Altered metabolism of copper, zinc, and magnesium is associated with increased levels of glycated hemoglobin in patients with diabetes mellitus

Peripheral mitochondrial transplantation alleviates diabetes-associated cognitive dysfunction by suppressing cuproptosis

Mitochondrial dysfunction and neuronal impairment are hallmark features of Diabetes-Associated Cognitive Dysfunction (DACD), mitochondrial transplantation is also a therapeutic intervention for DACD. However, the precise mechanism underlying its therapeutic effects are not fully elucidated. Given that imbalances in copper homeostasis and cuproptosis are associated with various neurodegenerative disorders and diabetic myocardial damage, we hypothesize a role for cuproptosis in the pathogenesis of DACD. We further propose that therapeutic peripheral mitochondrial transplantation may ameliorate DACD by reducing processes of cuproptosis. In this research, the study delved into the expression levels of cuproptosis-associated proteins FDX1, LIAS, and DLAT, as well as the copper content in both type 2 diabetes mellitus (T2DM) mice and primary neuronal cells exposed to high glucose and palmitic acid (HG/Pal). Furthermore, the cognitive capabilities of the mice were evaluated using a series of behavioral tests. The findings revealed that in primary neurons exposed to HG/Pal, the expression of copper levels was elevated, and the levels of FDX1, LIAS, and DLAT were reduced. Post-transplantation of platelet-derived mitochondria (Mito-Plt), a significant reversal of these biomarkers was noted, coincident with an improvement in cognitive deficits in T2DM mice. Significantly, the cuproptosis agonist elesclomol (ES) aggravated these alterations. In summary, the findings collectively suggest a causal connection between DACD and the development of cuproptosis in neurons. The use of exogenous Mito-Plt presents a promising therapeutic approach, capable of rescuing neurons from cuproptosis and thereby potentially alleviating DACD.

Diabetes-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk

AIMS

Diabetes mellitus (DM) links the risk of cardiovascular diseases. Inverse to the enhanced expression of matrix metalloproteinases (MMPs), the development of aortic aneurysm is lower in diabetic population. We examined the hypothesis that DM-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk.

METHODS & RESULTS

By culturing vascular smooth muscle cells (VSMCs) or macrophages with different concentrations of glucose in the medium, we confirmed that high glucose significantly increased the expression of fibronectin and CTGF in VSMCs, and induced MMP2 expression and MMP9 secretion in macrophages. We also established an abdominal aortic aneurysm model in streptozotocin-induced diabetic mice and evaluated aneurysm development six weeks later. Compared to the healthy controls, diabetic mice had significantly lower levels of Zn2+ and Mg2+ in serum and developed significantly smaller sizes of aneurysms with higher expression of fibronectin and CTGF; but dietary zinc supplementation to diabetic mice effectively neutralized these differences. Gelatin zymography assay indicated that the enzymatic digestion activity of MMP2 was changed under different concentrations of ZnSO4 and MgSO4. Clinical data analysis also confirmed that DM, serum Zn2+ level, and aortic aneurysm risk closely correlated with each other.

CONCLUSION

It seems that DM-induced alteration of metal ion levels declines the activity of MMPs to negate aortic aneurysm development. Our data provide novel mechanistical insight and therapeutic strategy for aortic aneurysms.

Copper Deficiency Associated with Glycemic Control in Individuals with Type 2 Diabetes Mellitus

Adequate copper (Cu) status has been associated with improved glycemic control, partly because of its role in reducing oxidative stress through superoxide dismutase (SOD) activity. Thus, the aim was to investigate the relationship between plasma Cu concentration and markers associated with glycemic control in individuals with type 2 diabetes mellitus (T2DM). This observational and cross-sectional study was conducted in individuals with T2DM of both sexes, aged between 19 and 59 years. Plasma Cu levels were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). Fasting glucose and insulin concentrations, C-peptide levels, SOD activity, and glycated hemoglobin (%HbA1c) were measured. Homeostatic model assessments (HOMA%B, HOMA%S, and HOMA-IR) were also performed. Additionally, %body fat and waist circumference were measured, and body mass index was calculated. Participants were categorized based on their plasma Cu concentrations (< 70 µg/dL and ≥ 70 µg/dL). The associations between variables were analyzed using chi-squared or Fisher's test and binary logistic regression models. Statistical significance was set at P < 0.05. Of the 97 participants (74.2% women), 85.5% had Cu deficiency. Cu-deficient individuals showed elevated C-peptide concentrations and HOMA%B values compared to those with adequate Cu levels (2.8 ng/mL vs. 1.8 ng/mL, P = 0.011; and 71.4 vs. 31.0, P = 0.003), respectively. Cu deficiency was associated with insulin resistance (P = 0.044) and decreased likelihood of exceeding the target serum glucose level (OR = 0.147, P = 0.013). However, no significant association was found between SOD activity and plasma Cu concentration. Consequently, Cu deficiency was linked to improved glycemic control, although it was not associated with the other markers.

Effect of Zinc Supplementation on Glycemic Control in Newly Diagnosed Patients With Type 2 Diabetes Mellitus

INTRODUCTION

Diabetes mellitus (DM) is a spectrum of metabolic disorders primarily characterized by elevated blood glucose levels. Type 2 DM (T2DM), the most common form, often requires adjunctive therapies to improve glycemic control and mitigate associated risks. Zinc has been implicated in glucose metabolism and insulin function, prompting this study to evaluate the impact of zinc supplementation on glycemic control in newly diagnosed T2DM patients.

METHODS

A randomized, placebo-controlled trial was conducted involving 80 newly diagnosed T2DM patients. Participants were randomly assigned to receive either zinc supplementation (50 mg/day) or a placebo, in conjunction with standard oral hypoglycemic medication, metformin. Key indicators, including fasting blood glucose (FBG), postprandial blood glucose (PPBG), hemoglobin A1c (HbA1c), and lipid profiles, were measured at baseline and after the 12-month intervention period.

RESULTS

The group receiving zinc supplementation demonstrated significant reductions in FBG, PPBG, and HbA1c levels compared to the placebo group. The mean FBG in the intervention group decreased by 21.52 mg/dL, PPBG decreased by 47.53 mg/dL, and HbA1c decreased by 0.79%. Additionally, zinc supplementation led to notable decreases in low-density lipoprotein (LDL) cholesterol by 25.06 mg/dL, triglycerides by 22.2 mg/dL, and total cholesterol levels by 26.67 mg/dL. However, no significant changes were observed in high-density lipoprotein (HDL) cholesterol, very-low-density lipoprotein (VLDL) cholesterol, or erythrocyte sedimentation rate (ESR).

DISCUSSION

The findings suggest that zinc supplementation may be a beneficial adjunctive therapy in the early management of T2DM, contributing to improved glycemic control and favorable changes in lipid profiles. However, its effect on HDL, VLDL, and ESR was insignificant, indicating the need for further research to better understand the broader implications of zinc in T2DM management.

Trace element status in canine endocrine diseases

A balanced trace element status is essential for the optimal functioning of all organisms. However, their concentrations are often altered in diverse medical conditions. This study investigated the trace element profiles in plasma samples of dogs with endocrine diseases and used chemometric techniques to explore their associations with biochemical data. Thirteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se and Zn) were measured in 40 dogs with hyperadrenocorticism (HAC), 29 dogs with diabetes mellitus (DM), 11 dogs with hypothyroidism (HT) and 30 control dogs using inductively coupled plasma mass spectrometry (ICP-MS). Statistically significant differences were observed for As, Cu, Mo, Se and Zn. In comparison with the control group, the HT patients had higher As and lower Se levels, while the HAC group had higher concentrations of Mo. All three disease groups had higher Cu and Zn concentrations than the control group, with the DM group having higher Cu concentrations and the HAC group higher Zn concentrations than the other endocrinopathy groups. The chemometric analysis revealed distinctive association patterns for discriminating each pathology group and the control group. Moreover, the analysis revealed the following associations: Mo with glucose levels and Cu with fructosamine levels in the DM group, As with cortisol levels in the HAC group, and Se with TT4 levels and As with TSH levels in the HT group. The study findings provide valuable insights into the complex relationships between trace elements and endocrinopathies, elucidating the associations with biochemical markers in these diseases. Larger-scale studies are necessary to fully understand the observed relationships and explore the potential clinical applications.

The Effect of Selenium, Zinc, and their Combined Supplementation on Cardiometabolic Biomarkers-comparing their Effects in the Energy Restriction and High-fat Diet Methods in Obese Rats

INTRODUCTION

The fat distribution in the body determines the risk of cardiometabolic problems such as heart disease and diabetes. Some dietary supplements, such as selenium and zinc, possess lipolytic and anti-angiogenic functions, which may be a useful strategy in reducing the risk of cardiometabolic complications. This study evaluated the effect of zinc (Zn), selenium (Se), and their combined supplementation on cardiometabolic risk factors in male Wistar rats in two nutritional models, including caloric restriction (CR) and high-fat diet (HFD).

