: 1.42, 2.01; OR = 1.12, 95 % CI: 1.06, 1.18; OR = 1.21, 95 % CI: 1.09, 1.34, respectively). Moreover, Zn and P were significantly positively associated even after adjusting for these metals, whereas Al and Cr were negatively associated with the risk of dyslipidemia. The results of the WQS and qgcomp analyses showed that urinary metal mixtures were positively associated with the risk of dyslipidemia (OR = 1.26, 95 % CI: 1.15, 1.38; OR = 1.09, 95 % CI: 1.01, 1.19). This positive association was primarily driven by Zn, P, and Ca. In the sensitivity analyses with collinearity diagnosis, interaction, and stratified analysis, the results remained, confirming the reliability of the study findings. In this study, the individual and combined effects of urinary Zn, P, and Ca on dyslipidemia were determined, which provided novel insights into the link between exposure to metals and dyslipidemia.

Plasma levels and dietary intake of minerals in patients with type 2 diabetes and chronic kidney disease: A case-control study

BACKGROUND AND AIM

Diabetic kidney disease (DKD) is the primary cause of chronic kidney disease (CKD) worldwide. Altered mineral levels leading to adverse outcomes are widely reported in diabetes but limited in DKD, in the Indian scenario, hence this study was taken up to address this issue.

METHODS

A hospital-based case-control study was taken up with 54 healthy controls (C) and 140 subjects with type 2 diabetes wherein 74 subjects with diabetes and CKD formed the DKD group, and 66 subjects with diabetes but no CKD formed the diabetic no-chronic kidney disease (DNCKD) group. High-resolution inductively coupled plasma mass spectrometry was used to evaluate the blood levels of minerals (calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), and selenium (Se)), and a raw food-based food frequency questionnaire for dietary intakes. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (mL/min/1.73 m2) and albuminuria. Spearman's rank correlation was used to evaluate the relationship between the categorical variables.

RESULTS

The median values of plasma Ca in the DKD group were significantly lower compared with the DNCKD and C groups (10.5 mg/dL vs. 11.0 mg/dL and 11.7 mg/dL, p<0.001). Furthermore, plasma Ca levels lowered with declining kidney function, as evidenced by the eGFR and albuminuria segregation. Dietary intake of minerals did not correlate with the corresponding plasma levels. However, in the DKD group, eGFR correlated positively with the plasma levels of Ca (r= 0.422, p=0.001), Cr (r= 0.351, p=0.008), Mn (r= 0.338, p=0.011), Fe (r= 0.403, p=0.002), Cu (r= 0.274, p=0.041) and negatively with Se (r= -0.486, p<0.001).

CONCLUSION

Plasma Ca levels are lower in the DKD group with a strong positive association with eGFR, indicating its role in predicting the onset and progression of kidney function decline.

"Green" synthesized versus chemically synthesized zinc oxide nanoparticles: In vivo antihyperglycemic activity and pharmacokinetics

Zinc is one of the most studied trace elements, commonly used as supplement in diabetes treatment. By its involvement in the synthesis, secretion of insulin, promotion of insulin sensitivity and its multiple enzymatic functions it is known to contribute to reduce hyperglycemia. Researchers have shown that zinc administered under the form of zinc oxide nanoparticles (ZnONPs) is more effective than under its ionic form. Studies evaluating the antihyperglycemic activity of these nanocarriers include both ZnONPs synthesised using plants (i.e. green synthesized) or chemically synthesized. The present work aims to compare green synthesized ZnONPs with the marketed chemically synthesized ones. Green ZnONPs were synthesized using the aqueous extract of the stem bark of the medicinal plant Panda oleosa and zinc nitrate hexahydrate. Both nanocarriers were compared in terms of optical properties, morphology, composition, chemical functions, resistance to oxidation, in vivo antihyperglycemic activity via oral glucose tolerance test (OGTT) and pharmacokinetics in relation to zinc in C57BL/6J mice. A UV absorption peak was observed at 354 nm and 374 nm for the green and marketed ZnONPs, respectively. The shape and hydrodynamic diameters were anisotropic and of 228.8 ± 3.0 nm for the green ZnONPs and spherical and of 225.6 ± 0.9 nm for the marketed ZnONPs. Phenolic compounds accounted for 2.58 ± 0.04% of the green ZnONPs and allowed them to be more stable and unaffected by an oxidizing agent during the experiment, while the marketed chemically synthesized ZnONPs aggregated with or without contact with an oxidizing agent. No significant differences were observed on the amounts of zinc absorbed when comparing green ZnONPs, chemically synthesized ZnONPs and zinc sulfate in a pharmacokinetics study in normoglycemic mice. When evaluating the in vivo hypoglycemic activity of the nanocarriers in obese/diabetic mice, green synthesized ZnONPs displayed a significant hypoglycemic effect compared with the chemically synthesized nanoparticles following an OGTT. Altogether, these data indicate that phytocompounds, as catechin derivatives and polyphenols, attached to the green synthesized ZnONPs' surface, could contribute to their hypoglycemic activity. The comparison thus demonstrated that green synthesized ZnONPs are significantly more efficient than chemically ones at reducing hyperglycemia regardless of their absorption.

