Magnesium metabolism in health and disease

Neurological manifestations of hypermagnesemia: a narrative review

Hypermagnesemia is a rare but potentially fatal electrolyte disorder. High serum magnesium levels have been associated with the development of neurological manifestations such as dysautonomia, muscle weakness, respiratory failure, and altered level of consciousness from drowsiness to coma. Although rare, some subjects, such as those with chronic renal failure and those taking magnesium supplements or medications, are at risk of developing this condition. Recognizing this electrolyte alteration promptly allows for an immediate initiation of a therapeutic strategy that is often resolutive when addressed in time. This paper aims to review the neurological complications associated with hypermagnesemia, their pathophysiology, and management.

Association between Serum Magnesium Levels and Risk of Dyslipidemia: A Cross-Sectional Study from the China Health and Nutrition Survey

A growing number of observational studies have been carried out on the relationship between serum magnesium and risk of dyslipidemia, but their results were conflicting. This study aimed to investigate the association between serum magnesium levels and risk of dyslipidemia in Chinese adult residents. We used data from the China Health and Nutrition Survey (CHNS) in the wave of 2009 to conduct a cross-sectional study. A total of 8,457 participants (47.2% male) with a mean age of 50.5 years were assessed and divided into 4 groups based on quartiles of serum magnesium levels. We found that higher quartiles of serum magnesium were associated with increased prevalence of dyslipidemia. After adjustment for confounders, the results of logistic regression analyses indicated that there was an increased trend in dyslipidemia risk as quartiles of serum magnesium increased. The restricted cubic spline model revealed a nonlinear relationship between serum magnesium levels and dyslipidemia. In subgroup analyses, the positive relationship between serum magnesium levels and dyslipidemia was more significant in females than in males. Our study suggested that serum magnesium levels were positively associated with risk of dyslipidemia in Chinese adult population. Further research is needed to provide a deep understanding of the underlying mechanism of magnesium on lipid metabolism.

Serum Magnesium Levels in Patients with Chronic Kidney Disease: Is There a Relationship with Inflammation Status?

BACKGROUND

Magnesium (Mg2+) is a fundamental mineral that maintains cellular function, and low levels may be linked to inflammation in patients with chronic kidney disease (CKD). This cross-sectional study evaluated the correlation between serum Mg2+ levels and the inflammatory status in patients undergoing dialysis.

METHODS

Two hundred patients with CKD [150 undergoing hemodialysis (HD), 50 (18) years; BMI 24 (4.8) kg/m²; and 50 patients on peritoneal dialysis (PD), 54 (17.7) years; BMI, 27.5 (7.3) kg/m²] were included. Serum Mg2+ levels were evaluated using a colourimetric test and commercial kit. Inflammatory markers were assessed by ELISA and multiplex bead-based assay. Lipid peroxidation was evaluated using thiobarbituric acid-reactive substances.

RESULTS

The median serum Mg2+ levels were 2.3 (0.5) mg/dL, and 21% of patients presented Mg2+ deficiency (< 2.07 mg/dL or 0.85 mmol/L). We found no difference in Mg2+ serum levels between the two groups. A significant negative correlation was observed between serum Mg2+ levels and plasma hs-CRP (r =-0.17, p = 0.01), IL-8 (r =-0.35, p = 0.01), and MCP-1 (r =-0.31, p = 0.03) levels.