METHODS AND MATERIALS

The 48 male Wistar rats were divided into three diet groups (HFD and CR and normal diet (ND)). The HFD group was subdivided into four groups (N=8 rats in each group) that received (HFD+Se), (HFD+Zn), (HFD+Zn+Se), and HFD alone as the control group, respectively. After 8 weeks of intervention, biochemical tests were performed on serum levels, including measurement of lipid profile (triglyceride, Cholesterol, LDL and HDL) and glycemic indices (fasting blood sugar, insulin and insulin sensitivity markers).

RESULTS

The results showed that supplementation significantly improved the lipid profile (P <0.001). A comparison of glucose homeostasis indices in the study groups also showed a significant difference. The serum level of glucose was higher in the HFD group than in the intervention groups (P <0.001). Also, the rate of improvement of lipid profile and glycemic indexes in the group receiving the combination of two supplements showed a better trend than those receiving zinc and selenium alone. However, the values were statistically significant only for glucose homeostasis indices (P <0.001).

CONCLUSION

Although obesity is a multifactorial condition, controlling other risk factors, zinc and selenium and their combined supplementation can lead to promising solutions for the treatment of obesity-induced glucose and lipid homeostasis disorders.

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker on oxidative stress and metabolism of elements in kidney of STZ-induced diabetic rats

In diabetes, increased oxidative stress and impaired trace element metabolism play an important role in the pathogenesis of diabetic nephropathy. The objective of this research was to examine the outcomes of blocking the renin-angiotensin system, using either the angiotensin-converting enzyme inhibitor (ACEI), perindopril, or the angiotensin II type 1 (AT1) receptor blocker, irbesartan, on oxidative stress and trace element levels such as Zn, Mg, Cu, and Fe in the kidneys of diabetic rats that had been induced with streptozotocin. Thirty-two Wistar albino male rats were equally divided into four groups. The first group was used as a control. The second group of rats developed diabetes after receiving a single intraperitoneal dose of STZ. The third and fourth groups of rats had STZ-induced diabetes and received daily dosages of irbesartan (15 mg/kg b.w/day) and perindopril (6 mg/kg b.w/day) treatment, respectively. Biochemical analysis of the kidneys showed a distinct increase in oxidative stress, indicated by heightened levels of malondialdehyde (MDA) and decreased superoxide dismutase (SOD) activities, as well as reduced glutathione (GSH) levels in the kidneys of diabetic rats. In the kidneys of diabetic rats, the mean levels of Fe and Cu were found to be significantly higher than those of the control group. Additionally, the mean levels of Zn and Mg were significantly lower in the diabetic rats compared to the control rats. Both perindopril and irbesartan decreased significantly MDA content and increased SOD activities and GSH levels in the kidneys of rats with diabetes. The Zn and Mg concentrations in the kidneys of diabetic rats treated with perindopril and irbesartan were markedly higher than in untreated STZ-diabetic rats, while the Cu and Fe concentrations were significantly lower. The urinary excretion of rats treated with perindopril and irbesartan showed a pronounced increase in Cu levels, along with a significant reduction in Zn and Mg levels. Although diabetic rats demonstrated degenerative morphological alterations in their kidneys, both therapies also improved diabetes-induced histopathological modifications in the kidneys. Finally, the present results suggest that manipulating the levels of Zn, Mg, Cu, and Fe - either through ACE inhibition or by blocking AT1 receptors - could be advantageous in reducing lipid peroxidation and increasing antioxidant concentration in the kidneys of diabetic rats.

Evaluation of Trace Elements Levels and Construction of Auxiliary Prediction Model in Patients with Diabetes Ketoacidosis in Type 1 Diabetes

Background

Trace elements play an important role in reflecting physical metabolic status, but have been rarely evaluated in diabetes ketoacidosis (DKA). Since clinical biochemical parameters are the first-line diagnostic data mastered by clinical doctors and DKA has a rapid progression, it is crucial to fully utilize clinical data and combine innovative parameters to assist in assessing disease progression. The aim of this study was to evaluate the levels of trace elements in DKA patients, followed by construction of predictive models combined with the laboratory parameters.

Methods

A total of 96 T1D individuals (48 DKA patients) were collected from the First Hospital of Jilin University. Serum calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe) and selenium (Se) were measured by Inductively Coupled Plasma Mass Spectrometry, and the data of biochemical parameters were collected from the laboratory information system. Training and validation sets were used to construct the model and examine the efficiency of the model. The lambda-mu-sigma method was used to evaluate the changes in the model prediction efficiency as the severity of the patient's condition increases.

Results

Lower levels of serum Mg, Ca and Zn, but higher levels of serum Fe, Cu and Se were found in DKA patients. Low levels of total protein (TP), Zn and high levels of lipase would be an efficient combination for the prediction of DKA (Area under curves for training set and validation set were 0.867 and 0.961, respectively). The examination test confirmed the clinical applicability of the constructed models. The increasing predictive efficiency of the model was found with NACP.

Conclusion

More severe oxidative stress in DKA led to further imbalance of trace elements. The combination of TP, lipase and Zn could predict DKA efficiently, which would benefit the early identification and prevention of DKA to improve prognosis.

The Link between Trace Metal Elements and Glucose Metabolism: Evidence from Zinc, Copper, Iron, and Manganese-Mediated Metabolic Regulation

Trace metal elements are of vital importance for fundamental biological processes. They function in various metabolic pathways after the long evolution of living organisms. Glucose is considered to be one of the main sources of biological energy that supports biological activities, and its metabolism is tightly regulated by trace metal elements such as iron, zinc, copper, and manganese. However, there is still a lack of understanding of the regulation of glucose metabolism by trace metal elements. In particular, the underlying mechanism of action remains to be elucidated. In this review, we summarize the current concepts and progress linking trace metal elements and glucose metabolism, particularly for the trace metal elements zinc, copper, manganese, and iron.

Lower serum zinc level is associated with higher fasting insulin in type 2 diabetes mellitus (T2DM) and relates with disturbed glucagon suppression response in male patients

AIMS

Zinc ion can play critical role in glycemic control in diabetes mellitus (DM), contributing to both insulin synthesis and secretion. In this study, we aimed to investigate the level of zinc in diabetic patients and its association with glycemic parameters, insulin, and glucagon level.

METHODS

112 individuals (59 cases of type 2DM and 53 non-diabetic controls) were included in this study. Biochemical parameters (FBG, 2hpp, HbA1C), and zinc level in the serum were measured using colorimetric assays. Insulin and glucagon were measured by ELISA method. HOMA-IR, HOMA-B, reciprocal HOMA-B, and Quicki indices were calculated using appropriate formula. For further analysis, patients were divided into two groups: high (>135.5 μg/dl) and low (<135.5 μg/dl) zinc. Glucagon suppression was considered yes if 2hpp glucagon < fasting glucagon.

RESULTS

Our results showed that serum Zn level in type 2 DM patients was lower than control (P value=0.02). Patients with lower Zn had higher fasting insulin (P value=0.006) and higher β-cell activity index (HOMA-B, p value=0.02), however fasting glucagon and parameters of hyperglycemia (FBG, 2hpp, Hba1C) were not different. Moreover, insulin sensitivity and resistance indices (Quicki, HOMA-IR,1/HOMA-IR) showed non-significantly improved status in high Zn group. We found non-significant association between glucagon suppression and Zn level in both genders (N = 39, p value = 0.07), however, it was significant in males (N = 14, p value = 0.02).

CONCLUSION

Altogether, our results indicated reduced serum Zn in type 2DM can exacerbate hyperinsulinemia and glucagon suppression (only significant in the male), highlighting its importance in type 2DM control.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

Relationship between Regional Distribution of Centenarians and Drinking Water Hardness in the Amami Islands, Kagoshima Prefecture, Japan

People who drink naturally hardened water may experience longevity-enhancing effects. In this study, we investigated water hardness and longevity from both geological and epidemiological perspectives in Japan’s Amami islands, where drinking water is drawn from coralline or non-coralline bedrock. We investigated drinking water hardness, limestone bedrock occupancy, and the centenarian rate (number per 10,000 population) by municipality across four adjacent islands (Amami-Oshima (non-coralline), Tokunoshima, Okinoerabu, and Yoron (predominantly coralline)). Limestone was strongly correlated with water hardness (r = 0.99; p < 0.01), occupying more than 80% of the bedrock where the water was the hardest (Tokunoshima’s Isen municipality: 86.5%; Yoron: 82.9%) and being scarcely detectable in Amami-Oshima (0.0 to 0.2%), where the water was the least hard. The centenarian rate was also strongly correlated with water hardness (r = 0.84, p < 0.01), with the highest figures in Yoron (29.7) and Isen (29.2), and the lowest in Amami-Oshima (0.0 to 12.2). Therefore, we hypothesize a potentially beneficial effect of hard water on longevity when that water is drawn from coralline limestone. Water hardness is determined by the water content of calcium and magnesium and may plausibly influence life expectancy through a preventative effect against cardiovascular disease. Our findings are of interest to current debates about future global access to drinking water and its quality.