Diabetic Neuropathy of the Retina and Inflammation: Perspectives

A clear connection exists between diabetes and atherosclerotic cardiovascular disease. Consequently, therapeutic approaches that target both diseases are needed. Clinical trials are currently underway to explore the roles of obesity, adipose tissue, gut microbiota, and pancreatic beta cell function in diabetes. Inflammation plays a key role in diabetes pathophysiology and associated metabolic disorders; thus, interest has increased in targeting inflammation to prevent and control diabetes. Diabetic retinopathy is known as a neurodegenerative and vascular disease that occurs after some years of poorly controlled diabetes. However, increasing evidence points to inflammation as a key figure in diabetes-associated retinal complications. Interconnected molecular pathways, such as oxidative stress, and the formation of advanced glycation end-products, are known to contribute to the inflammatory response. This review describes the possible mechanisms of the metabolic changes in diabetes that involve inflammatory pathways.

Exposure to acute waterborne cadmium caused severe damage on lipid metabolism of freshwater fish, revealed by nuclear lipid droplet deposition in hepatocytes of rare minnow

Cadmium (Cd) is a widely distributed aquatic toxic heavy metal with the potential to disrupt fish metabolism; however, more research is needed to clarify the underlying mechanisms. In the present study, rare minnows (Gobiocypris rarus) were used to detect the effects of cadmium on freshwater fish lipid metabolism and its underlying mechanism by histopathological observation, measurement of serum and liver biochemical indexes, and analysis of gene expression in terms of lipid oxidation, synthesis and transport. Here, severe damage, such as cytoplasmic lipid droplet (LD) accumulation, ectopic deposition of LDs, and the appearance of nuclear LDs (nLDs), was detected after exposure to 2.0 mg/L or higher concentrations (2.5 and 2.8 mg/L CdCl₂) for 96 h. Other damage included abnormal increases in rough endoplasmic reticulum (RER) lamellae in a fingerprint or concentric circle pattern and necrosis of hepatocytes, and which was observed in the livers of fish exposed to 2.0 mg/L CdCl_2.. Both hepatic and serum lipids, such as triglycerides and total cholesterol, were significantly increased after exposure to 2.0 mg/L CdCl₂, as was serum lipase (LPS). Hepatic lipase and lipoprotein lipase remained unchanged, in accordance with the unchanged hepatic mRNA transcripts of PPARɑ. Furthermore, the mRNA transcripts of both SCD and SQLE were significantly decreased. Moreover, hepatic and serum low-density and high-density lipoprotein cholesterol showed significant changes, which were accompanied by a significant increase and decrease in hepatic APOAI and APOB100 mRNA levels, respectively. All the results indicate the presence of severe damage to hepatic lipid metabolism and that disrupted lipid transport may play a key role in the accumulation of hepatic LDs. In addition, the hepatic nLDs of nonmammalian vertebrates and their location across the nuclear envelope are intriguing, suggesting that large-size nLDs are a common marker for severe liver damage.

Independent, combine and interactive effects of heavy metal exposure on dyslipidemia biomarkers: A cross-sectional study in northeastern China

Dyslipidemia is a common disease in the older population and represents a considerable disease burden worldwide. Epidemiological and experimental studies have indicated associations between heavy metal exposure and dyslipidemia; few studies have investigated the effects of heavy metal mixture and interactions between metals on dyslipidemia. We recruited 1121 participants living in heavy metal-contaminated and control areas in northeast China from a cross-sectional survey (2017-2019). Urinary metals including chromium (Cr), cadmium (Cd), lead (Pb), and manganese (Mn) and dyslipidemia biomarkers, namely triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels, were measured. The generalized linear model (GLM) was used to explore the association of a single metal with dyslipidemia biomarkers. Bayesian kernel machine regression (BKMR) and multivariable linear regression were performed to explore the overall effect of metal mixture and the interaction between metals on dyslipidemia. Heavy metal mixture was positively associated with LDL-C, TC, and TG and negatively with HDL-C. In multivariable linear regression, Pb and Cd exhibited a synergistic association with LDL-C in the participants without hyperlipemia. Mn-Cd and Pb-Cr also showed a synergistic association with increasing the level of LDL-C in subjects without hyperlipemia. Cd-Cr showed an antagonistic association with HDL-C, respectively. Cr-Mn exhibited an antagonistic association with decreased HDL-C and TG levels. No significant interaction was noted among the three metals. Our study indicated that exposure to heavy metals is associated with dyslipidemia biomarkers and the presence of potential synergistic or antagonistic interactions between the heavy metals.