CONCLUSION

Mg2+ serum levels were negatively correlated with inflammatory status in patients with CKD on dialysis.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

The Association Between Serum Magnesium Levels and Gestational Diabetes Mellitus: a Systematic Review and Meta-Analysis

Observational studies suggest that the potential role of magnesium remains controversial in gestational diabetes mellitus (GDM). This meta-analysis aims to consolidate the available information from observational studies that have focused on the relationship between magnesium levels and GDM. A systematic and comprehensive literature search was conducted in PubMed, Embase, Web of Science, CNKI, and Wanfang databases. Data were extracted independently by two investigators. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used to summarize the circulating magnesium levels (CI). This meta-analysis included a total of 17 studies involving 2858 participants including 1404 GDM cases and 1454 healthy controls, which showed that magnesium levels were significantly lower in GDM compared to healthy controls (SMD: - 0.35; 95% CI: - 0.62, - 0.07, P = 0.013). Likewise, the same phenomenon was observed in the third trimester (SMD =  - 1.07; 95% CI: - 1.84 to - 0.29, P = 0.007). Other subgroup analyses revealed that this trend of decreasing magnesium concentration was only observed in Europeans (SMD =  - 0.64; 95% CI: - 0.90, - 0.38, P < 0.0001). This meta-analysis revealed that serum magnesium levels were lower in patients with GDM than in healthy pregnant women, and this discrepancy was most pronounced in European populations and during the third trimester. Nevertheless, current evidence suggests that circulating magnesium deficiency is associated with gestational diabetes; the challenge for the future is to further elucidate the possible benefits of preventing gestational diabetes through magnesium supplementation.

Acute Oncologic Complications: Clinical-Therapeutic Management in Critical Care and Emergency Departments

Introduction. It is now known that cancer is a major public health problem; on the other hand, it is less known, or rather, often underestimated, that a significant percentage of cancer patients will experience a cancer-related emergency. These conditions, depending on the severity, may require treatment in intensive care or in the emergency departments. In addition, it is not uncommon for a tumor pathology to manifest itself directly, in the first instance, with a related emergency. The emergency unit proves to be a fundamental and central unit in the management of cancer patients. Many cancer cases are diagnosed in the first instance as a result of symptoms that lead the patient's admittance into the emergency room. Materials and Methods. This narrative review aims to analyze the impact of acute oncological cases in the emergency setting and the role of the emergency physician in their management. A search was conducted over the period January 1981-April 2023 using the main scientific platforms, including PubMed, Scopus, Medline, Embase and Google scholar, and 156 papers were analyzed. Results. To probe into the main oncological emergencies and their management in increasingly overcrowded emergency departments, we analyzed the following acute pathologies: neurological emergencies, metabolic and endocrinological emergencies, vascular emergencies, malignant effusions, neutropenic fever and anemia. Discussion/Conclusions. Our analysis found that a redefinition of the emergency department connected with the treatment of oncology patients is necessary, considering not only the treatment of the oncological disease in the strict sense, but also the comorbidities, the oncological emergencies and the palliative care setting. The need to redesign an emergency department that is able to manage acute oncological cases and end of life appears clear, especially when this turns out to be related to severe effects that cannot be managed at home with integrated home care. In conclusion, a redefinition of the paradigm appears mandatory, such as the integration between the various specialists belonging to oncological medicine and the emergency department. Therefore, our work aims to provide what can be a handbook to detect, diagnose and treat oncological emergencies, hoping for patient management in a multidisciplinary perspective, which could also lead to the regular presence of an oncologist in the emergency room.

Development and validation of a simple microwave-assisted digestion sample preparation technique for the estimation of aluminium and magnesium in a few pharmaceutical dosage forms by an inductively coupled-mass spectrometer (ICP-MS)

