Lower serum magnesium concentration is associated with diabetes, insulin resistance, and obesity in South Asian and white Canadian women but not men

How the kidney regulates magnesium: a modelling study

The kidneys are crucial for maintaining Mg2+ homeostasis. Along the proximal tubule and thick ascending limb, Mg2+ is reabsorbed paracellularly, while along the distal convoluted tubule (DCT), Mg2+ is reabsorbed transcellularly via transient receptor potential melastatin 6 (TRPM6). TRPM6 and other renal transporter expressions are regulated by sex hormones. To investigate renal Mg2 handling, we have developed sex-specific computational models of electrolyte transport along rat superficial nephron. Model simulations indicated that along the proximal tubule and thick ascending limb, Mg2+ and Na+ transport occur parallelly, but they are dissociated along the DCT. In addition, our models predicted higher paracellular Mg2+ permeability in females to attain similar cortical thick ascending limb fractional Mg2+ reabsorption in both sexes. Furthermore, DCT fractional Mg2+ reabsorption is higher in females than in males, allowing females to better fine-tune Mg2+ excretion. We validated our models by simulating the administration of three classes of diuretics. The model predicted significantly increased, marginally increased and significantly decreased Mg2+ excretions for loop, thiazide and K-sparing diuretics, respectively, aligning with experimental findings. The models can be used to conduct in silico studies on kidney adaptations to Mg2+ homeostasis alterations during conditions such as pregnancy, diabetes and chronic kidney disease.

Magnesium Status and Dietary Patterns Associated with Glycemic Control in Individuals with Type 2 Diabetes Mellitus

Hypomagnesemia and unhealthy eating patterns are associated with poor glycemic control in individuals with type 2 diabetes mellitus (T2DM). This study aimed to associate magnesium status and dietary patterns with glycemic control in T2DM individuals. This cross-sectional study included 147 individuals with T2DM, aged between 19 and 59 years, of both sexes, residents in Sergipe/Brazil. The BMI, waist circumference, %body fat, plasma magnesium, serum glucose, insulin, %HbA1c, triacylglycerol, total cholesterol, LDL-c, and HDL-c were analyzed. Eating patterns were identified using a 24-h recall method. Logistic regression models were used to verify the association of magnesium status and dietary patterns with markers of glycemic control by adjusting for sex, age, time of T2DM diagnosis, and BMI. A P value < 0.05 was considered significant. Magnesium deficiency increased the chance of elevated %HbA1c by 5.893-fold (P = 0.041). Three main dietary patterns were identified: mixed (MDP), unhealthy (UDP), and healthy (HDP). UDP also increased the chance of elevated %HbA1c levels (P = 0.034). T2DM individuals' who presented magnesium deficiency had a higher chance of elevated %HbA1c levels (8.312-fold) and those in the lowest quartile (Q) of the UDP (Q1: P = 0.007; Q2: P = 0.043) had a lower chance of elevated %HbA1c levels. However, the lower quartiles of the HDP were associated with a greater chance of alterations in the %HbA1c level (Q1: P = 0.050; Q2: P = 0.044). No association was observed between MDP and the variables studied. Magnesium deficiency and UDP were associated with a higher chance of inadequate glycemic control in T2DM individuals.

A Comparison of Magnesium Levels in Obese Versus Normal-Weight Children

Introduction One of the world's most pressing problems right now is childhood obesity. After potassium, magnesium (Mg) is the second most prevalent intracellular cation and the fourth most prevalent mineral in the human body. Numerous symptoms of magnesium insufficiency can include hypocalcemia, hypokalemia, as well as cardiac and neurological symptoms. Additionally, chronically low Mg levels have been associated with a number of chronic diseases such as diabetes, hypertension, coronary heart disease, and osteoporosis. Objectives This study aimed to compare the magnesium (Mg) level between normal-weight and obese children in a tertiary center in Saudi Arabia over the past seven years and evaluate the vitamin D and phosphorus between the two groups as a secondary objective. Methods This is a single-center, case-control study conducted on patients followed up in our center from January 2016 to December 2022. All pediatric patients were between two and 14 years of age. They were divided into two groups: one with children whose body mass index (BMI) was over the 85th percentile and the other with children whose BMI was between the 3rd and 85th percentiles. Results Mean serum Mg levels showed no significant correlation between the obese group (0.82 mg/dl) and the normal-weight group (0.83 mg/dl). However, vitamin D and phosphorus demonstrate a significant difference between the two groups. The obese group revealed a vitamin D of 1.6±0.24 and phosphorus of 4.2±0.46. On the other hand, the normal group had a vitamin D of 44.0±28.2 and phosphorus of 1.5±0.26. Conclusion There was a negative correlation between Mg levels and weight in pediatric patients. However, a positive relationship was observed between the Mg intake and Mg levels. Moreover, sodium, phosphorus, and vitamin D levels showed significant differences.

Auto repair workers exposed to PM2.5 particulate matter in Barranquilla, Colombia: telomere length and hematological parameters

Exposure to 2.5 µm particulate matter (PM_2.5) in automotive repair shops is associated with risks to health. We evaluated the effects of occupational exposure to PM_2.5 among auto repair-shop workers. Blood and urine samples were collected from 110 volunteers from Barranquilla, Colombia: 55 active workers and 55 controls. PM_2.5 concentrations were assessed at each of the sampling sites and chemical content was analyzed by SEM-EDS electron microscopy. The biological samples obtained were peripheral blood (hematological profiling, DNA extraction) and urine (malondialdehyde concentration). Telomere length was assessed by qPCR and polymorphisms in the glutathione transferase genes GSTT1 and GSTM1 by PCR-RFLP, with confirmation by allelic exclusion. White blood cell (WBC), lymphocyte (LYM%) and platelet (PLT) counts and the malondialdehyde concentration were higher (4.10 ± 0.93) in the exposed group compared to the control group (1.56 ± 0.96). TL was shorter (5071 ± 891) in the exposed individuals compared to the control group (6271 ± 805). White blood cell (WBC) and platelet counts were positively associated with exposure. Age and TBARS were correlated with TL in exposed individuals. The GSTT1 gene alleles were not in Hardy-Weinberg (H-W) equilibrium. The GSTM1 gene alleles were in H-W equilibrium and allelic exclusion analysis confirmed the presence of heterozygous GSTM1 genotypes. SEM-EDS analysis showed the presence of potentially toxic elements, including Mg, Al, Fe, Mn, Rh, Zn, and Cu. Auto repair shop workers showed effects that may be associated with exposure to mixtures of pollutants present in PM_2.5. The GSTM1 and GSTT1 genes had independent modulatory effects.

Association of vitamin D and magnesium with insulin sensitivity and their influence on glycemic control

Insulin resistance increases the risk of developing diabetes, and the degree of resistance influences the glycemic control of patients with diabetes. Numerous researchers have focused on improving insulin sensitivity in order to prevent diabetes-related complications and other chronic diseases. Several studies have also linked vitamin D levels to insulin secretion and resistance, given that both vitamin D and its receptor complex play important roles in regulating pancreatic β-cells. It has been suggested that vitamin D supplementation improves vitamin D levels, but further research is needed to confirm this as neither insulin function nor glycemic control improves when vitamin D levels increase. Magnesium is a cofactor for many enzymes. Although the role of magnesium in the management of diabetes has long been evaluated, it has not yet been determined whether magnesium supplements improve insulin function. However, several researchers have found that patients with good glycemic control have high magnesium levels. Magnesium is closely related to vitamin D and is necessary for the transport and activation of vitamin D in humans. Combined supplementation with vitamin D and magnesium improves glycemic control in patients with diabetes.