Evaluation among trace elements, clinical parameters and type 1 diabetes according to sex: A new sight of auxiliary prediction in negative insulin auto-antibodies population

BACKGROUND

Type 1 diabetes (T1D) exhibited sex-specific metabolic status including oxidative stress with dynamic change of trace elements, which emphasized the importance of the evaluation of trace elements according to sex. Besides, the most significant characteristic, insulin auto-antibodies, could not be found in all T1D patients, which needed the auxiliary prediction of clinical parameters. And it would benefit the early detection and treatment if some high-risk groups of T1D could predict and prevent the occurrence of disease through common clinical parameters. Hence, there was an urgent need to construct more effective and scientific statistical prediction models to serve clinic better. This study aimed to evaluate the sex-specific levels of trace elements and the relationship between trace elements and clinical parameters in T1D, and construct sex-specific auxiliary prediction model combined with trace elements and clinical parameters.

METHODS

A total of 105 T1D patients with negative insulin auto-antibodies and 105 age/sex-matched healthy individuals were enrolled in First Hospital of Jilin University. Inductively Coupled Plasma Mass Spectrometry was performed for the measurement of calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), selenium (Se) in the serum, and the data of clinical parameters were received from medical record system. The lambda-mu-sigma method was used to evaluate the relationship between abnormal clinical parameters and trace elements. Training set and validation set were divided for the construction of predictable models in males and females: clinical parameters model, trace element model and the combined model (clinical parameters and trace elements). Goodness fit test, decision curve analysis and other related statistical methods were used to perform data analysis.

RESULTS

Lower levels of Mg, Ca, Fe in the serum were found in T1D population in females compared with healthy population, while levels of Fe, Zn and Cu of serum in T1D individuals were higher than those of healthy population in males. Levels of serum Mg, Fe and Cu in T1D group were found with significant sex difference for (P < 0.05), and the levels of Fe and Cu in serum of males were higher than those of females, level of serum Mg in males was lower than those of females. Levels of serum Mg and Zn showed fluctuation trend with increased numbers of abnormal clinical parameters (NACP) in males. Serum Zn in females showed consistent elevated trend with NACP; serum Se increased first and then decreased with NACP in males and females. The auxiliary prediction model (Triglyceride, Total protein, serum Mg) was found with the highest predicted efficiency in males (AUC=0.993), while the model in females (Apolipoprotein A, Creatinine, Fe, Se, Zn/Cu ratio) showed the best predicted efficiency (AUC=0.951). The models had passed the verification in validation set, and Chi-square goodness-of-fit test, DCA results both confirmed their satisfactory clinical applicability.

CONCLUSION

Sex-specific difference were found in serum Mg, Fe and Cu in T1D. The combination of triglyceride, total protein and serum Mg for males, and apolipoprotein A, creatinine, Fe, Se, Zn/Cu ratio for females could effectively predict T1D in patients with negative anti-bodies, which would provide alarm for the population with high-risk of T1D and serve the T1D prediction in patients with negative anti-bodies.

Potential Role of Copper in Diabetes and Diabetic Kidney Disease

Copper is a fundamental element for the homeostasis of the body. It is the third most abundant essential transition metal in humans. Changes in the concentration of copper in the blood are responsible for numerous diseases affecting various organs, including the heart, brain, kidneys, and liver. Even small copper deficiencies can lead to the development and progression of several pathologies. On the other hand, excessive exposure to copper can cause toxicity in many human organs, leading to various systemic alterations. In the kidney, increased copper concentration in the blood can cause deposition of this element in the kidneys, leading to nephrotoxicity. One of the most interesting aspects of copper balance is its influence on diabetes and the progression of its complications, such as Diabetic Kidney Disease (DKD). Several studies have shown a close relationship between copper serum levels and altered glycemic control. An imbalance of copper can lead to the progression of diabetes-related complications and impaired antioxidant homeostasis. A high Zinc/Copper (Zn/Cu) ratio is associated with improved renal function and reduced risk of poor glycemic control in patients with type two diabetes mellitus (T2DM). Furthermore, the progression of DKD appears to be related to the extent of urinary copper excretion, while regulation of adequate serum copper concentration appears to prevent and treat DKD. The aim of this review is to evaluate the possible role of copper in DKD patients.

Associations of multiple plasma metals with chronic kidney disease in patients with diabetes

As common contaminants, metals are non-negligible risk factors for diabetes and chronic kidney disease. However, whether there is an association between multiple metals exposure and incident chronic kidney disease (CKD) risk in patients with diabetes is unclear. We conducted a prospective study to evaluate these associations. In total, 3071 diabetics with baseline estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² from the Dongfeng-Tongji cohort were included. We measured baseline plasma concentrations of 23 metals and investigated the associations between plasma metal concentrations and CKD in diabetics using logistic regression, the least absolute shrinkage and selection operator (LASSO), and the Bayesian Kernel Machine Regression (BKMR) models. During average 4.6 years of follow-up, 457 diabetics developed CKD (14.9 %). The three models consistently found plasma levels of zinc, arsenic, and rubidium had a positive association with incident CKD risk in patients with diabetes, while titanium, cadmium, and lead had an inverse correlation. The results of BKMR showed a significant and positive overall effect of 23 metals on the risk of CKD, when all of the metals were above the 50th percentile as compared to the median value. In addition, potential interactions of zinc and arsenic, zinc and cadmium, zinc and lead, titanium and arsenic, and cadmium and lead on CKD risk were observed. In summary, we found significant associations of plasma titanium, zinc, arsenic, rubidium, cadmium, and lead with CKD in diabetes and interactions between these metals except for rubidium. Co-exposure to multiple metals was associated with increased CKD risk in diabetics.

Cadmium acute exposure induces metabolic and transcriptomic perturbations in human mature adipocytes

Obesity is considered as a major public health concern with strong economic and social burdens. Exposure to pollutants such as heavy metals can contribute to the development of obesity and its associated metabolic disorders, including type 2 diabetes and cardiovascular diseases. Adipose tissue is an endocrine and paracrine organ that plays a key role in the development of these diseases and is one of the main target of heavy metal accumulation. In this study, we determined by inductively coupled plasma mass spectrometry cadmium concentrations in human subcutaneous and visceral adipose tissues, ranging between 2.5nM and 2.5µM. We found a positive correlation between cadmium levels and age, sex and smoking status and a negative correlation between Cd and body mass index. Based on cadmium adipose tissue concentrations found in humans, we investigated the effects of cadmium exposure, at concentrations between 1nM and 10µM, on adipose-derived human mesenchymal stem cells differentiated into mature adipocytes in vitro. Transcriptomic analysis highlighted that such exposure altered the expression of genes involved in trace element homeostasis and heavy metal detoxification, such as Solute Carrier Family transporters and metallothioneins. This effect correlated with zinc level alteration in cells and cellular media. Interestingly, dysregulation of zinc homeostasis and transporters has been particularly associated with the development of obesity and type 2 diabetes. Moreover, we found that cadmium exposure induces the pro-inflammatory state of the adipocytes by enhancing the expression of genes such as IL-6, IL-1B and CCL2, cytokines also induced in obesity. Finally, cadmium modulates various adipocyte functions such as the insulin response signaling pathway and lipid homeostasis. Collectively, our data identified some of the cellular mechanisms by which cadmium alters adipocyte functions, thus highlighting new facets of its potential contribution to the progression of metabolic disorders.

Synergistic association of the copper/zinc ratio under inflammatory conditions with diabetic kidney disease in patients with type 2 diabetes: The Asahi Diabetes Complications Study

AIMS/INTRODUCTION

We aimed to study the relationships among the copper (Cu)/zinc (Zn) ratio, inflammatory biomarkers, and the prevalence of diabetic kidney disease (DKD) in patients with type 2 diabetes.

MATERIALS AND METHODS

A cross-sectional study was performed on 651 patients with type 2 diabetes. DKD was defined as a urinary albumin-to-creatinine ratio of ≥30 mg/g creatinine and/or an estimated glomerular filtration rate using cystatin C of < 60 mL/min/1.73 m2 . Areas under the curves (AUCs), cutoff values, and thresholds for detecting DKD were determined for the Cu/Zn ratio, soluble tumor necrosis factor-α receptor 1 (sTNFαR1), and high-sensitivity C-reactive protein (hsCRP). Patients were categorized by each cutoff value of sTNFαR1 and the Cu/Zn ratio. Odds ratios (ORs) and biological interactions for the prevalence of DKD were determined.