Rationale: A simple, sensitive, reliable, validated, inductively coupled plasma mass spectrometric method for the determination of aluminium and magnesium using a simple common microwave-assisted digestion sample preparation technique for a few commonly used formulations was developed and validated according to International Conference on Harmonization Q3D and the United States Pharmacopeia general chapter <232> and <233>. The following pharmaceutical dosage forms were considered for estimation of aluminium and magnesium: Alumina, magnesia simethicone oral suspension, Alumina, magnesia simethicone chewable tablets, alumina and magnesia oral suspension, alumina and magnesium carbonate oral suspension. Methods: The methodology included optimizing a common microwave assisted digestion method, selecting the isotopes, choosing the measurement technique, and designating internal standards. The finalized microwave assisted procedure was a two-step program where in the first step the samples were ramped for 10 min to a temperature of 180 °C and hold for 5 min followed by ramping for 10 min to a temperature of 200 °C and hold for 10 min. Magnesium (24Mg) and aluminium (27Al) isotopes were finalized, internal standard assigned for both the isotopes was yttrium (89Y) with Helium (kinetic energy discrimination-KED) as the measuring mode. System suitability was run before initiating analysis to ensure that system performance was consistent. Results: Analytical validation parameters like specificity, linearity (from 25% to 200% of sample concentration), the detection limit and the limit of quantification were established. For all these dosage forms, the method's precision was demonstrated by analyzing the percentage relative standard deviation for six injections. Accuracy was established from 50% to 150% of instrument working concentration (J-levels) for aluminium and magnesium for all the formulations and was found to be within the range of 90-120%. Conclusion: This common analysis method, along with the common microwave-digestion technique applies to numerous types of matrices for a finished dosage form with aluminium and magnesium.

Gene-nutrient interactions that impact magnesium homeostasis increase risk for neural tube defects in mice exposed to dolutegravir

In 2018, data from a surveillance study in Botswana evaluating adverse birth outcomes raised concerns that women on antiretroviral therapy (ART) containing dolutegravir (DTG) may be at increased risk for neural tube defects (NTDs). The mechanism of action for DTG involves chelation of Mg2+ ions in the active site of the viral integrase. Plasma Mg2+ homeostasis is maintained primarily through dietary intake and reabsorption in the kidneys. Inadequate dietary Mg2+ intake over several months results in slow depletion of plasma Mg2+ and chronic latent hypomagnesemia, a condition prevalent in women of reproductive age worldwide. Mg2+ is critical for normal embryonic development and neural tube closure. We hypothesized that DTG therapy might slowly deplete plasma Mg2+ and reduce the amount available to the embryo, and that mice with pre-existing hypomagnesemia due to genetic variation and/or dietary Mg2+ insufficiency at the time of conception and initiation of DTG treatment would be at increased risk for NTDs. We used two different approaches to test our hypothesis: 1) we selected mouse strains that had inherently different basal plasma Mg2+ levels and 2) placed mice on diets with different concentrations of Mg2+. Plasma and urine Mg2+ were determined prior to timed mating. Pregnant mice were treated daily with vehicle or DTG beginning on the day of conception and embryos examined for NTDs on gestational day 9.5. Plasma DTG was measured for pharmacokinetic analysis. Our results demonstrate that hypomagnesemia prior to conception, due to genetic variation and/or insufficient dietary Mg2+ intake, increases the risk for NTDs in mice exposed to DTG. We also analyzed whole-exome sequencing data from inbred mouse strains and identified 9 predicted deleterious missense variants in Fam111a that were unique to the LM/Bc strain. Human FAM111A variants are associated with hypomagnesemia and renal Mg2+ wasting. The LM/Bc strain exhibits this same phenotype and was the strain most susceptible to DTG-NTDs. Our results suggest that monitoring plasma Mg2+ levels in patients on ART regimens that include DTG, identifying other risk factors that impact Mg2+ homeostasis, and correcting deficiencies in this micronutrient might provide an effective strategy for mitigating NTD risk.

Hypomagnesemia in Patients With Cancer: The Forgotten Ion

Magnesium is crucial for various cellular and enzymatic processes, yet it often is overlooked or underappreciated. Hypomagnesemia, a deficiency of magnesium in the blood, is a frequent problem in cancer patients and can lead to severe symptoms and morbidity. In this review, we provide an in-depth analysis of the physiology and regulation of magnesium, and signs and symptoms of hypomagnesemia in cancer patients. We also examine the causes and mechanisms of magnesium imbalances in cancer patients, specifically focusing on cancer-specific therapies that can lead to hypomagnesemia. Finally, we provide updates on the management of hypomagnesemia, including oral and parenteral supplementation, as well as the role of drugs in cases that are resistant to treatment. This review aims to raise awareness among health care providers caring for cancer patients about the significance of monitoring magnesium levels in cancer patients and function as a guide. Future clinical studies should focus on magnesium monitoring, its impact on cancer progression, and its potential for preventing acute kidney injury.