Magnesium- a Forgotten Element: Phenotypic Variation and Genome Wide Association Study in Turkish Common Bean Germplasm

Magnesium (Mg) is the fourth most abundant element in the human body and plays the role of cofactor for more than 300 enzymatic reactions. In plants, Mg is involved in various key physiological and biochemical processes like growth, development, photophosphorylation, chlorophyll formation, protein synthesis, and resistance to biotic and abiotic stresses. Keeping in view the importance of this element, the present investigation aimed to explore the Mg contents diversity in the seeds of Turkish common bean germplasm and to identify the genomic regions associated with this element. A total of 183 common bean accessions collected from 19 provinces of Turkey were used as plant material. Field experiments were conducted according to an augmented block design during 2018 in two provinces of Turkey, and six commercial cultivars were used as a control group. Analysis of variance depicted that Mg concentration among common bean accessions was statistically significant (p < 0.05) within each environment, however genotype × environment interaction was non-significant. A moderate level (0.60) of heritability was found in this study. Overall mean Mg contents for both environments varied from 0.33 for Nigde-Dermasyon to 1.52 mg kg⁻¹ for Nigde-Derinkuyu landraces, while gross mean Mg contents were 0.92 mg kg⁻¹. At the province level, landraces from Bolu were rich while the landraces from Bitlis were poor in seed Mg contents respectively. The cluster constellation plot divided the studied germplasm into two populations on the basis of their Mg contents. Marker-trait association was performed using a mixed linear model (Q + K) with a total of 7,900 DArTseq markers. A total of six markers present on various chromosomes (two at Pv01, and one marker at each chromosome i.e., Pv03, Pv07, Pv08, Pv11) showed statistically significant association for seed Mg contents. Among these identified markers, the DArT-3367607 marker present on chromosome Pv03 contributed to maximum phenotypic variation (7.5%). Additionally, this marker was found within a narrow region of previously reported markers. We are confident that the results of this study will contribute significantly to start common bean breeding activities using marker assisted selection regarding improved Mg contents.

The association of serum magnesium and chronic kidney disease: a two-sample mendelian randomization study of European descent

BACKGROUND

Previous observational studies focused on the association of serum magnesium (SMg) and chronic kidney disease (CKD), but the conclusion was inconsistent. To investigate the causal relationship of SMg and CKD, we performed a two-sample mendelian randomization (TSMR) analysis using publicly datasets.

METHOD

In mendelian randomization (MR) analysis, we used single nucleotide polymorphisms (SNPs) which had genetic statistical significance with SMg but not associated with kidney function and confounding factors as instrumental variable (IV). To select SNPs, we used publicly database of Genome Wide Association Study (GWAS) and Chronic Kidney Disease Genetics (CKDGen) Confirms. We used inverse-variance weighted (IVW), weighted median, MR-Egger regression, weighted mode, and simple mode approaches in TSMR analysis.

RESULTS

We selected 4 SNPs (rs4072037, rs7965584, rs11144134 and rs448378) as IV. In IVW approach, the result of MR analysis for CKD was OR = 0.55, 95% CI: 0.06, 4.75, P = 0.58; for estimated glomerular filtration rate from creatinine (eGFR)crea was β = -0.06, 95% CI: -1.08, 0.07, P = 0.39; for estimated glomerular filtration rate from cystatin C (eGFR)cys was β = -0.03, 95% CI: -0.43, 0.36, P = 0.86, respectively per SD increase in SMg. When subgroup by diabetes mellitus (DM), the results for DM-eGFRcrea was β = -0.33, 95% CI: -0.85, 0.19, P = 0.21; and for non-DM-eGFRcrea was β = -0.03, 95% CI: -0.16, 0.11, P = 0.71. The results of other four MR approaches were consistent with IVW approach (all P > 0.05).

CONCLUSION

Our TSMR analysis showed that SMg had no causal effect on kidney function and progress CKD in European descent. As for the results about overall population, the verified study is needed in future study.

The effects of subchronic intake of magnesium hydrocarbonate-rich mineral water on body weight and cardiovascular variables in rats with streptozotocin: Induced diabetes

Background/Aim: Optimal intake of magnesium minerals is essential in maintaining the coordinated physiological functions of cells, tissues and organs. The importance of this element is reflected in the fact that it is the fourth most abundant cation in the human body, participating as a cofactor in more than three hundred enzymatic reactions. Its presence is necessary for the proper functioning of a number of vital functions, such as glycaemic control, the work of the heart and the vascular system and it can potentially play a role in the regulation of body weight. Aim of this study was to investigate the effects of subchronic intake of magnesium hydrocarbonate-rich water on changes in body weight, organ weight and cardiovascular variables in rats with streptozotocin-induced diabetes. Methods: Wistar rats (n = 28) were divided into 4 groups: two control groups, on tap water (TW-C, n = 7) and magnesium hydrocarbonate-rich water (MW-C, n = 7); and two experimental groups with streptozotocin-induced diabetes, on tap water (TW-DM, n = 7) and magnesium hydrocarbonate-rich water (MW-DM, n = 7). The values of body weight, organ weight and cardiovascular parameters were compared after 6 weeks between control groups of rats on subchronic treatment with tap water (TW-C) and magnesium hydrocarbonate-rich water (MW-C) and between groups with streptozotocin-induced diabetes on tap water (TW-DM) and with magnesium hydrocarbonate-rich water (MW-DM). Results: By comparing the values of cardiovascular parameters between groups, significant (p < 0.05) positive effects of magnesium hydrocarbonate-rich water were registered on the values of systolic and pulse blood pressure in diabetic rats fed with magnesium hydrocarbonate-rich water (MW-DM) compared to those fed with tap water (TW-DM). In contrast, no significant effect of magnesium hydrocarbonate on changes in body weight and organ weight was observed. Conclusion: Based on the results, the beneficial effects of magnesium hydrocarbonate-rich water in the regulation of blood pressure can be clearly observed. Potential effects on other cardiovascular variables and body weight and organ weight should be further investigated.

Association between magnesium concentrations and prediabetes: a systematic review and meta-analysis

Studies on the association between serum magnesium level and prediabetes yielded inconsistent results. Therefore, the present meta-analysis was designed to examine the association between serum magnesium levels and prediabetes. Online databases including PubMed, Embase, Scopus and Google Scholar were searched up to October, 2020. A total of 10 studies that reported mean and standard deviation (SD) of magnesium levels in prediabetes and healthy control group were identified. Random effects models were used to pool weighted mean differences (WMDs) of serum magnesium levels. Pooled-analysis showed that subjects with prediabetes had significantly lower serum magnesium levels compared with healthy controls (WMD =  - 0.07 mmol/L; 95% CI - 0.09, - 0.05 mmol/L, P < 0.001). A significant heterogeneity observed across included studies (I² = 95.6%, P < 0.001). However, different subgroup analysis did not detect the potential source of observed heterogeneity. Withdrawal of each individual study had no effect on the overall results. The present meta-analysis showed that circulating magnesium levels in people with prediabetes were significantly lower than healthy controls, confirming that magnesium deficiency may play a role in development and progression of prediabetes. Further studies with larger sample size and robust design are warranted to confirm present results.