Single and combined associations of blood lead and essential metals with serum lipid profiles in community-dwelling adults

Background

Although several studies have examined the relationships between lead (Pb) exposure and serum lipid profiles, the associations of the metal mixture, including lead (Pb) and essential metals with lipid profiles, remain unclear.

Objective

To investigate the associations of the metal mixture including Pb and essential metals [magnesium (Mg), manganese (Mn), copper (Cu), iron (Fe), zinc (Zn), and calcium (Ca)] with serum lipid profiles [total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C)], as well as the potential interactions among the metals.

Methods

Nine hundred and ninety-eight Chinese community-dwelling adults completed a questionnaire and underwent checkups of anthropometric parameters, serum lipid profile levels (TC, TG, LDL-C, and HDL-C), and blood metal concentrations (Pb, Mg, Mn, Cu, Fe, Zn, and Ca). The multivariable linear regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were applied to evaluate the single and combined associations of blood Pb and essential metals with serum lipid profiles.

Results

In the multivariable linear regression model, the blood Pb was positively associated with TC, LDL-C, and HDL-C (p < 0.05, all), and the blood Mg were positively associated with serum TC, LDL-C, and Ln TG (p < 0.05, all). In the WQS regression and BKMR models, the metal mixture of blood Pb and the essential metals was positively associated with all of the serum lipid profiles. In addition, an inverse U-shaped association of Pb with Ln TG and the positive interactive effect between blood Pb and Mg levels on TC and LDL-C were found.

Conclusion

The levels of blood Pb, together with the essential metals, especially Mg levels, are suggested to be considered when assessing dyslipidemia risk. However, more evidence is still needed to validate the conclusions.

Low Levels of Serum Zinc Associate with Malnutrition Risk Assessed by the Royal Free Hospital-Nutritional Prioritizing Tool in Cirrhosis

We have clarified that malnutrition risk evaluated by the Royal Free Hospital-Nutritional Prioritizing Tool (RFH-NPT) is prevalent in patients with cirrhosis. Mineral elements (zinc, iron, magnesium, copper, manganese, and calcium) are micronutrients essential for versatile physiological processes and cellular bioactivities. However, the association between these trace elements and integral nutritional status is unclear in decompensated cirrhotics. We collected blood samples from hospitalized patients with cirrhosis, and serum trace element concentrations were examined by inductively coupled plasma mass spectrometry. Association of trace element levels with high malnutrition risk was determined by multivariate logistic regression model. Sera from 141 patients with decompensated cirrhosis were analyzed for a total of six trace element concentrations. No significant differences were observed between high and low/moderate RFH-NPT malnutrition risk groups with the exception of zinc. The serum zinc concentrations were significantly decreased in patients at high malnutrition risk when compared to low/moderate subjects (57.9 vs 68.1 μg/dL, P = 0.006). In terms of receiver operating characteristics curve, zinc < 64 μg/dL represented best discriminative capability with an area of 0.635 (95% CI: 0.542, 0.728). Patients in the group with zinc < 64 μg/dL had elevated RFH-NPT and MELD score, higher proportion of Child-Pugh class C and ascites, higher CRP, lower albumin and sodium than in the group with zinc ≥ 64 μg/dL. Zinc < 64 μg/dL was an independent risk factor for high malnutrition risk. Low levels of serum zinc referring to less than 64 μg/dL were associated with poor integral nutritional status in cirrhosis.

Association between serum zinc level and lipid profiles in children with spinal muscular atrophy

Background and aims

Children with spinal muscular atrophy (SMA) have a high rate of dyslipidaemia, which is a risk factor of vital importance for cardiovascular diseases in adulthood. Studies have demonstrated that the serum zinc level is associated with lipid profiles in the general population as well as in individuals diagnosed with obesity or diabetes. The purpose of this study was to evaluate the relationship between serum zinc level and lipid profiles in children with SMA.

Methods

This cross-sectional study was launched in a tertiary children's medical center in China and involved pediatric patients with SMA under the management of a multidisciplinary team of outpatient services from July 2019 to July 2021. Anthropometric information, general clinical data, serum zinc level, lipid profiles, and body composition data were collected. Multivariate analysis was used for a thorough inquiry on the association between the serum zinc level and lipid profiles.

Results

Among the 112 patients with SMA [median (IQR) age 5.54 years (2.75–8.29), 58.04% female], who fulfilled the inclusion criteria of the study, dyslipidaemia was detected in 60 patients (53.57%). Based on multivariable linear regression, serum zinc level was positively associated with high-density lipoprotein cholesterol (HDL-C; β = 1.63, 95% CI = 0.44–3.22) and apolipoprotein A1 (APO A1; β = 2.94, 95% CI = 0.03–5.85) levels, independently of age, sex, type, activity, percentage of body fat, and body mass index. As the serum zinc level increased by 10 μmol/L, the risk of low APO A1 levels decreased by 35% (OR = 0.65, 95% CI = 0.44–0.97) according to multivariable logistic regression analyses.