Characterization of Hypomagnesemia in Alcoholic Hepatitis Patients and Its Association with Liver Injury and Severity Markers

INTRODUCTION

Hypomagnesemia has been documented in alcohol-associated liver disease (ALD). This study aims to characterize hypomagnesemia in alcoholic hepatitis (AH) patients and identify its response with liver injury and severity markers.

MATERIALS AND METHODS

A total of 49 male and female AH patients with an age range of 27-66 years were enrolled in this study. Patients were grouped by MELD: MiAH (mild AH < 12 [n = 5]), MoAH (12 ≤ moderate AH ≤ 19 [n = 13]), and SAH (severe AH ≥ 20 [n = 31]). Patients were also evaluated by MELD grouping as non-severe (MELD ≤ 19 [n = 18]) and severe (MELD ≥ 20 [n = 31]). Data were collected on demographics (Age; BMI), drinking history (AUDIT; LTDH), liver injury (ALT; AST), and liver severity (Maddrey's DF; MELD; AST:ALT). Serum magnesium (SMg) levels were tested as SOC lab (normal ≥ 0.85 ≤ 1.10 mmol/L).

RESULTS

SMg was deficient in each group; the lowest in the MoAH patients. The true positivity of SMg values were at a good performance level when compared between severe and non-severe AH patients (AUROC: 0.695, p = 0.034). We found that the SMg level < 0.78 mmol/L could predict severe AH (sensitivity = 0.100 and 1-specificity = 0.000) at this true positivity, and subsequently analyzed patients with SMg < 0.78 mmol/L (Gr.4) and ≥0.78 mmol/L (Gr.5). Between Gr.4 and Gr.5, there were clinically as well as statistically significant differences in disease severity as defined by MELD, Maddrey's DF, and ABIC scores.

CONCLUSIONS

This study demonstrates the utility of SMg levels to identify AH patients who may have progressed to severe status. The extent of magnesium response in AH patients also corresponded significantly with the prognosis of liver disease. Physicians suspecting AH in patients with recent heavy drinking may use SMg as an indicator to guide further testing, referrals, or treatment.

Magnesium reabsorption in the kidney

Mg²⁺ is essential for many cellular and physiological processes, including muscle contraction, neuronal activity, and metabolism. Consequently, the blood Mg²⁺ concentration is tightly regulated by balanced intestinal Mg²⁺ absorption, renal Mg²⁺ excretion, and Mg²⁺ storage in bone and soft tissues. In recent years, the development of novel transgenic animal models and identification of Mendelian disorders has advanced our current insight in the molecular mechanisms of Mg²⁺ reabsorption in the kidney. In the proximal tubule, Mg²⁺ reabsorption is dependent on paracellular permeability by claudin-2/12. In the thick ascending limb of Henle's loop, the claudin-16/19 complex provides a cation-selective pore for paracellular Mg²⁺ reabsorption. The paracellular Mg²⁺ reabsorption in this segment is regulated by the Ca²⁺-sensing receptor, parathyroid hormone, and mechanistic target of rapamycin (mTOR) signaling. In the distal convoluted tubule, the fine tuning of Mg²⁺ reabsorption takes place by transcellular Mg²⁺ reabsorption via transient receptor potential melastatin-like types 6 and 7 (TRPM6/TRPM7) divalent cation channels. Activity of TRPM6/TRPM7 is dependent on hormonal regulation, metabolic activity, and interacting proteins. Basolateral Mg²⁺ extrusion is still poorly understood but is probably dependent on the Na⁺ gradient. Cyclin M2 and SLC41A3 are the main candidates to act as Na⁺/Mg²⁺ exchangers. Consequently, disturbances of basolateral Na⁺/K⁺ transport indirectly result in impaired renal Mg²⁺ reabsorption in the distal convoluted tubule. Altogether, this review aims to provide an overview of the molecular mechanisms of Mg²⁺ reabsorption in the kidney, specifically focusing on transgenic mouse models and human hereditary diseases.