RESULTS

DKD was identified in 220 patients. AUC/optimal cutoff values were 0.777/1300 pg/mL for sTNFαR1, 0.603/1.1648 for the Cu/Zn ratio, and 0.582/305 ng/mL for hsCRP. The ORs for DKD were higher, but not significantly, in the sTNFαR1 < 1300 and Cu/Zn ≥ 1.1648 group, significantly higher in the sTNFαR1 ≥ 1300 and Cu/Zn < 1.1648 group (P < 0.0001), and further synergistically elevated in the sTNFαR1 ≥ 1300 and Cu/Zn ≥ 1.1648 group (P < 0.0001) compared with the sTNFαR1 < 1300 and Cu/Zn < 1.1648 group after multivariable adjustment. Levels of sTNFαR1 were significantly higher in the sTNFαR1 ≥ 1300 and Cu/Zn ≥ 1.1648 group than in the sTNFαR1 ≥ 1300 and Cu/Zn < 1.1648 group (P = 0.0006).

CONCLUSIONS

Under an inflammatory initiation signal of elevated serum sTNFαR1 levels, an increase in the Cu/Zn ratio may further exacerbate inflammation and is synergistically associated with a high prevalence of DKD in patients with type 2 diabetes.

Determination of plasma and erythrocyte levels of copper, magnesium and zinc by atomic absorption spectrometry in type-2 diabetes mellitus patients with metabolic syndrome

BACKGROUND AND PURPOSE

Imbalance in blood levels of trace elements is independent risk factor for metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and its complications. This study investigated plasma and erythrocyte levels of copper, magnesium, zinc, and their correlations with biochemical components of the MetS in T2DM patients compared to the healthy controls.

EXPERIMENTAL APPROACH

Forty men recently diagnosed T2DM with MetS without complications and thirty six age-matched healthy controls were enrolled in this cross-sectional study. Plasma and erythrocyte levels of selected elements were measured by graphite furnace atomic absorption spectroscopy.

FINDINGS/RESULTS

The results of the present study showed significantly lower plasma levels of copper, magnesium, and zinc and lower erythrocytes copper in the patients' group compared to the controls; while erythrocyte levels of magnesium and zinc were not significantly different between the two groups. Significant negative correlations were observed between plasma levels of copper with waist and hip circumferences, waist to hip ratio, systolic and diastolic blood pressures, fasting blood glucose, and glycated hemoglobin levels in all subjects; while erythrocyte copper levels showed significant negative correlation with triglyceride, and erythrocyte zinc was positively correlated with diastolic blood pressure and negatively with triglyceride.

CONCLUSION AND IMPLICATIONS

Alterations of trace elements may have a significant role in the pathogenesis of MetS and T2DM patients. It is suggested that the body status of copper, magnesium, and zinc might be significantly correlated with components of MetS in T2DM patients; and plasma copper levels may be correlated with complications of type 2 diabetes mellitus.

Associations between multiple heavy metals exposure and glycated hemoglobin in a Chinese population

BACKGROUND

Heavy metals may play an important role as environmental risk factors in diabetes mellitus. This study aimed to explore the association of HbA1c with As, Cd, Cu, Ni, Pb, and Zn in single-metal exposure and multi-metal co-exposure models.

METHODS

A cross-sectional study involving 3472 participants was conducted. Plasma concentrations of heavy metals were determined by inductively coupled plasma mass spectrometry. We estimated the association of each metal with HbA1c by linear regression. Potential heterogeneities by sex, age, and smoking were investigated, and metal mixtures and interactions were assessed by the Bayesian kernel machine regression (BKMR).

RESULTS

In linear regression, Cu (β = 0.324, p < 0.05) and Ni (β = -0.19, p < 0.05) showed significant association with HbA1c in all participants. In BKMR analyses, all exposure-response relationships were approximately linear. Cu was significantly and positively associated with HbA1c levels in overall participants, women, participants aged 60 years old and above, and nonsmokers. Ni was significantly and negatively associated with HbA1c levels in overall participants. We did not observe the overall effect of plasma metal mixtures on HbA1c or the interaction effect of the metals on HbA1c.

CONCLUSION

Cu was positively correlated with HbA1c, whereas Ni was negatively correlated with HbA1c, when evaluated individually or in a metal mixture. Additional studies are necessary to confirm these correlations and to control for exposure to different metals in the general population.

Assessment of the effects of metformin and glibenclamide on the concentration of selected trace elements in type 2 diabetic patients

Metformin and glibenclamide may have beneficial effects on the levels of trace elements in diabetic patients. The aim of the current study was to assess the effects of metformin and glibenclamide on the concentrations of copper (Cu), zinc (Zn) and magnesium (Mg) in patients with type 2 diabetes mellitus. The metformin-treated patients showed significantly lower serum Cu levels compared with the untreated and glibenclamide groups. In addition, treatment with metformin was associated with a significant increase in serum concentrations of Zn compared to the newly diagnosed patients, whereas it did not show a noticeable alteration in the serum level of Mg. In contrast, the glibenclamide treated group revealed significantly higher Zn and Mg levels compared with the newly diagnosed group, while the serum level of Cu was not significantly modified. In conclusion, treatment with metformin led to a reduction in serum Cu and an increase in serum Zn concentrations, whereas glibenclamide treatment displayed enhancement in serum Zn and Mg levels.

The Association Between Trace Elements and Osmolality in Plasma and Aqueous Humor Fluid in Diabetic Rabbits

Trace element metabolism plays an important role in the formation of diabetes and complications of diabetes. Although trace elements changes in lenses in diabetic cataract and glaucoma formation have been investigated, there were few studies evaluating trace elements levels in plasma and aqueous humor fluid in diabetic and non-diabetic conditions. Therefore, we aimed to investigate zinc (Zn), copper (Cu), and chromium (Cr) levels in plasma and aqueous humor fluids of rabbits in the diabetic rabbit model. New Zealand male rabbits were divided into two groups as control (n = 8), and diabetes (n = 8) induced by alloxane. At the end of the experimental period, the osmolality in blood, plasma, and aqueous humor fluids from rabbits were measured by osmometer and Zn, Cu, and Cr levels in plasma and aqueous humor fluid were measured by inductively coupled plasma-optical emission spectrophotometer (ICP-OES). The osmolality in blood, plasma, and aqueous humor fluid of the diabetic group was significantly increased compared to the control group (respectively p < 0.01, p < 0.001, p < 0.001). It was analyzed that plasma Zn and Cu levels of diabetic rabbits increased significantly (respectively, p < 0.01; p < 0.001), whereas Cr level significantly decreased according to the control group (p < 0.01). It was observed that Cr and Zn levels in aqueous humor fluid in diabetes group decreased (respectively p < 0.001 and p < 0.01), and a significantly increased in Cu level (p < 0.001) compared to the control group. Related with these changes that may occur in the eye due to the measured parameters, we consider that comparative studies of these types of diabetic animal models would be useful in the evaluation of diabetes and its complications.

Zinc as a Drug for Wilson's Disease, Non-Alcoholic Liver Disease and COVID-19-Related Liver Injury

Zinc is the second most abundant trace element in the human body, and it plays a fundamental role in human physiology, being an integral component of hundreds of enzymes and transcription factors. The discovery that zinc atoms may compete with copper for their absorption in the gastrointestinal tract let to introduce zinc in the therapy of Wilson's disease, a congenital disorder of copper metabolism characterized by a systemic copper storage. Nowadays, zinc salts are considered one of the best therapeutic approach in patients affected by Wilson's disease. On the basis of the similarities, at histological level, between Wilson's disease and non-alcoholic liver disease, zinc has been successfully introduced in the therapy of non-alcoholic liver disease, with positive effects both on insulin resistance and oxidative stress. Recently, zinc deficiency has been indicated as a possible factor responsible for the susceptibility of elderly patients to undergo infection by SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic. Here, we present the data correlating zinc deficiency with the insurgence and progression of Covid-19 with low zinc levels associated with severe disease states. Finally, the relevance of zinc supplementation in aged people at risk for SARS-CoV-2 is underlined, with the aim that the zinc-based drug, classically used in the treatment of copper overload, might be recorded as one of the tools reducing the mortality of COVID-19, particularly in elderly people.

Zinc deficiency correlates with severity of diabetic polyneuropathy

OBJECTIVES

There are controversies about the role of zinc in the development of both types 1 and 2 diabetes. The aim of this study was to assess serum zinc level in diabetic patients with and without peripheral neuropathy in comparison to healthy controls and to explore the possible relationship between serum zinc level and severity of peripheral neuropathy.

METHODS

This case control study was conducted on 120 subjects: 40 patients fulfilled the criteria for diagnosis of probable diabetic polyneuropathy (DPN), 40 diabetic patients without polyneuropathy (N-DPN) and 40 healthy controls. DPN patients were submitted to clinical assessment of diabetic neuropathy using neuropathy symptom and change (NSC) scale, Michigan Neuropathy Screening Instrument Physical Assessment (MNSI) scale and electrophysiological assessment using nerve conduction study. Zinc serum level was measured in all subjects included in this study using direct colorimetric test method.