Whole-blood magnesium and blood lipids are individually and jointly associated with an elevated likelihood of youngsters being overweight or obese: A matched case-control study using the propensity score

OBJECTIVES

Youngsters who are overweight or obese (YOO) have become an important global health concern. Some micronutrients may be modifiable influential factors. This study aimed to investigate the individual and joint association of whole-blood magnesium (WBMg) and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), or high-density lipoprotein cholesterol (HDL-C) in YOO.

METHODS

This is a propensity score matching-based case-control study. YOO was defined depending on age- and sex-specific body mass index z-score, calculated with SAS macros (%group_standard and %WHO2007) from the World Health Organization website. WBMg, blood lipids, and covariates were carefully measured by trained technicians using a whole-blood, five-element, basic analyzer and atomic absorption spectrometer or automatic biochemical analyzer. Locally weighted scattered plot smoothing and multivariable conditional logistic regression models were applied to estimate the associations of WBMg and blood lipids in YOO.

RESULTS

WBMg was positively associated with YOO. The adjusted likelihood of YOO significantly increased by 21% (odds ratio: 1.21; 95% confidence interval [CI], 1.10-1.33) with per-interquartile range elevation of WBMg. Compared with the 1st quartile, adjusted odds ratios among youngsters in the 2^nd, 3^rd, and 4^th quartiles of WBMg were 1.11 (95% CI, 0.92-1.35), 1.29 (95% CI, 1.06-1.57), and 1.47 (95% CI, 1.18-1.83), respectively. Furthermore, the relationship between WBMg and YOO was moderated by lipid profiles. Compared with those having lower (< median) WBMg and TC, TG, LDL-C, or higher (≥ median) HDL-C, youngsters with both higher WBMg and TC, TG, LDL-C, or lower HDL-C had higher YOO odds, which averagely increased by 188%, 250%, 339%, and 369%, respectively.

CONCLUSIONS

WBMg was an independent risk factor of YOO, and the associations were stronger among those with unhealthy blood lipids. Our findings can help to guide clinical and public health policies on the relevance of magnesium nutritional status.

Novel mutations in TRPM6 gene associated with primary hypomagnesemia with secondary hypocalcemia. Case report

BACKGROUND

Primary hypomagnesemia with secondary hypocalcemia (HSH) is a rare genetic disorder. Dysfunctional transient receptor potential melastatin 6 causes impaired intestinal absorption of magnesium, leading to low serum levels accompanied by hypocalcemia. Typical signs at initial manifestation are generalized seizures, tetany, and/or muscle spasms.

CASE REPORT

We present a 5 w/o female manifesting tonic-clonic seizures. Laboratory tests detected severe hypomagnesemia and hypocalcemia. The molecular genetic analysis revealed two novel mutations within the TRPM6 gene c.3308dupC (p.Pro1104Thrfs*28) (p.P1104Tfs*28) and c.3958C>T (p.Gln1302*) (p.Q1302*) and the patient was successfully treated with Mg supplementation.

CONCLUSION

Ion disbalance should be taken into account in the differential diagnosis of infantile seizures. Accurate diagnosis of HSH together with appropriate treatment are crucial to prevent irreversible neurological outcomes.

Associations Between Serum Magnesium Concentrations and Polycystic Ovary Syndrome Status: a Systematic Review and Meta-analysis

Magnesium (Mg) is the second most frequent intracellular cation in humans with a critical role in insulin metabolism and glucoregulation. Women with polycystic ovary syndrome (PCOS) often present with insulin resistance and impaired glucoregulatory status; however, their Mg status remains unclear. Therefore, we aimed to conduct a systematic review and meta-analysis to evaluate serum Mg concentration in women with PCOS and compare it with that of controls without PCOS. Online databases of PubMed, Scopus, Cochrane Library, and ISI Web of Science were searched for studies evaluating the relationship between Mg concentrations and PCOS status until October 2019. Pooled weighted mean differences (WMDs) of serum Mg levels were calculated using random effects models. A total of eight studies (10 arms; n = 2026 women) were included. Pooled effect sizes, expressed as WMD and 95% CI, revealed decreased serum Mg concentrations in women with PCOS compared with controls (- 0.09 (- 0.17, - 0.02) mmol/L; P = 0.01). However, significant heterogeneity was detected across the studies (I ² = 98.0%, P < 0.001). Despite the classification of studies based on baseline BMI classes, we did not detect the potential source of the observed heterogeneity. Subgroup analysis showed that overweight and obese women (BMI ≥ 25 kg/m², 0.07 mmol/L (- 0.14, - 0.01); P = 0.02) with PCOS had lower magnesium concentrations than normal women (BMI < 25 kg/m², - 0.11 (- 0.25, 0.04) mmol/L; P = 0.14) compared with the control group. Serum Mg concentrations appear to be declined in overweight or obese women with PCOS, which may warrant screening and management of Mg status in this clinical population. High-quality studies are needed to elucidate the relationship between Mg concentrations and the development of PCOS.

The effect of magnesium supplementation on anthropometric indices: a systematic review and dose-response meta-analysis of clinical trials

The aim of this study was to determine the effects of Mg supplementation on anthropometric indices consisting of body weight, waist circumference (WC), BMI and body fat percentage. In this systematic review and dose–response meta-analysis, we searched PubMed, Cochrane Library, Scopus, Web of Science and Google Scholar from databases inception up to February 2020 for relevant randomised controlled trials. Quality of evidence was evaluated using the Cochrane Collaboration Tool. All the outcomes of this meta-analysis were pooled using the random effect model. Analysis of dose–response for Mg dosage was carried out using a fractional polynomial model. The systematic review and meta-analysis include twenty-eight randomised clinical trials, comprising 2013 participants. There were no significant changes in anthropometric indices after Mg supplementation in the overall analysis. However, subgroup analysis revealed that Mg supplementation decreases WC in subjects with BMI > 30 kg/m2 (obese) (twelve trials, n 997 participants; weighted mean difference = –2·09 cm, 95 % CI –4·12, –0·07, P = 0·040; I2 = 0 %). Dose–response analysis revealed a non-significant non-linear effect of supplementation dosage on anthropometric indices. The results suggest that Mg supplementation is associated with lower WC only in obese subjects. However, more high-quality studies are needed to clarify the nature of this association.

Synergistic effects of magnesium ions and simvastatin on attenuation of high-fat diet-induced bone loss

Introduction

Magnesium (Mg) has a prophylactic potential against the onset of hyperlipidemia. Similar to statin, Mg is recommended as lipid-lowering medication for hypercholesterolemia and concomitantly exhibits an association with increased bone mass. The combination of statin with Mg ions (Mg²⁺) may be able to alleviate the high-fat diet (HFD)-induced bone loss and reduce the side-effects of statin. This study aimed to explore the feasibility of combined Mg²⁺ with simvastatin (SIM) for treating HFD-induced bone loss in mice and the involving mechanisms.