Magnesium Administration in Chronic Kidney Disease

Awareness of the clinical relevance of magnesium in medicine has increased over the last years, especially for people with chronic kidney disease (CKD), due to magnesium's role in vascular calcification and mineral metabolism. The inverse association between serum magnesium and clinically relevant, adverse outcomes is well-established in people with CKD. Subsequent intervention studies have focused on the effect of magnesium administration, mainly in relation to cardiovascular diseases, mineral bone metabolism, and other metabolic parameters. The most commonly used routes of magnesium administration are orally and by increasing dialysate magnesium. Several oral magnesium formulations are available and the daily dosage of elemental magnesium varies highly between studies, causing considerable heterogeneity. Although data are still limited, several clinical studies demonstrated that magnesium administration could improve parameters of vascular function and calcification and mineral metabolism in people with CKD. Current clinical research has shown that magnesium administration in people with CKD is safe, without concerns for severe hypermagnesemia or negative interference with bone metabolism. It should be noted that there are several ongoing magnesium intervention studies that will contribute to the increasing knowledge on the potential of magnesium administration in people with CKD.

Association of Hypomagnesemia and Liver Injury, Role of Gut-Barrier Dysfunction and Inflammation: Efficacy of Abstinence, and 2-Week Medical Management in Alcohol Use Disorder Patients

(1) We investigated the involvement of serum magnesium level in early alcoholic liver disease (ALD), gut barrier dysfunction, and inflammation in alcohol use disorder (AUD) patients; and lastly, the efficacy of 2-week abstinence and medical management to alleviate hypomagnesemia. (2) Forty-eight heavy drinking AUD patients (34 males (M)/14 females (F)) participated in this study. Patients were grouped by serum alanine aminotransferase (ALT) level (a marker of liver injury) as group 1 (Group 1 (Gr.1); ALT ≤ 40 U/L, 7M/8F, without any indication of early-stage ALD) and group 2 (Group 2 (Gr.2); ALT > 40 U/L, 27M/6F or early-stage ALD). These patients were sub-divided within each group into patients with normal magnesium (0.85 and more mmol/L) and deficient magnesium (less than 0.85 mmol/L) levels. All participants were assessed at baseline (BL) and received standard medical management for 2 weeks with reassessment at the treatment end (2w). (3) Female participants of this study showed a significantly lower baseline level of magnesium than their male counterparts. Gr.2 patients showed a greater propensity in the necrotic type of liver cell death, who reported higher chronic and recent heavy drinking. Magnesium level improved to the normal range in Gr.2 post-treatment, especially in the hypomagnesemia sub-group (0.77 ± 0.06 mmol/L (BL) vs. 0.85 ± 0.05 mmol/L (2w), p = 0.02). In Gr.2, both apoptotic (K18M30) and necrotic (K18M65) responses were significantly and independently associated with inflammasome activity comprising of LBP (Lipopolysaccharide binding-protein) and TNFα (Tumor necrosis factor -α), along with serum magnesium. (4) In AUD patients with liver injury, 2-week medical management seems to improve magnesium to a normal level. This group exhibited inflammatory activity (LBP and TNFα) contributing to clinically significant hypomagnesemia. In this group, the level of magnesium, along with the unique inflammatory activity, seems to significantly predict apoptotic and necrotic types of hepatocyte death.