RESULTS

Diabetic patients with and without neuropathy were found to have significantly lower mean values of serum zinc than healthy controls (p = .025,  .03 respectively). There is a statistically significant negative correlation between zinc serum level and hemoglobin A1C (HA1C) (p ˂ .001), NSC score (p = .001) and MNSI score (p = .003) in DPN group. There were also statistically significant correlations between zinc serum level and nerve conduction study values.

CONCLUSION

Zinc deficiency significantly correlates with the severity of DPN and glycemic control.

Exocrine pancreas functions in children with type 1 diabetes mellitus

BACKGROUND AND STUDY AIM

We evaluated exocrine pancreas functions using a noninvasive indicator in a case-control study conducted on children and adolescents diagnosed with type 1 diabetes mellitus.

PATIENTS AND METHODS

Sixty-seven patients who participated in a summer camp were enrolled in this study. Nineteen healthy children in the same age group were assigned to the control group. Fecal pancreatic elastase was assayed using the enzyme-linked immunosorbent assay technique. Values higher than 200 µg/g were considered an indication of sufficient exocrine pancreatic functioning, values between 100 µg/g and 200 µg/g were considered mild exocrine pancreatic insufficiency, and values below 100 µg/g were considered severe exocrine pancreatic insufficiency.

RESULTS

The mean concentration of fecal elastase was 158.38 ± 59.67 µg/g. The patients were assigned to three groups according to these values. Thirteen patients (22%) had sufficient fecal elastase levels, whereas 36 patients (62%) had mildly insufficient levels, and nine patients (16%) had severely insufficient fecal elastase concentrations. The levels of fecal elastase, amylase, lipase, and zinc were significantly different between the patients and controls (p < 0.001). Only the duration of diabetes was significantly different between patients with different severities of exocrine pancreatic insufficiency (p = 0.037). Additionally, the group with severe pancreatic insufficiency had more frequent hypoglycemic attacks.

CONCLUSION

Exocrine pancreatic insufficiency may develop in children with diabetes, and hypoglycemia attacks are observed more frequently depending on the severity of pancreatic insufficiency.

The Association between Zinc and Copper Circulating Levels and Cardiometabolic Risk Factors in Adults: A Study of Qatar Biobank Data

Cardiometabolic risk (CMR) factors increase the likelihood of developing cardiovascular diseases (CVD). In Qatar, 24% of the total deaths are attributed to CVDs. Several nutritional disturbances have been linked to high risk of CVD. Many studies have discussed the effects of zinc (Zn) and copper (Cu) on CMR factors; however, evidence has been controversial. This investigated the association between CMR factors and the status of Zn and Cu, in addition to Zn/Cu ratio. A total of 575 Qatari men and women aged 18 years and older were obtained from Qatar Biobank. Plasma levels of Zn and Cu were determined using inductively coupled plasma mass spectrometry (ICP-MS). Anthropometric data and CMR factors were determined using standard methods. Adjusted associations between trace minerals and CMR were estimated by logistic regression. Partial correlation was performed to test the strength of the associations. Zn was not strongly correlated (p-value ˃ 0.01) or significantly associated with CMR factors and metabolic syndrome (MetS). Cu levels correlated positively with body mass index (BMI) (0.23; p ˂ 0.001), pulse rate (PR) (0.18; p ˂ 0.001), total cholesterol (0.13; p = 0.01), and high-density lipoproteins (HDL) (0.27; p ˂ 0.001); and negatively with diastolic blood pressure (DBP) (−0.13; p = 0.01). High plasma Cu significantly decreased the risk of metabolic syndrome (MetS) (0.121; p ˂ 0.001). Furthermore, Zn/Cu ratio positively correlated with waist circumference (0.13; p = 0.01), systolic blood pressure (0.13; p ˂ 0.01), and DBP (0.14; p ˂ 0.01); and negatively with BMI (−0.19; p ˂ 0.001), PR (−0.17; p ˂ 0.001), and HDL (−0.27; p ˂ 0.001). High Zn/Cu ratio increased the prevalence of low HDL (4.508; p ˂ 0.001) and MetS (5.570; p ˂ 0.01). These findings suggest that high plasma Cu levels are associated with a protective effect on DBP, HDL and MetS and that high plasma Zn/Cu ratio is associated with the risk of having low HDL and MetS.

Dietary Copper/Zinc Ratio and Type 2 Diabetes Risk in Women: The E3N Cohort Study

The serum copper (Cu) to zinc (Zn) ratio could be an important determinant of Type 2 diabetes (T2D) risk, but prospective epidemiological data are scarce. We aimed to investigate the association between T2D incidence and the dietary Cu/Zn ratio. A total of 70,991 women from the E3N cohort study were followed for 20 years. The intakes of copper and zinc were estimated at baseline using a validated food frequency questionnaire. We identified and validated 3292 incident T2D cases. Spline analysis showed that a Cu/Zn ratio < 0.55 was associated with a lower risk of T2D. Subgroup analyses comparing women in the highest versus the lowest quintile of Cu/Zn ratio showed the same pattern of association for obese women and those with zinc intake ≥8 mg/day. However, for women with zinc intake <8 mg/day, higher Cu/Zn ratio appeared to be associated with higher T2D risk. Our findings suggest that a lower dietary Cu/Zn ratio is associated with a lower T2D risk, especially among obese women and women with zinc intake >8 mg/day. Further studies are warranted to validate our results.

Protein posttranslational modification (PTM) by glycation: Role in lens aging and age-related cataractogenesis

Crystallins, the most prevalent lens proteins, have no turnover throughout the entire human lifespan. These long-lived proteins are susceptible to post-synthetic modifications, including oxidation and glycation, which are believed to be some of the primary mechanisms for age-related cataractogenesis. Thanks to high glutathione (GSH) and ascorbic acid (ASA) levels as well as low oxygen content, the human lens is able to maintain its transparency for several decades. Aging accumulates substantial changes in the human lens, including a decreased glutathione concentration, increased reactive oxygen species (ROS) formation, impaired antioxidative defense capacity, and increased redox-active metal ions, which induce glucose and ascorbic acid degradation and protein glycation. The glycated lens crystallins are either prone to UVA mediated free radical production or they attract metal ion binding, which can trigger additional protein oxidation and modification. This vicious cycle is expected to be exacerbated with older age or diabetic conditions. ASA serves as an antioxidant in the human lens under reducing conditions to protect the human lens from damage, but ASA converts to the pro-oxidative role and causes lens protein damage by ascorbylation in high oxidation or enriched redox-active metal ion conditions. This review is dedicated in honor of Dr. Frank Giblin, a great friend and superb scientist, whose pioneering and relentless work over the past 45 years has provided critical insight into lens redox regulation and glutathione homeostasis during aging and cataractogenesis.

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.

Plasma metals and cancer incidence in patients with type 2 diabetes

There is limited evidence on the relationships between plasma levels of multiple metals and risk of incident cancer in patients with type 2 diabetes mellitus (T2DM). We examined the associations between plasma levels of 12 metals (iron, copper, zinc, selenium, chromium, manganese, molybdenum, cobalt, nickel, arsenic, cadmium, and lead) and cancer risk in 4573 T2DM patients using Cox proportional hazards models. With a median follow-up of 10.2 years, 541 incident cancers were identified. The multiple-metals model revealed that each 1-SD increase in ln-transformed plasma copper (HR: 1.14; 95%CI: 1.02, 1.27) and lead (HR:1.20; 95%CI:1.03, 1.39) were significantly associated with increased cancer incidence while each 1-SD increase in ln-transformed plasma zinc (HR: 0.82; 95%CI: 0.71, 0.96) and chromium (HR: 0.88; 95%CI: 0.82, 0.94) were significantly associated with decreased cancer incidence. When all participants were further stratified into four subgroups by the quartile levels (Q1-4) of plasma metals, manganese showed significant positive associations with cancer incidence in the upper two quartiles (P trend = 0.003) while nickel showed significant negative associations with cancer incidence in Q2 and 4 groups (P trend = 0.033) compared with participants in Q1 group. Collectively, monitoring of metal levels in diabetic patients needs to be strengthened, which is of great significance for the prevention of incident cancer.

Emerging Roles of Metallothioneins in Beta Cell Pathophysiology: Beyond and Above Metal Homeostasis and Antioxidant Response

Simple Summary

Defective insulin secretion by pancreatic beta cells is key for the development of type 2 diabetes but the precise mechanisms involved are poorly understood. Metallothioneins are metal binding proteins whose precise biological roles have not been fully characterized. Available evidence indicated that Metallothioneins are protective cellular effectors involved in heavy metal detoxification, metal ion homeostasis and antioxidant defense. This concept has however been challenged by emerging evidence in different medical research fields revealing novel negative roles of Metallothioneins, including in the context of diabetes. In this review, we gather and analyze the available knowledge regarding the complex roles of Metallothioneins in pancreatic beta cell biology and insulin secretion. We comprehensively analyze the evidence showing positive effects of Metallothioneins on beta cell function and survival as well as the emerging evidence revealing negative effects and discuss the possible underlying mechanisms. We expose in parallel findings from other medical research fields and underscore unsettled questions. Then, we propose some future research directions to improve knowledge in the field.