Materials and methods

C57BL/6 male mice were fed with a HFD or a normal-fat diet (NFD). Mice were intraperitoneally injected SIM and/or orally received water with additional Mg²⁺ until sacrificed. Enzyme-linked immunosorbent assay was performed to measure cytokines and cholesterol in serum and liver lysates. Bone mineral density (BMD) and microarchitecture were assessed by micro-computed tomography (μCT) in different groups. The adipogenesis in palmitate pre-treated HepG2 cells was performed under various treatments.

Results

μCT analysis showed that the trabecular bone mass was significantly lower in the HFD-fed group than that in NFD-fed group since week 8. The cortical thickness in HFD-fed group had a significant decrease at week 24, as compared with NFD-fed group. The combination of Mg²⁺ and SIM significantly attenuated the trabecular bone loss in HFD-fed mice via arresting the osteoclast formation and bone resorption. Besides, such combination also reduced the hepatocytic synthesis of cholesterol and inhibited matrix metallopeptidase 13 (Mmp13) mRNA expression in pre-osteoclasts.

Conclusions

The combination of Mg²⁺ and SIM shows a synergistic effect on attenuating the HFD-induced bone loss. Our current formulation may be a cost-effective alternative treatment to be indicated for obesity-related bone loss.

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High-fat diet-fed mouse has a susceptibility to lower trabecular bone mass as compared with that of normal-fat diet-fed mouse.

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The combination of Mg²⁺ and simvastatin attenuates the trabecular bone loss in high-fat diet-fed mice.

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The combination of Mg²⁺ and simvastatin reduces the hepatocytic synthesis of cholesterol.

Plasma Magnesium Concentrations and Risk of Incident Cancer in Adults with Hypertension: A Nested Case-Control Study

OBJECTIVE

The association between plasma magnesium and risk of incident cancer remains inconclusive in previous studies. We aimed to investigate the prospective relationship of baseline plasma magnesium concentrations with the risk of incident cancer and to examine possible effect modifiers.

METHODS

A nested case-control study with 228 incident cancer cases and 228 matched controls was conducted using data from the China Stroke Primary Prevention Trial (CSPPT), a randomized, double-blind, controlled trial, conducted from May 2008 to August 2013. Study outcomes included incident cancer and its subtypes.

RESULTS

When plasma magnesium concentrations were assessed as quartiles, a significantly higher incident risk of total cancer was found in participants in quartile 1 (<0.76 mmol/L; odds ratio [OR] = 2.70; 95% CI: 1.33-5.49) and quartile 4 (≥0.89 mmol/L; OR = 2.05; 95% CI: 1.12-3.76), compared with those in quartile 3 (0.83 to <0.89 mmol/L). In cancer site-specific analyses, similar trends were found for gastrointestinal cancer, esophageal cancer, gastric cancer, breast cancer, lung cancer, and other cancers. Furthermore, none of the variables, including age, sex, current smoking status, current alcohol intake, BMI, systolic blood pressure, and total cholesterol levels at baseline significantly modified the association between plasma magnesium and cancer risk.

CONCLUSIONS

Both low and high plasma magnesium concentrations were significantly associated with an increased incident risk of cancer, compared with the reference concentrations of 0.83 to <0.89 mmol/L among hypertensive adults.

Cytotoxicity and insulin resistance reversal ability of biofunctional phytosynthesized MgO nanoparticles

The present study investigates the cytotoxicity of hexagonal MgO nanoparticles synthesized via Amaranthus tricolor leaf extract and spherical MgO nanoparticles synthesized via Amaranthus blitum and Andrographis paniculata leaf extracts. In vitro cytotoxicity analysis showed that the hexagonal MgO nanoparticles synthesized from A. tricolor extract demonstrated the least toxicity to both diabetic and non-diabetic cells at 600 μl/ml dosage. The viability of the diabetic cells (3T3-L1) after incubation with varying dosages of MgO nanoparticles was observed to be 55.3%. The viability of normal VERO cells was 86.6% and this stabilized to about 75% even after exposure to MgO nanoparticles dosage of up to 1000 μl/ml. Colorimetric glucose assay revealed that the A. tricolor extract synthesized MgO nanoparticles resulted in ~ 28% insulin resistance reversal. A reduction in the expression of GLUT4 protein at 54 KDa after MgO nanopaSrticles incubation with diabetic cells was observed via western blot analysis to confirm insulin reversal ability. Fluorescence microscopic analysis with propidium iodide and acridine orange dyes showed the release of reactive oxygen species as a possible mechanism of the cytotoxic effect of MgO nanoparticles. It was inferred that the synergistic effect of the phytochemicals and MgO nanoparticles played a significant role in delivering enhanced insulin resistance reversal capability in adipose cells.

The Association between Excess Body Mass and Disturbances in Somatic Mineral Levels

BACKGROUND

Obesity and excess body weight are significant epidemiological issues, not only because they are costly to treat, but also because they are among the leading causes of death worldwide. In 2016, an estimated 40% of the global population was overweight, reflecting the importance of the issue. Obesity is linked to metabolism malfunction and concomitantly with altered mineral levels in the body. In this paper, we review alterations in somatic levels of iron, calcium, magnesium, copper, iodine, chromium, selenium, and zinc in relation to excess body mass.

METHODOLOGY

An electronic literature search was performed using PubMed. Our search covered original English research articles published over the past five years, culminating in 63 papers included for study.

RESULTS

The reviewed papers presented correlation between obesity and hypomagnesemia and hypozincemia. They also indicated that patients with excess body mass present increased body copper levels. Studies have similarly indicated that obesity appears to be associated with lower selenium levels in both blood and urine, which may be correlated with the decline and weakening of defenses against oxidative stress. It has been found that decreased level of chromium is connected with metabolic syndrome. Chromium supplementation influences body mass, but the effect of the supplementation depends on the chemical form of the chromium. It is hypothesized that obesity poses a risk of iodine deficiency and iodine absorption may be disrupted by increased fat intake in obese women. A range of studies have suggested that obesity is correlated with iron deficiency. On the other hand, some reports have indicated that excess body mass may coexist with iron excess. The relation between obesity and body iron level requires further investigation. Calcium signaling seems to be disturbed in obesity, due to the increased production of reactive oxygen species and low level of fast troponin isoform responsible for mediating calcium sensitivity of muscle relaxation. Correlation between excess body mass and calcium levels needs further research.

CONCLUSIONS

Excess body mass is associated with alterations in mineral levels in the body, in particular hypomagnesemia and decreased selenium (Se) and zinc (Zn) levels. Chromium (Cr) deficiency is associated with metabolic syndrome. Obese patients are at risk of iodine deficiency. Excess body mass is associated with elevated levels of copper (Cu). Data on the association between obesity and iron (Fe) levels are contradictory. Obesity coexists with disturbed calcium (Ca) signaling pathways. The association between obesity and body Ca levels has not been investigated in detail.