Conclusion

Serum zinc concentration was positively correlated with HDL-C and APO A1 levels among children with SMA. We suggest measures to correct the lower level of serum zinc to improve HDL-C and APO A1 levels.

Targeting ferroptosis with miR-144-3p to attenuate pancreatic β cells dysfunction via regulating USP22/SIRT1 in type 2 diabetes

BACKGROUND

Recently, ferroptosis has been implicated in the pathologic process of several diseases including type 2 diabetes mellitus (T2DM). However, molecular mechanisms underlying ferroptosis in T2DM remain obscure.

METHODS

Twenty four mice were included in this study. T2DM model mice were established by a high-fat diet combined with streptozotocin injection. INS-1 cells were stimulated with high glucose (HG). Cell viability was detected by CCK-8 kit. The levels of GSH, MDA, iron, and lipid ROS, and SOD activity, were detected by the corresponding kits. The interaction between miR-144-3p and USP22 was validated by dual-luciferase reporter assay. The relationship between USP22 and its substrate was verified using Co-IP and ubiquitination assays. The mRNA and protein expressions were examined by RT-qPCR and western blot, respectively. The functions of β cells in vitro and in vivo were evaluated glucose-stimulated insulin secretion test and HOMA-β, respectively.

RESULTS

Ferroptosis occurred in the pancreas of T2DM mice and HG-induced INS-1 cells. Silencing miR-144-3p blocked the effect of HG on the cell viability and accumulation of lipid peroxides, thereby improving the insulin secretion in INS-1 cells. Mechanistically, USP22 is a direct target of miR-144-3p, which could stabilize SIRT1 expression, thereby suppressing ferroptosis. Overexpressing USP22 attenuated deleterious roles of HG in INS-1 cells; but its roles were reversed by up-regulating miR-144-3p. In vivo study demonstrated that miR-144-3p antagomir exerted an anti-hyperglycemic effect and regulated the ferroptosis-related proteins in the pancreas.

CONCLUSION

The up-regulation of miR-144-3p suppressed USP22/SIRT1 to induce ferroptosis, which causes pancreatic β cells dysfunction, thereby promoting T2DM development.

Serum Elemental Analysis of Type 2 Diabetes Patients Using SRXRF

A total of 158 serum samples of newly diagnosed type 2 diabetes patients and control subjects were analyzed using Synchrotron Radiation X-ray Fluorescence (SRXRF) technique. The microprobe XRF beam line-16 of Indus-2 synchrotron radiation facility at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, India, was used to identify and quantify the elements K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb. A significant decrease in the mean concentrations of K, Ca, Ti, Cr, Mn, Ni, Zn, and As and an increase in the concentrations of V, Fe, Co, Cu, Se, and Pb were observed in the serum samples of the patient group when compared to the control group. It is hypothesized that the observed alterations in the elemental concentrations might have led to ineffective uptake of insulin and have interfered with glucose homeostasis by either directly or indirectly causing oxidative stress.

Genetically predicted selenium is negatively associated with serum TC, LDL-C and positively associated with HbA1C levels

BACKGROUND & AIMS

Pervious epidemiological evidence on the associations of selenium, zinc with lipid profile and glycemic indices was contradictory. The aim of this study was to investigate whether selenium and zinc were casually associated with lipid profile and glycemic indices using mendelian randomization (MR) analysis.

METHOD

A two-sample MR was used to evaluate the causal-effect estimations. Summary statistics for selenium, zinc, lipids and glycemic indices were retrieved from previous large-scale genome-wide association study (GWAS). Single nucleotide polymorphisms (SNPs) that independently and strongly associated with the selenium and zinc were selected as the instrumental variables. The casual estimates were calculated using inverse variance weighted method (IVW), with weighted median, MR-Egger, and MR-PRESSO test as sensitivity analysis, respectively.

RESULTS

In the standard IVW analysis, per SD increment in selenium was associated with an 0.077 mmol/L decrease of TC (95 %CI: -0.102,-0.052) and 0.074 mmol/L of LDL-C (95 %CI: -0.1,-0.048). Suggestive casual associations were found between selenium and insulin or HbA1c. With IVW method, per SD increase in selenium was associated with an 0.023 mmol/L increase of insulin (95 %CI: 0.001,0.045), and an 0.013 mmol/L increase of HbA1c (95 %CI: 0.003,0.023). The results were robust in the sensitivity analysis. Zinc was not casually associated with any of lipid and glycemic markers.

CONCLUSION

Our MR analysis provides evidence of the potential causal effect of Se on beneficial lipid profile, including decreased TC and LDL-C. Furthermore, suggestive casual evidence was suggested between Se and increased serum HbA1c levels. Careful consideration is required for the protective effects of Se supplementation. No casual-effect association was found between Zn and any indices of the lipid and glucose parameters.

The effect of underlying inflammation on iron metabolism, cardiovascular risk and renal function in patients with type 2 diabetes

Aim

To investigate the impact of inflammation on iron metabolism, cardiovascular risk and renal function in type 2 diabetes (T2D).