Abstract

Metallothioneins (MTs) are low molecular weight, cysteine-rich, metal-binding proteins whose precise biological roles have not been fully characterized. Existing evidence implicated MTs in heavy metal detoxification, metal ion homeostasis and antioxidant defense. MTs were thus categorized as protective effectors that contribute to cellular homeostasis and survival. This view has, however, been challenged by emerging evidence in different medical fields revealing novel pathophysiological roles of MTs, including inflammatory bowel disease, neurodegenerative disorders, carcinogenesis and diabetes. In the present focused review, we discuss the evidence for the role of MTs in pancreatic beta-cell biology and insulin secretion. We highlight the pattern of specific isoforms of MT gene expression in rodents and human beta-cells. We then discuss the mechanisms involved in the regulation of MTs in islets under physiological and pathological conditions, particularly type 2 diabetes, and analyze the evidence revealing adaptive and negative roles of MTs in beta-cells and the potential mechanisms involved. Finally, we underscore the unsettled questions in the field and propose some future research directions.

Regulation of divalent metal ions to the aggregation and membrane damage of human islet amyloid polypeptide oligomers

The accumulation of human islet amyloid polypeptide (hIAPP) on the surface of pancreatic β cells is closely related to the death of the cells. Divalent metal ions play a significant role in the cytotoxicity of hIAPP. In this study, we examined the roles played by the divalent metal ions of zinc, copper and calcium in the aggregation of both hIAPP18-27 fragment and full-length hIAPP and the ability of their oligomers to damage the membrane of POPC/POPG 4 : 1 LUVs using the ThT fluorescence, TEM, AFM, CD, ANS binding fluorescence and dye leakage experiments. We prepared metal-free and metal-associated oligomers that are similar in size and aggregate slowly using the short peptide and confirmed that the ability of the peptide oligomers to damage the lipid membrane is reduced by the binding to the metal ions, which is closely linked to the reducing hydrophobic exposure of the metal-associated oligomers. The study on the full-length hIAPP showed that the observed membrane damage induced by hIAPP oligomers is either mitigated at a peptide-to-metal ratio of 1 : 0.33 or aggravated at a peptide-to-metal ratio of 1 : 1 in the presence of Zn(ii) and Cu(ii), while the surface hydrophobicity of hIAPP oligomers was reduced at both peptide-to-metal ratios. The observed results of the membrane damage were attributed to the counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the binding of the metal ions to hIAPP oligomers. The former could play a predominant role in reducing the membrane damage at a peptide-to-metal ratio of 1 : 0.33, while the latter could play a predominant role in enhancing the membrane damage at a peptide-to-metal ratio of 1 : 1. This study shows that an enhanced membrane damage could be caused by the oligomer species with a decreased instead of an increased disruptive ability, given that the abundance of the oligomer species is high enough.

Their is a counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the metal binding in the activity of hIAPP induced membrane damage.

Functionality of receptor targeted zinc-insulin quantum clusters in skin tissue augmentation and bioimaging

Quantum clusters with target specificity are suitable for tissue-specific imaging. In the present work, amorphous zinc insulin quantum clusters (IZnQCs) had been synthesised to promote and monitor wound recovery. Easy synthesis, biocompatibility, stability, enhanced quantum yield, and solubility made the cluster suitable for preclinical/clinical exploration. Zn²⁺ is known for its binding to insulin hexamer. Here we report the reformation of the structure in a quantum cluster form in the presence of Zn²⁺. The formation of IZnQCs was confirmed by the change in zeta potential from -25.6 mV to -17.9 mV and also the formation of protein metal interaction was confirmed in FTIR bands at 450, 480, and 613 cm^-1 for Zn-O, Zn-N, and Zn-S, respectively. HRTEM-EDS and SAED data analysis showed an amorphous nature of the cluster. The binding of IZnQCs to the cells has been confirmed using confocal microscopy. IZnQCs showed a synergistic effect in wound recovery than insulin or Zn²⁺ alone. Further due to high fluorescence this recovery process can be monitored under an appropriate setup. Wound healing promotional activity, target specificity, and fluorescence properties make the IZnQCs ideal to use for bioimaging along with promoting and monitoring of wound recovery agent.

Possible Associations of Disturbed Neurometals and Ammonia with Glycaemic Control in Type 1 Diabetic Children with Attention Deficit Hyperactivity Disorder

The chronicity of type 1 diabetes mellitus (T1DM) is reported to be associated with various psychological disorders. The current study aimed to evaluate the levels of serum ammonia and various neurometals (zinc, copper, and magnesium) in patients with T1DM with and without ADHD and to correlate their levels with glycaemic status. A prospective case-control study was conducted with 60 diabetic children with T1DM (allocated into a group of 20 patients with a diagnosis of ADHD and a group of 40 patients without ADHD) who were comparable to 60 matched controls. Assays of glucose, glycated haemoglobin (HbA1c), ammonia, zinc, copper, and magnesium were performed. Overall, ammonia and copper levels were significantly higher in the diabetic patients especially those with ADHD than in the control group (p ˂ 0.05 for all). The calculated copper/zinc ratio was significantly higher in the diabetic patient group than in the control group and higher in diabetic children with ADHD than in diabetic children without ADHD (p ˂ 0.05 for all). Diabetic children had significantly lower magnesium levels than the controls (p ˂ 0.05), but no significant difference between the diabetic subgroups was detected. A positive correlation between glycaemic control (HbA1c %) and ammonia level was found in the diabetic group and subgroups, and a positive correlation was found between HbA1c % and the Cu/Zn ratio in diabetic children with ADHD (p ˂ 0.05 for all). The current study confirms an association of elevated ammonia and copper/zinc ratio with poor glycaemic control and ADHD development among children with T1DM.

Serum zinc level and hepatic fibrosis in patients with nonalcoholic fatty liver disease

This study aimed to investigate the relationship between serum zinc level and hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). A cross-sectional study was conducted using nationally representative samples from the Korea National Health and Nutrition Examination Survey 2010. Significant hepatic fibrosis was defined as Fibrosis-4 (FIB-4) index>1.3. Zinc level was measured using inductively coupled plasma mass spectrometry. Univariable and multivariable logistic regression analyses were performed to assess risk factors for significant hepatic fibrosis in patients with NAFLD. A total of 300 patients with NAFLD were analyzed in this study. The mean serum zinc level was 139.8±29.9 μg/dL. FIB-4 index was significantly increased as the serum zinc level decreased (Adjusted correlation coefficient = -0.177, p = 0.003). Significant liver fibrosis was observed in 62 patients (21%). The multivariable analysis showed that significant liver fibrosis in NAFLD was associated with diabetes mellitus (odds ratio [OR], 3.25; 95% confidence interval [CI], 1.71–6.19; p<0.001), male (OR, 2.59; 95% CI, 1.31–5.12; p = 0.006), and zinc level <140 μg/dL (OR, 2.14; 95% CI, 1.16–3.94; p = 0.015). There was an inverse relationship between serum zinc level and FIB-4 index in NAFLD. Low levels of serum zinc were an independent risk factor for significant hepatic fibrosis in NAFLD.

Association between urinary metals levels and metabolic phenotypes in overweight and obese individuals

Epidemiologic studies suggest that circulating metals from the natural environment are linked with cardiometabolic health. However, few studies examined the relationship between multiple metals exposure and metabolic phenotypes, especially in obese individuals. We conducted a cross-sectional study to explore the association between 23 urinary metals and metabolic phenotypes in 1392 overweight and obese individuals (592 males, 800 females, mean age 43.1 ± 9.8 years). Participants were classified as metabolically unhealthy if they had ≥2 of the following metabolic abnormalities: elevated blood pressure, elevated fasting blood glucose, elevated triglycerides, and reduced high-density lipoprotein cholesterol. Odds ratios (ORs) of unhealthy metabolic phenotypes for metal levels categorized into tertiles were assessed using logistic regression models. Five metals (barium, copper, iron, uranium, and zinc) were associated with unhealthy metabolic phenotypes in single-metal models, while in the multiple-metal model, only zinc and zinc-copper ratio remained significant. The ORs (95% CIs) comparing extreme tertiles were 2.57 (1.69, 3.89) for zinc and 1.68 (1.24, 2.27) for zinc-copper ratio after adjustment for confounders (both p-trends were <0.001). The numbers of metabolic abnormalities significantly increased with the levels of zinc and the zinc-copper ratio increased. Similar associations were observed with metabolic syndrome risk. High levels of urinary zinc were positively associated with elevated fasting blood glucose (p-trend < 0.001) and elevated triglycerides (p-trend = 0.003). The results suggest that urinary zinc and zinc-copper ratio are positively associated with increased risk of unhealthy metabolic phenotype. Further prospective studies with a larger sample size are required to verify these findings.