Magnesium, Oxidative Stress, Inflammation, and Cardiovascular Disease

Hypomagnesemia is commonly observed in heart failure, diabetes mellitus, hypertension, and cardiovascular diseases. Low serum magnesium (Mg) is a predictor for cardiovascular and all-cause mortality and treating Mg deficiency may help prevent cardiovascular disease. In this review, we discuss the possible mechanisms by which Mg deficiency plays detrimental roles in cardiovascular diseases and review the results of clinical trials of Mg supplementation for heart failure, arrhythmias and other cardiovascular diseases.

Hospital-Acquired Dysmagnesemia and In-Hospital Mortality

Background and Objectives: This study aimed to report the incidence of hospital-acquired dysmagnesemia and its association with in-hospital mortality in adult general hospitalized patients. Materials and Methods: We studied 26,020 adult hospitalized patients from 2009 to 2013 who had normal admission serum magnesium levels and at least two serum magnesium measurements during hospitalization. The normal range of serum magnesium was 1.7-2.3 mg/dL. We categorized in-hospital serum magnesium levels based on the occurrence of hospital-acquired hypomagnesemia and/or hypermagnesemia. We assessed the association between hospital-acquired dysmagnesemia and in-hospital mortality using multivariable logistic regression. Results: 28% of patients developed hospital-acquired dysmagnesemia. Fifteen per cent had hospital-acquired hypomagnesemia only, 10% had hospital-acquired hypermagnesemia only, and 3% had both hospital-acquired hypomagnesemia and hypermagnesemia. Compared with patients with persistently normal serum magnesium levels in hospital, those with hospital-acquired hypomagnesemia only (OR 1.77; p < 0.001), hospital-acquired hypermagnesemia only (OR 2.31; p < 0.001), and both hospital-acquired hypomagnesemia and hypermagnesemia (OR 2.14; p < 0.001) were significantly associated with higher in-hospital mortality. Conclusions: Hospital-acquired dysmagnesemia affected approximately one-fourth of hospitalized patients. Hospital-acquired hypomagnesemia and hypermagnesemia were significantly associated with increased in-hospital mortality.

Hubungan Magnesium Serum Dengan Kadar Glukosa Darah Pada Dewasa Overweight Dan Obesitas

Background:Fat deposits in obesity can trigger oxidative stress and systemic inflammation that cause insulin resistance, which increases the risk of diabetes mellitus. Magnesium is a cofactor of various enzymes in glucose metabolism that plays a role in the process of glucose uptake in the muscles and also acts as an anti-inflammatory. Good intake of nutrients can prevent the metabolic diseases.Objectives:to evaluate the correlation among serum magnesium,energy, macro nutrient and magnesium intake with fasting blood glucose levels in overweight and obese adults.Methods: A cross-sectional study was conducted on 93 overweight(BMI ≥ 25-29.9 kg/m2) and obese (BMI ≥30 kg/m2) adults in February to May 2019 in Serengan District, Surakarta City. The measurement of serum magnesium using kalorimetri and fasting blood glucose using hexokinase method. Energy, macro nutritionand magnesium intake was assessed using 2x24 hour food recall. The bivariate analysis was carried out using Pearson correlation with p value of <0.05 followed by multivariable multiple linear regression analysis with 95% CI.Results:There was no significant correlation of energy, macro nutrient and magnesium intake with blood glucose level. There was a significant negative correlation between serum magnesium and fasting blood glucose in overweight and obese adults (p=0.009; r=-0.286; CI95%=-71.321–(-10.480)).Conclusions: Serum magnesium are the factors most associated with blood glucose in overweight and obese adults. Blood glucose will increase along with decreasing level of serum magnesium.ABSTRAKLatar Belakang: Timbunan lemak pada obesitas menjadi pemicu terjadinya stress oksidatif dan inflamasi sitemik penyebab resistensi insulin sehingga risiko terjadinya diabetes mellitus akan meningkat. Magnesium merupakan kofaktor berbagai enzim dalam metabolisme glukosa yang berperan dalam proses ambilan glukosa di otot dan juga sebagai antiinflamasi. Asupan zat gizi yang baik dapat mencegah terjadinya penyakit metabolik.Tujuan: untuk mengevaluasi hubungan magnesium serum, asupan energi, zat gizi makro dan magnesium dengan glukosa darah puasa pada dewasa overweight dan obesitas.Metode: Penelitian crossectional terhadap 93 orang dewasa dengan status gizi lebih atau overweight (IMT ≥ 25-29,9 kg/m2) dan obesitas (IMT ≥30 kg/m2) pada bulan Februari hingga Mei 2019 di Kecamatan Serengan Kota Surakarta. Pemeriksaan magnesium serum dengan metode kalorimetri dan glukosa darah puasa dengan metode heksokinase. Penilaian asupan energi, zat gizi makro dan magnesium dengan food recall 2x24 jam. Analisis bivariat menggunakan korelasi Pearson dengan nilai p < 0,05 dilanjutkan analisis multivariabel regresi linier ganda dengan CI 95%.Hasil: Tidak ada korelasi signifikan asupan energi, zat gizi makro dan magnesium dengan glukosa darah. Adanya korelasi negatif yang signifikan antara kadar serum magnesium dengan glukosa darah puasa pada dewasa overweight dan obesitas (p=0,009; r=-0,286; CI95%=-71,321–(-10,480)).Kesimpulan: Kadar magnesium serum merupakan faktor yang paling berhubungan dengan glukosa darah pada orang dewasa overweight dan obesitas di Kecamatan Serengan Kota Surakarta. Glukosa darah akan meningkat seiring dengan penurunan kadar magnesium serum.

Are Circulating Mg2+ Levels Associated with Glucose Tolerance Profiles and Incident Type 2 Diabetes?

Magnesium (Mg²⁺) is an enzyme co-factor that plays a key role in many biochemical reactions, as well as in glucose metabolism. Clinical evidences have demonstrated that depletion of serum Mg²⁺ increases exponentially with the duration of type 2 diabetes mellitus (T2DM). Diabetes is associated with low Mg²⁺, and hypomagnesemia is associated with insulin resistance, inflammation, and increased risk for cardiovascular disease. In subjects at high risk of inflammation and insulin resistance, supplementation of Mg²⁺ alone ameliorates both phenotypes, slowing the development and progression of hepatic steatosis. We analyze the relationship between serum Mg²⁺ levels and the onset of T2DM in a large cohort of well-characterized adult white individuals participating in the CATAMERI study, who were reexamined after a mean follow-up of 5.6 ± 0.9 years. In our analysis we acquired a significant negative correlation between Mg²⁺ levels, fasting glucose, and 2h-post load glucose in subjects who underwent an OGTT. Moreover, Mg²⁺ levels correlated negatively with fasting insulin levels, and positively with the lipid profile. As for the detrimental effect of lower circulating Mg²⁺ levels, our data revealed a significant reduction of T2DM risk of about 20% for each 1 mg/dL increase of circulating Mg²⁺. The present results are consistent with the theory that Mg²⁺ supplementation could ameliorate insulin sensitivity reducing the risk to develop T2DM.