Methods

A total of 50 patients with T2D were included in this study. The patients were stratified into two groups based on their levels of C-reactive protein (CRP), namely normal and high levels (n = 25/group). All laboratory tests were measured using standardised methods.

Results

Fasting plasma glucose levels were elevated in patients with high CRP when compared to those with normal levels (p = 0.0413). Total serum iron levels were lower in patients with high CRP levels (12.78 ± 3.50) when compared to those with normal levels (15.26 ± 4.64), p = 0.0381. However, ferritin and transferrin levels were comparable between the groups (p > 0.05). The mean cell volume (MCV) in the high CRP group was lower (87.66 ± 3.62) than the normal level group (90.79 ± 4.52), p = 0.0096, whilst the lipograms were similar (p > 0.05). The estimated glomerular filtration rate (eGFR) was lower in the high CRP group (98.06 ± 11.64) than the normal level group (104.7 ± 11.11), p = 0.046. Notably, CRP levels were negatively associated with serum iron levels (r = -0.38, p = 0.0061), MCV (r = -0.41, p = 0.0031), potassium (r = -0.37, p = 0.0086) and sodium levels (r = -0.28, p = 0.0471). Regression analyses showed that only CRP (β = -0.16, standard error [SE]: 0.06, p = 0.0125) and sodium (β = 0.51, SE: 0.25, p = 0.0434) levels contributed significantly to the prediction of serum iron levels.

Conclusion

Underlying inflammation in T2D is associated with increased incidence of hypertension and reduced levels of serum iron, MCV and renal function. Although there was no apparent clinical anaemia or renal dysfunction in these patients, mitigating inflammation may be effective in circumventing the ultimate development of iron deficiency anaemia and chronic kidney disease in T2D.

Effects of chromium supplementation on lipid profile in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this study was to determine the influence of chromium supplementation on lipid profile in patients with type 2 diabetes mellitus (T2DM).

METHODS

A systematic search was performed in Scopus, Embase, Web of Science, the Cochrane library and PubMed databases to find randomized controlled trials (RCTs) related to the effect of chromium supplementation on lipid profile in patients with T2DM, up to June 2020. Meta-analyses were performed using the random-effects model, and I² index was used to evaluate heterogeneity.

RESULTS

The primary search yielded 725 publications. 24 RCTs (with 28 effect size) were eligible. Our meta-analysis indicated that chromium supplementation resulted in a significant decrease in serum levels of triglyceride (TG) (MD: -6.54 mg/dl, 95 % CI: -13.08 to -0.00, P = 0.050) and total cholesterol (TC) (WMD: -7.77 mg/dl, 95 % CI: -11.35 to -4.18, P < 0.001). Furthermore, chromium significantly increases high-density lipoprotein (HDL) (WMD: 2.23 mg/dl, 95 % CI: 0.07-4.40, P = 0.043) level. However, chromium supplementation did not have significant effects on low-density lipoprotein (LDL) (WMD: -8.54 mg/dl, 95 % CI: -19.58 to 2.49, P = 0.129) level.

CONCLUSION

Chromium supplementation may significantly improve lipid profile in patients with T2DM by decreasing TG and TC and increasing HDL. However, based on our analysis, chromium failed to affect LDL. It should be noted that the lipid-lowering properties of chromium supplementation were small and may not reach clinical importance.

Association of Serum Levels of Zinc, Copper, and Iron with Risk of Metabolic Syndrome

The association between serum concentrations of zinc, copper, or iron and the risk of metabolic syndrome are inconclusive. Therefore, we conduct a case-control study to explore the relationship between serum levels of zinc, copper, or iron and metabolic syndrome as well as each metabolic factor and insulin resistance. We enrolled 1165 adults, aged ≥ 40 (65.8 ± 10) years in a hospital-based population to compare the serum levels of zinc, copper, and iron between subjects with and without metabolic syndrome by using multivariate logistic regression analyses. The least square means were computed by general linear models to compare serum concentrations of zinc, copper, and iron in relation to the number of metabolic factors. The mean serum concentrations of zinc, copper, and iron were 941.91 ± 333.63 μg/L, 1043.45 ± 306.36 μg/L, and 1246.83 ± 538.13 μg/L, respectively. The odds ratios (ORs) of metabolic syndrome for the highest versus the lowest quartile were 5.83 (95% CI: 3.35-10.12; p for trend < 0.001) for zinc, 2.02 (95% CI: 1.25-3.25; p for trend: 0.013) for copper, and 2.11 (95% CI: 1.24-3.62; p for trend: 0.021) for iron after adjusting for age, sex, personal habits, body mass index, and homeostatic model assessment insulin resistance. Additionally, the serum zinc, copper, and iron concentrations increased as the number of metabolic factors rose (p for trend < 0.001). This was the first study to clearly demonstrate that higher serum levels of zinc, copper, and iron were associated with the risk of metabolic syndrome and the number of metabolic factors independent of BMI and insulin resistance.