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.

Chromium(III) Glycinate Complex Supplementation Improves the Blood Glucose Level and Attenuates the Tissular Copper to Zinc Ratio in Rats with Mild Hyperglycaemia

The aim of the study was to evaluate the hypoglycaemic potential of supplementary Cr in the form of chromium(III) glycinate (CrGly) in the diabetic model of rats. The experiment was conducted on 40 male Wistar rats, of which 30 were made diabetic by injection of a single dose of streptozotocin (55 mg/kg b.m.), while the remaining 10 rats served as the healthy control. After inducing hyperglycaemia, 2 groups of diabetic rats (10 rats each) were supplemented with Cr either as CrGly or chromium(III) picolinate (CrPic) given orally at a dose of 10 mg/kg diet (about 0.75 mg Cr/kg b.m.) with adequate AIN-93M diet for 7 weeks. At the termination of experiment, all animals were sacrificed to collect blood and internal organs for biochemical assays. Blood biochemical indices and tissular trace element contents (Fe, Zn, Cu, Cr) were measured and compared with the values of the untreated groups. It was found that CrGly significantly decreased blood glucose, total cholesterol, HDL cholesterol and triacylglycerol levels more efficiently than CrPic. Furthermore, both Cr compounds normalized disturbed the serum, renal and cardiac molar Cu/Zn ratio, as well as restored the kidney Zn and Cu levels in rats with hyperglycaemia. Supplementary Cr did not increase the tissular Cr levels in diabetic rats. The study confirmed the hypoglycaemic potential of CrGly in the diabetic model of rats.

Tauroursodeoxycholate-Bile Acid with Chaperoning Activity: Molecular and Cellular Effects and Therapeutic Perspectives

Tauroursodeoxycholic acid (TUDCA) is a naturally occurring hydrophilic bile acid that has been used for centuries in Chinese medicine. Chemically, TUDCA is a taurine conjugate of ursodeoxycholic acid (UDCA), which in contemporary pharmacology is approved by Food and Drug Administration (FDA) for treatment of primary biliary cholangitis. Interestingly, numerous recent studies demonstrate that mechanisms of TUDCA functioning extend beyond hepatobiliary disorders. Thus, TUDCA has been demonstrated to display potential therapeutic benefits in various models of many diseases such as diabetes, obesity, and neurodegenerative diseases, mostly due to its cytoprotective effect. The mechanisms underlying this cytoprotective activity have been mainly attributed to alleviation of endoplasmic reticulum (ER) stress and stabilization of the unfolded protein response (UPR), which contributed to naming TUDCA as a chemical chaperone. Apart from that, TUDCA has also been found to reduce oxidative stress, suppress apoptosis, and decrease inflammation in many in-vitro and in-vivo models of various diseases. The latest research suggests that TUDCA can also play a role as an epigenetic modulator and act as therapeutic agent in certain types of cancer. Nevertheless, despite the massive amount of evidence demonstrating positive effects of TUDCA in pre-clinical studies, there are certain limitations restraining its wide use in patients. Here, molecular and cellular modes of action of TUDCA are described and therapeutic opportunities and limitations of this bile acid are discussed.

Altered serum Zinc and Copper in Iranian Adults who were of normal weight but metabolically obese

Metabolically obese normal weight (MONW) individuals are potentially at increased risk of developing metabolic syndrome. Serum zinc and copper concentrations were assessed in individuals with MONW to determine whether MONW is associated with altered serum zinc and/or copper status. Normal weight subjects (total n = 2419; 1298 men and 1121 women), were recruited as part of Mashhad Stroke and Heart Association Disorder (MASHAD) Study cohort. They were divided into two groups according to the presence or absence of MetS, defined using IDF criteria. Serum zinc and copper concentrations were determined by atomic absorption. Of the 2419 normal weight adults, 377 had MetS. Of this group, 53.7% and 49.7% had a serum zinc <70 µg/dl (Q1) (p = 0.001) or a serum copper <79 µg/dl (Q1) respectively. Furthermore, 27.3% had a serum copper >131 µg/dl (Q4) (p = 0.034), and 18.8% had a serum zinc >95 µg/dl (Q4). Logistic regression analysis was performed to determine the odds ratio (OR) for an association of serum zinc, copper and zinc to copper ratio with MetS in normal weight subjects. The subjects with a serum zinc >95 µg/dl (Q4) had 0.386 [OR: 0.614(95%CI 0.457–0.823)] lower chance of MetS (p = 0.001) and the subjects with a serum copper >131 (Q4) had OR 1.423 (95% CI: 1.09–1.857) higher chance of MetS (p = 0.009). These data remained significant after adjustment for age and sex, for serum zinc and copper, respectively. Furthermore, our results strongly suggested that zinc and copper were the independent risk factor for metabolic syndrome in normal weight subjects. There is an imbalance between serum copper and zinc concentrations among individuals with MONW when compared with normal BMI individuals without MetS. This may increase the risk of individuals with MONW developing conditions associated with this imbalance, such as diabetes and cardiovascular disease.

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.

Oxidative stress in cervical cancer and its response to chemoradiation

Objectives:

Cervical cancer (CaCx) is one of the leading causes of cancer-related death among women worldwide, with the great social and economic burden. Diagnoses in early stages can decrease mortality and morbidity rates. This study was conducted to evaluate the status of serum total antioxidant capacity (TAC), and malondialdehyde (MDA) and copper concentrations among patients with CaCx to determine the level of oxidative stress and effect on which of chemoradiation.

Materials and Methods:

Fifty patients with histopathologically proven CaCx who visited the department of oncology & gynaecology and 50 age-matched healthy females were selected for the study. Serum TAC, MDA, and copper were estimated in both study groups. The effect of chemoradiation on these was estimated in patients with CaCx.

Results:

The mean ± standard deviation age of the patients was 43.98±6.38 years, whereas that of the controls was 31.56±6.84 years. The mean serum copper and MDA concentrations in the patients was significantly higher as compared with the controls, whereas the mean TAC in the patients was reduced when compared with the controls. After chemoradiation, there was a significant increase and decrease in TAC and MDA, respectively, after chemoradiotherapy, whereas the changes in the copper concentrations were insignificant.

Conclusion:

These results suggest that patients with CaCx were in oxidative stress because the oxidative parameters in serum (copper, MDA) were increased and the defensive TAC was decreased in patients with CaCx and chemoradiotherapy improved their anti-oxidant capacity. Further studies are needed to evaluate the concurrent use of antioxidants with chemoradiotherapy for improving the disease prognosis.

Oral Supplementation Effect of Iron and its Complex Form With Quercetin on Oxidant Status and on Redistribution of Essential Metals in Organs of Streptozotocin Diabetic Rats

Background and aims: Quercetin, is a polyphenolic antioxidant compound. It is able to form complex with metal ions such as iron and exerts a broad range of biological activities like improving metabolic disorders. This research aims at investigating the effect of oral supplementation of iron (2.5mg Fe/Kg/day) and its complex form (molar ratio 1:5; 2.5mg/25mg/Kg/day) with quercetin (25mg/Kg/day) on lipid metabolism, oxidant status and trace elements contents in organs of Wistar diabetic rats (45 mg/kg/rat.ip of streptozotocin) during eight weeks of experimentation.

Material and method: To achieve this, liver and adipose tissue enzymes activities, NO • , O2 −• , TBARs, carbonyl protein levels in plasma were analysed. Metals (Cu, Fe, Mg, Zn) analysis of organs were determined by inductively coupled plasma atomic emission spectroscopy.

Results: Iron supplemented alone induced a noticeable disorder in lipid, lipoprotein, lipases and oxidant status. Yet, it caused an imbalance in the redistribution of metals in the organs of diabetic and non diabetic rats. Iron-quercetin complex was shown as less harmful and more beneficial than iron supplemented alone.

Conclusions: This complex could reverse oxidative stress and iron deficiency mostly caused by the diabetic disease but at the same time it induces an imbalance in redistribution of other essential metals.

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.

Interactions between plasma copper concentrations and SOD1 gene polymorphism for impaired glucose regulation and type 2 diabetes

Aims

To examine the associations of plasma copper concentrations and superoxide dismutase 1 (SOD1) polymorphisms as well as their gene-environment interaction with newly diagnosed impaired glucose regulation (IGR) and type 2 diabetes (T2D).

Methods

We performed a large case-control study in 2520 Chinese Han subjects: 1004 newly diagnosed T2D patients, 512 newly diagnosed IGR patients and 1004 individuals with normal glucose tolerance.