Effect of Long-term Administration of Oral Magnesium Sulfate and Insulin to Reduce Streptozotocin-Induced Hyperglycemia in Rats: the Role of Akt2 and IRS1 Gene Expressions

The effects of long-term oral administration of magnesium sulfate and insulin on hyperglycemia were investigated using Akt2 and IRS1 gene expression methods in streptozotocin-induced diabetic rats. Fifty rats were randomly divided into five experimental groups: 1, non-diabetic control (NDC); 2, Mg²⁺-treated non-diabetic control (Mg-NDC); 3, chronic diabetic (CD); 4, Mg²⁺-treated chronic diabetic (Mg-CD); and 5, insulin-treated chronic diabetic (Ins-CD). Streptozotocin was used to induce diabetes. The Mg-CD and Mg-NDC groups received 10 g/l of MgSO₄ added to drinking water. The Ins-CD group received 2.5 U/kg of insulin twice a day. Blood glucose level and body weight were measured every week. The intraperitoneal glucose tolerance test (IPGTT) was performed after 16 weeks. MgSO₄ administration improved the blood glucose level and IPGTT. It also increased Akt2 and IRS1 genes as well as protein expression. Insulin lowered the blood glucose level and increased IRS1 gene and protein expression, but did not affect Akt2 gene and protein expression. Glucose reduction after Mg therapy may be mediated, at least partially, via IRS1 and Akt2 genes and protein stimulation. In insulin-treated rats, insulin resistance was not significant due to the absence of Akt2 gene expression.

Influence of LRP5 (rs556442) polymorphism on insulin resistance in healthy Iranian children and adolescents

Background/aim

Genetic aspects play a role in insulin resistance in children. In this study, for the first time, the association of LRP5 (rs556442) polymorphism and insulin resistance in Iranian children and adolescents was investigated.

Materials and methods

The study population comprises children and adolescents aged 9–18 years. Anthropometric and biochemical parameters were assessed. Insulin resistance/sensitivity was determined by the quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment-insulin resistance (HOMA-IR), insulin-to-glucose ratio, McAuley index, revised McAuley index, fasting insulin resistance index (FIRI), and Bennett’s index. LRP5 (rs566442) single nucleotide polymorphism (SNP) was identified using restriction fragment length polymorphism (RFLP). Linear regression analysis was used to determine the association between the LRP5 polymorphism (rs556442) and insulin sensitivity indexes.

Results

Significant differences were found between GG genotype vs. AG/AA genotypes for McAuley index (P = 0.049) and revised McAuley index (P = 0.044) when adjusted for interaction factors (age, sex, and puberty) in regression models. No significant association was found between LRP5 (rs566442) and other insulin resistance indexes. Also, LRP5 (rs566442) did not show a significant impact on biochemical parameters.

Conclusion

This study showed that LRP5 polymorphism (rs556442) was associated with insulin resistance in Iranian children and adolescents.

Influence of endurance and endurance-strength training on mineral status in women with abdominal obesity: a randomized trial

BACKGROUND

Obesity and exercise are associated with disturbances of mineral metabolism, which can lead to physical inefficiency. Our study aimed to compare the influence of endurance and endurance-strength training on mineral status in women with abdominal obesity.

METHODS

Thirty-eight abdominally obese women were randomized into groups A and B and underwent 3 months long training: group A-endurance training and group B-endurance-strength training. Anthropometric and body composition measurements were carried out and the Graded Exercise Test was performed. Blood, urine, and hair samples were collected for mineral content analysis.

RESULTS

Endurance training decreased serum Fe and Zn concentrations as well as hair Zn and Cu content, and increased urine Zn concentration. Endurance-strength training increased serum Mg and Cu concentrations, decreased serum Fe and Zn concentrations, decreased hair Ca and Mg content, and increased urine Ca and Zn concentrations. After training, serum and urine Fe concentration was higher in group A, while urine Ca concentration was higher in group B. A number of correlations was found.

CONCLUSIONS

Both endurance and endurance-strength training have a significant effect on mineral metabolism in obese women; the favorable effects of endurance-strength exercise predominate in iron, magnesium, zinc, and copper balance.

Lower Plasma Magnesium, Measured by Nuclear Magnetic Resonance Spectroscopy, is Associated with Increased Risk of Developing Type 2 Diabetes Mellitus in Women: Results from a Dutch Prospective Cohort Study

Background: Low circulating magnesium (Mg) is associated with an increased risk of developing type 2 diabetes mellitus (T2DM). We aimed to study the performance of a nuclear magnetic resonance (NMR)-based assay that quantifies ionized Mg in EDTA plasma samples and prospectively investigate the association of Mg with the risk of T2DM. Methods: The analytic performance of an NMR-based assay for measuring plasma Mg was evaluated. We studied 5747 subjects free of T2DM at baseline in the Prevention of Renal and Vascular End-stage Disease (PREVEND) study. Results: Passing–Bablok regression analysis, comparing NMR-measured ionized Mg with total Mg measured by the Roche colorimetric assay, produced a correlation of r = 0.90, with a slope of 1.08 (95% CI: 1.00–1.13) and an intercept of 0.02 (95% CI: −0.02–0.08). During a median follow-up period of 11.2 (IQR: 7.7–12.0) years, 289 (5.0%) participants developed T2DM. The association of NMR-measured ionized Mg with T2DM risk was modified by sex (P_interaction = 0.007). In women, we found an inverse association between Mg and the risk of developing T2DM, independent of adjustment for potential confounders (HR: 1.80; 95% CI: 1.20–2.70). In men, we found no association between Mg and the risk of developing T2DM (HR: 0.90; 95%: 0.67–1.21). Conclusion: Lower NMR-measured plasma ionized Mg was independently associated with a higher risk of developing T2DM in women, but not in men.

Magnesium Replacement Improves the Metabolic Profile in Obese and Pre-Diabetic Patients with Mild-to-Moderate Chronic Kidney Disease: A 3-Month, Randomised, Double-Blind, Placebo-Controlled Study

BACKGROUND/AIMS

Magnesium is an essential mineral for many metabolic functions. There is very little information on the effect of magnesium supplementation on metabolic profiles of chronic kidney disease (CKD) patients. The aim of this study was to assess the influence of magnesium supplementation on metabolic profiles of pre-diabetic, obese and mild-to-moderate CKD patients with hypomagnesemia.

METHODS

A total of 128 hypomagnesemic, pre-diabetic and obese patients with an estimated glomerular filtration rate between 90 and 30 ml/min/1.73m2 were enrolled in a randomised, double-blind, placebo-controlled trial. Patients in the magnesium group received 365 mg of oral magnesium (n = 57) once daily for 3 months, while patients in the control group received a placebo (n = 61), also once daily for 3 months. Hypomagnesemia is defined by a serum magnesium level <1.8 mg/dl in males and <1.9 mg/dl in females; obesity is defined as a body mass index ≥30 kg/m2; and pre-diabetes is defined as fasting plasma glucose ≥100 but <126 mg/dl. The primary end point of the study was the change in insulin resistance measured by the homeostastic model assessment for insulin resistance (HOMA-IR).