Current Trends of Essential Trace Elements in Patients with Chronic Liver Diseases

Essential trace elements play crucial roles in the maintenance of health, since they are involved in many metabolic pathways. A deficiency or an excess of some trace elements, including zinc, selenium, iron, and copper, frequently causes these metabolic disorders such as impaired glucose tolerance and dyslipidemia. The liver largely regulates most of the metabolism of trace elements, and accordingly, an impairment of liver functions can result in numerous metabolic disorders. The administration or depletion of these trace elements can improve such metabolic disorders and liver dysfunction. Recent advances in molecular biological techniques have helped to elucidate the putative mechanisms by which liver disorders evoke metabolic abnormalities that are due to deficiencies or excesses of these trace elements. A genome-wide association study revealed that a genetic polymorphism affected the metabolism of a specific trace element. Gut dysbiosis was also responsible for impairment of the metabolism of a trace element. This review focuses on the current trends of four trace elements in chronic liver diseases, including chronic hepatitis, liver cirrhosis, nonalcoholic fatty liver disease, and autoimmune liver diseases. The novel mechanisms by which the trace elements participated in the pathogenesis of the chronic liver diseases are also mentioned.

Role of Minerals and Trace Elements in Diabetes and Insulin Resistance

Minerals and trace elements are micronutrients that are essential to the human body but present only in traceable amounts. Nonetheless, they exhibit well-defined biochemical functions. Deficiencies in these micronutrients are related to widespread human health problems. This review article is focused on some of these minerals and trace element deficiencies and their consequences in diabetes and insulin resistance. The levels of trace elements vary considerably among different populations, contingent on the composition of the diet. In several Asian countries, large proportions of the population are affected by a number of micronutrient deficiencies. Local differences in selenium, zinc, copper, iron, chromium and iodine in the diet occur in both developed and developing countries, largely due to malnutrition and dependence on indigenous nutrition. These overall deficiencies and, in a few cases, excess of essential trace elements may lead to imbalances in glucose homeostasis and insulin resistance. The most extensive problems affecting one billion people or more worldwide are associated with inadequate supply of a number of minerals and trace elements including iodine, selenium, zinc, calcium, chromium, cobalt, iron, boron and magnesium. This review comprises various randomized controlled trials, cohort and case-controlled studies, and observational and laboratory-based studies with substantial outcomes of micronutrient deficiencies on diabetes and insulin resistance in diverse racial inhabitants from parts of Asia, Africa, and North America. Changes in these micronutrient levels in the serum and urine of subjects may indicate the trajectory toward metabolic changes, oxidative stress and provide disease-relevant information.

Exposure to Dichlorodiphenyldichloroethylene (DDE) and Metallothionein Levels in Rats Fed with Normocaloric or High-Fat Diet: A Review

The growing number of studies on metallothioneins (MTs), cysteine-rich metal-binding proteins, have been disclosing new functions of these proteins. Thanks to their inducibility, they were considered to play a pivotal role in regulating trace metals homeostasis and in detoxification from heavy metals; nowadays, it is known that they are involved in various physiological and pathological processes, such as regulation of apoptosis, elimination of free radicals, and protection of nucleic acids against toxic insults. MT induction has been demonstrated following stress factors other than heavy metals, such as endocrine-disrupting chemicals, insecticides, and herbicides. However, retrieved data are often controversial: in some cases, xenobiotics elicit MT expression and synthesis; under different conditions, they lead to a decrease in cellular MT content. This review describes the MT response to dichlorodiphenyltrichloroethane (DDT) contamination in mammalian tissues. In particular, attention focuses on changes in MT expression, synthesis, and localization in rat liver, kidneys, and testes following oral administration of dichlorodiphenyldichloroethylene (DDE), the main metabolite of DDT, under normal dietary conditions or in combination with a high fat diet potentially able to increase the cellular uptake of this lipophilic pesticide. The potential connection between MT expression and synthesis, lipophilic substances and trace metals availability is also discussed.

Zinc, copper, and oxysterol levels in patients with type 1 and type 2 diabetes mellitus

BACKGROUND

The present study has the objective to assess the zinc (Zn), copper (Cu), and oxysterols plasma levels in type 1 (DM1) (n = 26) and type 2 (DM2) (n = 80) diabetes patients, as compared to healthy controls (n = 71), in order to testify whether metal levels may have a significant impact on the association between oxysterols and diabetes.

METHODS

Plasma trace elements and plasma oxysterols were assessed using atomic absorption spectrometry and LC-MS/MS, respectively. Lifestyle, smoking status, alcohol intake, and drug usage, as well as microvascular complications, were also monitored and reported.