Results

After multivariable adjustment, the ORs (95% CIs) of T2D across tertiles of plasma copper were 1.00 (reference), 1.85 (95% CI: 1.39, 2.45), and 4.21 (95% CI: 3.20, 5.55) (P-trend < 0.001). Each SD increment of ln-transformed plasma copper was associated with 104% higher odds (OR 2.04, 95%CI 1.82–2.28) increment in ORs of T2D. Meanwhile, compared with the GG genotype of rs2070424, the OR of T2D associated with AG and AA genotypes were 1.44 (95% CI 1.15–1.81) and 1.74 (95% CI 1.33–2.28), respectively. In addition, the positive association between plasma copper and T2D was modified by rs2070424 genotypes. The adjusted ORs and 95% CIs of T2D per SD increment of ln-transformed plasma copper were 2.40 (1.93–2.99), 1.85 (1.59–2.16) and 1.76 (1.44–2.15) in rs2070424 GG, AG and GG carriers respectively (P for interaction < 0.05). Similar interactions were also found for IGR and IGR&T2D. When the joint effects were examined, individuals with rs2070424 AA genotype and the highest tertile of plasma copper concentration had a much higher risk of IGR&T2D (OR 5.34, 95% CI 3.48–8.21) than those with rs2070424 GG genotype and the lowest tertile of plasma copper concentrations.

Conclusions

Plasma copper concentrations are positively and significantly associated with IGR as well as T2D, and these associations may be modified by SOD1 polymorphism. Further studies are warranted to elucidate the potential mechanisms.

•

Plasma copper concentrations are positively and significantly associated with IGR as well as T2D.

•

Compared with the GG genotype of rs2070424, the risk of T2D associated with AG and AA genotypes were higher.

•

The associations between copper and T2D as well as IGR may be modified by SOD1 rs2070424 polymorphism.

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Evaluating the interaction of copper and gene polymorphisms may shed etiologic insight into the copper-diabetes relation.

Association between zinc nutritional status and glycemic control in individuals with well-controlled type-2 diabetes

BACKGROUND/OBJECTIVE

Interest in healthy properties of food and nutrients as co-adjuvant in type-2 diabetes therapy has increased in recent years. Zinc supplementation trials have shown improvements in glycemic control in these patients, although it seems dependent on zinc status of the individuals. The objective of this study was to evaluate the relationship between zinc nutritional status and glucose homeostasis in patients with type-2 diabetes.

SUBJECTS/METHODS

Eighty patients with well controlled type-2 diabetes were recruited and clinical, anthropometric and dietary evaluations were performed. One week after, insulin sensitivity and beta cell function were assessed by a modified Frequently Sampled Intravenous Glucose Tolerance Test. Zinc status was assessed by plasma zinc and the size of rapidly Exchangeable Zinc Pool (EZP); zinc intake was also determined. Glucagon concentration was evaluated in a subsample of 36 patients.

RESULTS

Patients presented a normal zinc status although zinc intake was lower than recommended. Overall, no associations were observed between zinc status and glycemic control markers. Nevertheless, positive correlations were observed between EZP and fasting insulin concentration (ρ = 0.393, p = 0.021) and HOMA-IR (ρ = 0.386, p = 0.024) in women, and between plasma zinc concentration and HbA1c (ρ = 0.342, p = 0.020) in men.

CONCLUSIONS

No significant associations were found between zinc status and glycemic control parameters in patients with well-controlled type 2 diabetes and normal zinc status, although low-degree gender-dependent associations were observed. Further research is required to assess the role of zinc status in zinc deficient patients.

ICP-DRC-MS analysis of serum essential and toxic element levels in postmenopausal prediabetic women in relation to glycemic control markers

PURPOSE

Assessment of the influence of prediabetes on serum trace element and electrolyte levels in postmenopausal women.

METHODS

A total of 80 prediabetic and 80 healthy postmenopausal women took part in the present study. Serum was analyzed for glucose, insulin, insulin resistance index (HOMA-IR), total cholesterol (TC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT). Glycated haemoglobin (HbA1c) levels were also assessed. Serum levels of 28 elements were estimated using inductively-coupled plasma mass spectrometry with dynamic reaction cell technology (ICP-DRC-MS).

RESULTS

Prediabetic women were characterized by significantly higher HbA1c, glucose, insulin, HOMA-IR, ALT, and GGT values. Of trace elements, only serum zinc (Zn) levels were significantly lower in prediabetics by 10% (p=0.001) when compared to the controls. Serum Zn levels were characterized by a significant inverse correlation with HbA1c (r=- 0.205; p=0.009), insulin (r=- 0.246; p=0.002), and HOMA-IR (r=- 0.227; p=0.004). Multiple regression analysis demonstrated a significant inverse association between serum Zn (β=-0.169; p=0.031) and Sr (β=-0.192; p=0.012) and HOMA-IR values after adjustment for anthropometric and biochemical parameters (p for a model <0.001). Although serum Zn was significantly associated with HbA1c both in crude and adjusted models, no significant relationship was detected after adjustment for age and anthropometric parameters.

CONCLUSIONS

Prediabetic postmenopausal women are characterized by significantly lower levels of serum Zn concentration, whereas serum Zn and Sr levels were inversely associated with insulin resistance.

Antidiabetic and Antioxidant Effects of Apple Cider Vinegar on Normal and Streptozotocin-Induced Diabetic Rats

Abstract. Diabetes mellitus (DM) is a globally growing health problem and one of the most prevalent endocrine disorders worldwide. Chronic hyperglycemia status favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity. In this study, the beneficial effects of apple cider vinegar (ACV) supplementation on blood glucose level, hepatic and renal toxicity and antioxidant enzyme activities in normal and diabetic rats were investigated. Four groups (8 animals/group) of male Wistar rats were used. The animals were fasted overnight and DM was induced by an intraperitoneal injection of freshly prepared streptozotocin (STZ). Control rats were injected with citrate buffer only. ACV was administrated orally for 4 weeks. Our findings indicated that ACV increased the activity of antioxidant enzymes (superoxide dismutase (p < 0.001), catalase and glutathione peroxidase) as well as thiol concentration (p < 0.05). It also reduced lipid peroxidation levels (TBARS) and the indices of toxicity in liver and kidneys, by significantly decreasing aspartate and lactate transaminase (AST & ALT) activity, total and direct bilirubin (p < 0.001), urea (p < 0.001) and creatinine (p < 0.001) levels. Moreover, the plasma concentration of magnesium, calcium (p < 0.001) and copper increased after ACV administration. Iron levels however decreased. The concentration of vitamin E, an important antioxidant in vivo, was raised. In conclusion, the findings show that ACV possesses significant antihyperglycemic and antioxidant effects in an experimental model of DM, by preventing diabetic complications in liver and kidneys.

The Resulting Variation in Nutrient Intake With the Inclusion of Walnuts in the Diets of Adults at Risk for Type 2 Diabetes: A Randomized, Controlled, Crossover Trial

PURPOSE

We previously demonstrated that including walnuts in the diets of adults at risk for type 2 diabetes mellitus (T2DM) led to improved overall diet quality. This report examines the specific changes in their nutrient intake.

DESIGN

This was a randomized, controlled, modified Latin square parallel design trial with 2 treatment arms. Participants were randomized to walnut intake with, or without, dietary advice to regulate caloric intake. Within each treatment arm, they were further randomized to one of 2 sequence permutations (walnut-included/walnut-excluded or walnut-excluded/walnut-included diet), with a 3-month washout between treatment phases.

SETTING

Community hospital in Lower Naugatuck Valley in Connecticut.

PARTICIPANTS

Cohort of 112 participants (31 men and 81 women) at risk for T2DM.

INTERVENTION

Participants included 56 g (366 kcal) of walnuts in their daily diets for 6 months.

MEASURES

Nutrient intake was assessed using web-based Automated Self-Administered 24-Hour Dietary Assessment.

ANALYSIS

Data were analyzed using generalized linear models.

RESULTS

Walnut inclusion led to increased intake of total fat, calcium, magnesium, thiamin, total saturated fatty acids, and monounsaturated and polyunsaturated fatty acids (379.0 ± 90.3 g vs -136.5 ± 92.7 g, P < .01; 230.7 ± 114.2 mg vs -95.2 ± 117.4 mg, P = .05; 111.0 ± 33.9 mg vs -32.3 ± 34.9 mg, P < .01; 0.28 ± 0.2 mg vs -0.47 ± 0.2 mg, P = .02; 8.6 ± 3.4 g vs -1.1 ± 3.5 g, P =.05; 6.3 ± 3.9 g vs -6.3 ± 4.0 g, P = .03; and 25.4 ± 4.0 vs -6.6 ± 4.2 g, P < .01, respectively). Vitamin C intake decreased (-65.3 ± 55.3 mg vs 98.9 ± 56.8 mg, P = .04). Protein intake increased from baseline with the inclusion of walnuts (20.0 ± 8.8 g, P < .05). Walnut inclusion led to an increase in total calories consumed when caloric intake is not regulated.

CONCLUSION

Including walnuts in the diets of these adults led to increased dietary intake of some nutrients associated with lower risk of developing T2DM and other cardiometabolic risk factors.