RESULTS

At the end of follow-up, insulin resistance (-24.5 vs. -8.2%, P = 0.007), HOMA-IR index (-31.9 vs. -3.3%, P < 0.001), hemoglobin A1c (-6.6 vs. -0.16%, P < 0.001), insulin (-29.6 vs. -2.66%, P < 0.001), waist circumference (-4.8 vs. 0.55%, P < 0.001) and uric acid (-0.8 vs. 2.2%, P = 0.004) were significantly decreased in terms of mean changes; albumin (0.91 vs. -2.91%, P = 0.007) and magnesium (0.21 ± 0.18 vs. -0.04 ± 0.05 mg/dl, P < 0.001) were significantly increased in those taking magnesium compared with a placebo. The decrease in metabolic syndrome (-10.5 vs. -4.9%, P = 0.183), obesity (-15.7 vs. -8.2%, P = 0.131), pre-diabetes (-17.5 vs. -9.8%, P = 0.140), and systolic (-5.0 ± 14.8 vs. 0.22 ± 14.9 mm Hg, P = 0.053) and diastolic (-3.07 ± 9.7 vs. 0.07 ± 9.6 mm Hg, P = 0.071) blood pressure did not achieve to a significant level after study.

CONCLUSION

Our data support the argument that magnesium supplementation improves the metabolic status in hypomagnesemic CKD patients with pre-diabetes and obesity.

Magnesium and Human Health: Perspectives and Research Directions

Magnesium is the fourth most abundant cation in the body. It has several functions in the human body including its role as a cofactor for more than 300 enzymatic reactions. Several studies have shown that hypomagnesemia is a common electrolyte derangement in clinical setting especially in patients admitted to intensive care unit where it has been found to be associated with increase mortality and hospital stay. Hypomagnesemia can be caused by a wide range of inherited and acquired diseases. It can also be a side effect of several medications. Many studies have reported that reduced levels of magnesium are associated with a wide range of chronic diseases. Magnesium can play important therapeutic and preventive role in several conditions such as diabetes, osteoporosis, bronchial asthma, preeclampsia, migraine, and cardiovascular diseases. This review is aimed at comprehensively collating the current available published evidence and clinical correlates of magnesium disorders.

Hypomagnesemia and its relation with chronic low-grade inflammation in obesity

Introduction:

The accumulation of visceral fat in obesity is associated with excessive production of proinflammatory adipokines, which contributes to low-grade chronic inflammation state. Moreover, the literature has shown that mineral deficiency, in particular of magnesium, has important role in the pathogenesis of this metabolic disorder with relevant clinical repercussions.

Objective:

To bring updated information about the participation of hypomagnesemia in the manifestation of low-grade chronic inflammation in obese individuals.

Method:

Articles published in PubMed, SciELO, LILACS and ScienceDirect, using the following keywords: "obesity," "magnesium" and "low grade inflammation."

Results:

Scientific evidence suggests that magnesium deficiency favors the manifestation of low-grade chronic inflammation in obese subjects.

Conclusion:

From literature data, it is evident the participation of magnesium through biochemical and metabolic reactions in protecting against this metabolic disorder present in obesity.

Comparison of Serum Magnesium Levels in Overweight and Obese Children and Normal Weight Children

Purpose Abnormalities in serum magnesium levels have been seen in obesity and its related diseases. Our aim is to determine the mean magnesium levels in overweight and obese children as compared to the levels in normal weight controls to study its relationship with obesity and overweight. The study was done at a tertiary care hospital. Methods A case-control study was conducted at the Department of Pediatrics, Combined Military Hospital, Peshawar, over a 12-month period from August 7, 2015 to August 6, 2016. A total of 140 children between 2-14 years of age were included in the study. They were divided into two equal groups of 70 children each. Both of the groups were matched according to their age and sex. Children with a body mass index (BMI) greater than or equal to 85th centile and 95th centile were placed in the overweight and obese category, respectively, and termed as cases while the other 70 children with a BMI greater than or equal to 5th centile but less than 85th centile were categorized as the normal weight group and termed controls. The serum magnesium levels of both case and control groups were calculated. Results The serum magnesium levels were significantly lower in the overweight and obese group (2.08 ± 0.211 mg/dl) as compared to the normal weight group (2.55 ± 0.155 mg/dl, p<0.001). A significantly strong inverse relationship was seen between serum magnesium levels and body mass index. Conclusion Mean serum magnesium levels in overweight and obese children are lower than those in normal weight children. Further studies are required to see the effect of supplementation of diet with this essential micronutrient on the weight of children.

The Central Role of Biometals Maintains Oxidative Balance in the Context of Metabolic and Neurodegenerative Disorders

Traditionally, oxidative stress as a biological aspect is defined as an imbalance between the free radical generation and antioxidant capacity of living systems. The intracellular imbalance of ions, disturbance in membrane dynamics, hypoxic conditions, and dysregulation of gene expression are all molecular pathogenic mechanisms closely associated with oxidative stress and underpin systemic changes in the body. These also include aspects such as chronic immune system activation, the impairment of cellular structure renewal, and alterations in the character of the endocrine secretion of diverse tissues. All of these mentioned features are crucial for the correct function of the various tissue types in the body. In the present review, we summarize current knowledge about the common roots of metabolic and neurodegenerative disorders induced by oxidative stress. We discuss these common roots with regard to the way that (1) the respective metal ions are involved in the maintenance of oxidative balance and (2) the metabolic and signaling disturbances of the most important biometals, such as Mg²⁺, Zn²⁺, Se²⁺, Fe²⁺, or Cu²⁺, can be considered as the central connection point between the pathogenesis of both types of disorders and oxidative stress.

Risk of Deficiency in Multiple Concurrent Micronutrients in Children and Adults in the United States

Certain population sub-groups in the United States are vulnerable to micronutrient malnutrition. Nationally representative data from the National Health and Nutrition Examination Survey (NHANES) describing the biochemical status of vitamins A, B6, B12, C, D, E, folate, and anemia, were aggregated to determine the overall risk of multiple concurrent deficiencies in U.S. children and adults (n = 15,030) aged >9 years. The prevalence of deficiency risk according to socio-demographic, life-stage, dietary supplement use, and dietary adequacy categories was investigated. Thirty-one percent of the U.S. population was at risk of at least one vitamin deficiency or anemia, with 23%, 6.3%, and 1.7% of the U.S. population at risk of deficiency in 1, 2, or 3-5 vitamins or anemia, respectively. A significantly higher deficiency risk was seen in women (37%), non-Hispanic blacks (55%), individuals from low income households (40%), or without a high school diploma (42%), and underweight (42%) or obese individuals (39%). A deficiency risk was most common in women 19-50 years (41%), and pregnant or breastfeeding women (47%). Dietary supplement non-users had the highest risk of any deficiency (40%), compared to users of full-spectrum multivitamin-multimineral supplements (14%) and other dietary supplement users (28%). Individuals consuming an adequate diet based on the Estimated Average Requirement had a lower risk of any deficiency (16%) than those with an inadequate diet (57%). Nearly one-third of the U.S. population is at risk of deficiency in at least one vitamin, or has anemia.