RESULTS

The obtained data demonstrated that both DM1 and DM2 patients were characterized by significantly elevated HbA1c, FBG, TC, LDL-C, VLDL-C, and TG levels as compared to controls. Plasma Zn levels and Zn/Cu ratio in DM1 and DM2 patients were about 3- and 2-fold lower than controls. No significant differences in plasma Cu levels were reported. The 7-ketocholesterol (7-kchol) levels in DM1 and DM2 patients exceeded these values in healthy individuals by 2.5 and 5-fold, respectively. Similarly, cholestan-3β, 5α, 6β-triol (chol-triol) levels were more than 3- and 6-fold higher when compared to the respective values in non-diabetic controls. In regression models decreased plasma Zn and elevated oxysterol levels were significantly associated with HbA1c and fasting plasma glucose levels, after adjustment for anthropometric and clinical variables, as well as routine biochemical markers.

CONCLUSIONS

Plasma Zn concentration is inversely associated with both 7-kchol and chol-triol levels. Assessment of Zn and oxysterol levels may be used both for risk assessment and as targets for the treatment of diabetes mellitus.

Mangiferin improves hepatic damage-associated molecular patterns, lipid metabolic disorder and mitochondrial dysfunction in alcohol hepatitis rats

This study was conducted to investigate the beneficial effects and possible mechanism of action of mangiferin (MF) in alcohol hepatitis (AH) rats. Building on our previous study, the damage-associated molecular patterns (DAMPs), lipid metabolic disorder and mitochondrial dysfunction were investigated. MF effectively regulated the abnormal liver function, the levels of alcohol, FFAs and metal elements in serum. More importantly, MF improved the expression levels of mRNA and protein of PPAR-γ, OPA-1, Cav-1, EB1, NF-κB p65, NLRP3, Cas-1 and IL-1β, and decreased the positive protein expression rates of HSP90, HMGB1, SYK, CCL20, C-CAS-3, C-PARP and STARD1. Additionally, MF decreased the levels of fumarate, cAMP, xanthurenic acid and d-glucurone-6,3-lactone, and increased the levels of hippuric acid and phenylacetylglycine, and then adjusted the changes of phenylalanine metabolism, TCA cycle and ascorbate and aldarate metabolic pathways. The above results suggested that MF can effectively prevent AH by modulating specific AH-associated genes, potential biomarkers and metabolic pathways in AH rats, etc.

The Relationship between Dietary, Serum and Hair Levels of Minerals (Fe, Zn, Cu) and Glucose Metabolism Indices in Obese Type 2 Diabetic Patients

The aim of this study was to assess the levels of Zn, Fe and Cu in the serum and hair, and dietary intake of type 2 diabetic patients and their association with glucose and lipid indices. The study was conducted on 62 people aged 40-78 years (31 diabetic patients and 31 healthy subjects, who were the control group). The content of trace elements in the hair and serum was analysed with the AAS method. The serum insulin, HbA1c, glucose, total cholesterol and triacylglycerol concentrations were measured by means of RIA, HPLC and colorimetric methods, respectively. The diabetic patients were found to have significantly higher dietary iron intake, higher hair Fe and lower serum Zn concentrations than the non-diabetic subjects, while the hair Zn and Cu contents were comparable in both groups. The serum Zn and Cu levels of the diabetic subjects were negatively correlated with the serum glucose, the serum Zn and Cu/Zn ratio was inversely correlated with the serum total cholesterol and the serum insulin level was positively associated with the hair Cu/Zn ratio. The results of this study indicate that the trace element status (Zn, Fe, Cu), as reflected in the blood serum and hair, may be disturbed due to metabolic derangement occurring in diabetes.

Oral herbal supplement containing magnesium sulfate improve metabolic control and insulin resistance in non-diabetic overweight patients: A randomized double blind clinical trial

Background: Magnesium deficiency plays a key role in obesity and decreases insulin sensitivity. In our previous study, significant evidence was provided for the contribution of oral Mg supplement that could improve insulin sensitivity and body weight in animal trials. The purpose of the present study was to investigate the effects of an herbal supplement containing 300 mg magnesium sulfate on lipid profile, as well as insulin resistance and secretion in overweight patients. Methods: Seventy overweight non-diabetic volunteers with Body Mass Index (BMI) >28 kg/m2 were included in a randomized double blind placebo-controlled clinical trial (ethic number HUMS REC.1394.57) and registered in Iranian Registry of Clinical Trials (IRCT2012110124756N2 with registration number 24756). They received either placebo or an herbal supplement capsule containing 300 mg magnesium sulfate (MgSO4) for 6 months on a daily basis. Metabolic control, lipid profile and magnesium status were determined at baseline and every three months. Student t-test, repeated measure ANOVA and ANCOVA were used to compare the groups. Results: There was no significant difference between groups before intervention, but daily Mg supplement for 6 months significantly improved fasting insulin level (6.71±0.11 to 6.27±0.3 three months after Mg therapy, p<0.01 vs. 6.41±0.11 in control group (5.83±0.063) six months after Mg therapy, p< 0.0001), HOMA-IR (1.52±0.03 )in control group to 1.36±0.03 after three months Mg therapy, p<0.05 vs 1.37±0.05 in control group to 1.22±0.02 six months after Mg therapy, p< 0.05), high density lipoprotein cholesterol (HDL) (43.57±0.82 in control group to 43.91±1.92 three months after Mg therapy, p<0.001vs 43.57±0.82 in control group to 46±0.88 six months after Mg therapy, <0.01), triglyceride (TG) (163.17±6.1 in control group to 141.2±5.84 six months after g therapy, p<0.05) and low density lipoprotein cholesterol (LDL) (112.62±3.41 in control group to 104.42±2.35 six months after Mg therapy, p<0.05). Conclusion: Oral herbal supplement containing MgSO4 (300 mg/day) could improve plasma insulin level, lipid profile, and insulin resistance in non-diabetic overweight volunteers.

The cross-sectional and longitudinal associations of chromium with dyslipidemia: A prospective cohort study of urban adults in China

Chromium exposure can induce altered lipoprotein metabolism in animals, but the health effects of chromium on dyslipidemia in humans have not been fully evaluated. In this study, we aimed to investigate the cross-sectional and longitudinal effects of urinary chromium on lipid levels and dyslipidemia risk among urban adults from two cities in China. A total of 3762 urban adults from the Wuhan-Zhuhai cohort were included in the initial investigation, and followed up three years later. Urinary chromium concentration was measured at baseline and repeated at follow-up. Associations of urinary chromium concentration with lipid levels and risk of dyslipidemia were analyzed by generalized linear and binary logistic regression models, respectively. We found significant relationships between increased urinary chromium concentration and both reduced triglyceride (TG) level and elevated high-density lipoprotein cholesterol (HDL-C) level at baseline and follow-up. In the cross-sectional analysis, each 1-unit increase in log-transformed urinary chromium was associated with a 0.25 mmol/L decrease in TG and a 0.05 mmol/L increase in HDL-C (P < 0.05); also, downward trends for odds ratios of hyperTG (TG level ≥ 1.7 mmol/L) and hypoHDL-C (HDL-C level < 1.0 mmol/L) were significantly associated with increasing quartiles of urinary chromium (P trend < 0.05). In the longitudinal analysis, each 1-unit increase in log-transformed urinary chromium concentration was associated with a 3% and 6% decrease in the risk of developing hyperTG and hypoHDL-C, respectively (P > 0.05). Our study indicated that significant dose-response relationships between urinary chromium concentration and lipid levels were observed at baseline and at follow-up.

Trace Elements in Saliva as Markers of Type 2 Diabetes Mellitus

To analyze Mg, Ca, and Zn levels in saliva, comparing patients with type 2 diabetes mellitus and a control group of healthy subjects. This transversal, observational, clinical study included a total sample of 147 patients, 74 with type 2 diabetes mellitus and a control group of 73 healthy subjects. Socio-demographic, anthropometric, diabetological, and metabolic variables were registered. Trace elements in non-stimulated basal saliva were measured using inductively coupled plasma mass spectrometry (ICP-MS): Mg, Ca, and Zn. Concentrations of zinc, calcium, and magnesium were significantly higher in the diabetic group than the control group (p < 0.001). A relation was observed between waist circumference and high cardiovascular risk in men (based on two categories: waist circumference < 102 cm; waist circumference ≥ 102 cm), and magnesium levels in saliva (p = 0.003). Magnesium, zinc, and calcium levels in saliva could be useful markers for differentiating patients with type 2 diabetes mellitus from non-diabetics. The salivary magnesium could be used as a marker of high cardiovascular risk when associated with abdominal obesity represented by a waist circumference ≥ 102 cm in men. The present results do suggest that salivary zinc levels could act as a good marker of type 2 diabetes mellitus, in light of zinc's well-known role as a co-marker of insulin and its relationship to carbohydrate metabolism.

Serum trace elements in insulin-dependent and non-insulin-dependent diabetes: a comparative study

BACKGROUND

Diabetes mellitus is associated with imbalance in body trace elements. The aim of the current investigation was to compare the levels of trace elements (Zn, Mg, Mn, Cu, Na, K, Fe, Ca, Cr, and Se) in insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetes.

METHODS

A total of 100 patients with diabetes (40 IDDM and 60 NIDDM) and 50 healthy subjects were recruited in the study from both genders. Biochemical measures include glucose, lipids, and HbA1C.

RESULTS

The results showed that Zn, Mg, Cu and Cr were significant lower in patients with diabetes compared to the control group (P<0.01). In addition, Zn and Cr were significantly lower in IDDM than NIDDM (P<0.05). Moreover, Zn and Mg levels were inversely correlated with HbA1c in IDDM and NIDDM (P<0.05). Zn was inversely correlated with fasting blood glucose in IDDM (P<0.05). Finally, no correlation between trace element levels with BMI was found (P>0.05).

CONCLUSION

Disturbance in trace element profile among IDDM and NIDDM is similar.