Serum Magnesium Concentrations in the Canadian Population and Associations with Diabetes, Glycemic Regulation, and Insulin Resistance

Total serum magnesium (Mg) concentration (SMC) is commonly used to assess Mg status. This study reports current SMCs of Canadians and their associations with demographic factors, diabetes, and measures of glycemic control and insulin resistance using results from the Canadian Health Measures Survey cycle 3 (2012-2013). Associations were examined in adults aged 20-79 years using linear mixed models. Mean SMCs and percentile distributions for 11 sex-age groups between 3 and 79 years (n = 5561) are reported. SMCs were normally distributed and differences (p < 0.05) among sex and age groups were small. Between 9.5% and 16.6% of adult sex-age groups had a SMC below the lower cut-off of a population-based reference interval (0.75-0.955 mmol·L^-1) established in the United States population as part of the NHANES I conducted in 1971-1974. Having diabetes was associated with 0.04 to 0.07 mmol·L^-1 lower SMC compared to not having diabetes in the various models. Body mass index, glycated hemoglobin, serum glucose and insulin concentrations, and homeostatic model assessment of insulin resistance were negatively associated with SMC. This is the first study to report SMCs in a nationally representative sample of the Canadian population. A substantial proportion of Canadians are hypomagnesaemic in relation to a population-based reference interval, and SMC was negatively associated with diabetes and indices of glycemic control and insulin resistance.

Role of Magnesium in Oxidative Stress in Individuals with Obesity

Adipose tissue is considered an endocrine organ that promotes excessive production of reactive oxygen species when in excess, thus contributing to lipid peroxidation. Magnesium deficiency contributes to the development of oxidative stress in obese individuals, as this mineral plays a role as an antioxidant, participates as a cofactor of several enzymes, maintains cell membrane stability and mitigates the effects of oxidative stress. The objective of this review is to bring together updated information on the participation of magnesium in the oxidative stress present in obesity. We conducted a search of articles published in the PubMed, SciELO and LILACS databases, using the keywords 'magnesium', 'oxidative stress', 'malondialdehyde', 'superoxide dismutase', 'glutathione peroxidase', 'reactive oxygen species', 'inflammation' and 'obesity'. The studies show that obese subjects have low serum concentrations of magnesium, as well as high concentrations of oxidative stress marker in these individuals. Furthermore, it is evident that the adequate intake of magnesium contributes to its appropriate homeostasis in the body. Thus, this review of current research can help define the need for intervention with supplementation of this mineral for the prevention and treatment of disorders associated with this chronic disease.

Obesity and hypomagnesemia

BACKGROUND

Whether low serum magnesium is an epiphenomenon related with obesity or, whether obesity per se is cause of hypomagnesemia, remains to be clarified.

OBJECTIVE

To examine the relationship between body weight status and hypomagnesemia in apparently healthy subjects.

METHODS

A total of 681 healthy individuals aged 30 to 65years were enrolled in A cross-sectional study. Extreme exercise, chronic diarrhea, alcohol intake, use of diuretics, smoking, oral magnesium supplementation, diabetes, malnutrition, hypertension, liver disease, thyroid disorders, and renal damage were exclusion criteria. Based in the Body Mass Index (BMI), body weight status was defined as follows: normal weight (BMI <25kg/m²); overweight (BMI ≥25<30 BMIkg/m²); and obesity (BMI ≥30kg/m²). Hypomagnesemia was defined by serum magnesium concentration ≤0.74mmol/L. A multiple logistic regression analysis was used to compute the odds ratio (OR) between body weight status (independent variables) and hypomagnesemia (dependent variable).

RESULTS

The multivariate logistic regression analysis showed that dietary magnesium intake (OR 2.11; 95%CI 1.4-5.7) but no obesity (OR 1.53; 95%CI 0.9-2.5), overweight (OR 1.40; 95%CI 0.8-2.4), and normal weight (OR 0.78; 95%CI 0.6-2.09) were associated with hypomagnesemia. A subsequent logistic regression analysis adjusted by body mass index, waist circumference, total body fat, systolic and diastolic blood pressure, and triglycerides levels showed that hyperglycemia (2.19; 95%CI 1.1-7.0) and dietary magnesium intake (2.21; 95%CI 1.1-8.9) remained associated with hypomagnesemia.

CONCLUSIONS

Our results show that body weight status is not associated with hypomagnesemia and that, irrespective of obesity, hyperglycemia is cause of hypomagnesemia in non-diabetic individuals.

Moderately Low Magnesium Intake Impairs Growth of Lean Body Mass in Obese-Prone and Obese-Resistant Rats Fed a High-Energy Diet

The physical and biochemical changes resulting from moderately low magnesium (Mg) intake are not fully understood. Obesity and associated co-morbidities affect Mg metabolism and may exacerbate Mg deficiency and physiological effects. Male rats selectively bred for diet-induced obesity (OP, obese-prone) or resistance (OR, obese-resistant) were fed a high-fat, high-energy diet containing moderately low (LMg, 0.116 ± 0.001 g/kg) or normal (NMg, 0.516 ± 0.007 g/kg) Mg for 13 weeks. The growth, body composition, mineral homeostasis, bone development, and glucose metabolism of the rats were examined. OP and OR rats showed differences (p < 0.05) in many physical and biochemical measures regardless of diet. OP and OR rats fed the LMg diet had decreased body weight, lean body mass, decreased femoral size (width, weight, and volume), and serum Mg and potassium concentrations compared to rats fed the NMg diet. The LMg diet increased serum calcium (Ca) concentration in both rat strains with a concomitant decrease in serum parathyroid hormone concentration only in the OR strain. In the femur, Mg concentration was reduced, whereas concentrations of Ca and sodium were increased in both strains fed the LMg diet. Plasma glucose and insulin concentrations in an oral glucose tolerance test were similar in rats fed the LMg or NMg diets. These results show that a moderately low Mg diet impairs the growth of lean body mass and alters femoral geometry and mineral metabolism in OP and OR rats fed a high-energy diet.

Serum Magnesium Concentration Is Inversely Associated with Albuminuria and Retinopathy among Patients with Diabetes

Aim. To investigate the association between serum magnesium levels and microvascular complications among patients with diabetes. Methods. Patients with diabetes were recruited between April 2012 and January 2015. All patients received an assay of serum magnesium concentration, were screened for 24 h albumin excretion rate, and underwent nonmydriatic fundus photography. Albuminuria and retinopathy were defined accordingly. A total of 3,100 patients with normal serum magnesium levels were included in this study. Results. Patients with albuminuria and/or retinopathy had lower levels of serum magnesium than patients without these complications (P < 0.001). The prevalence of isolated albuminuria, isolated retinopathy, and combined albuminuria and retinopathy decreased as the concentration of serum magnesium increased. Multiple logistic regression analysis indicated that the odds ratio for isolated albuminuria, isolated retinopathy, and concomitant albuminuria and retinopathy decreased by approximately 20% for every 0.1 mmol/L increase in serum magnesium concentration. Conclusion. Serum magnesium levels were negatively associated with the risk of diabetic microvascular complications among patients with serum magnesium levels within the normal range.