Biological and Physico-Chemical Properties of Composite Layers Based on Magnesium-Doped Hydroxyapatite in Chitosan Matrix

In the present study, we report the development and characterization of composite layers (by spin coating) based on magnesium-doped hydroxyapatite in a chitosan matrix, (Ca_10-xMg_x(PO₄)₆(OH)₂; x_Mg = 0, 0.08 and 0.3; HApCh, 8MgHApCh and 30MgHApCh). The MgHApCh composite layers were investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) techniques. The in vitro biological evaluation included the assessment of their cytotoxicity on MG63 osteoblast-like cells and antifungal activity against Candida albicans ATCC 10231 fungal cell lines. The results of the physico-chemical characterization highlighted the obtaining of uniform and homogeneous composite layers. In addition, the biological assays demonstrated that the increase in the magnesium concentration in the samples enhanced the antifungal effect but also decreased their cytocompatibility. However, for certain optimal magnesium ion concentrations, the composite layers presented both excellent biocompatibility and antifungal properties, suggesting their promising potential for biomedical applications in both implantology and dentistry.

Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease, often punctuated by recurrent flare-ups or exacerbations. Magnesium sulfate, having a bronchodilatory effect, may have a potential role as an adjunct treatment in COPD exacerbations. However, comprehensive evidence of its effects is required to facilitate clinical decision-making.

OBJECTIVES

To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) trials portal, EU Clinical Trials Register and Iranian Registry of Clinical Trials. We also searched the proceedings of major respiratory conferences and reference lists of included studies up to 2 August 2021.

SELECTION CRITERIA

We included single- or double-blind parallel-group randomised controlled trials (RCTs) assessing magnesium sulfate in adults with COPD exacerbations. We excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. The primary outcomes were: hospital admissions (from the emergency room); need for non-invasive ventilation (NIV), assisted ventilation or admission to intensive-care unit (ICU); and serious adverse events. Secondary outcomes were: length of hospital stay, mortality, adverse events, dyspnoea score, lung function and blood gas measurements. We assessed confidence in the evidence using GRADE methodology. For missing data, we contacted the study investigators.

MAIN RESULTS

We identified 11 RCTs (10 double-blind and 1 single-blind) with a total 762 participants. The mean age of participants ranged from 62 to 76 years. Trials were single- or two-centre trials conducted in Iran, New Zealand, Nepal, Turkey, the UK, Tunisia and the USA between 2004 and 2018. We judged studies to be at low or unclear risk of bias for most of the domains. Three studies were at high risk for blinding and other biases.  Intravenous magnesium sulfate versus placebo Seven studies (24 to 77 participants) were included. Fewer people may require hospital admission with magnesium infusion compared to placebo (odds ratio (OR) 0.45, 95% CI 0.23 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) = 7; 3 studies, 170 participants; low-certainty evidence). Intravenous magnesium may result in little to no difference in the requirement for non-invasive ventilation (OR 0.74, 95% CI 0.31 to 1.75; very low-certainty evidence). There were no reported cases of endotracheal intubation (2 studies, 107 participants) or serious adverse events (1 study, 77 participants) in either group. Included studies did not report intensive care unit (ICU) admission or deaths. Magnesium infusion may reduce the length of hospital stay by a mean difference (MD) of 2.7 days (95% CI 4.73 days to 0.66 days; 2 studies, 54 participants; low-certainty evidence) and improve dyspnoea score by a standardised mean difference of -1.40 (95% CI -1.83 to -0.96; 2 studies, 101 participants; low-certainty evidence). We were uncertain about the effect of magnesium infusion on improving lung function or oxygen saturation. For all adverse events, the Peto OR was 0.14 (95% CI 0.02 to 1.00; 102 participants); however, the event rate was too low to reach a robust conclusion.  Nebulised magnesium sulfate versus placebo Three studies (20 to 172 participants) were included. Magnesium inhalation may have little to no impact on hospital admission (OR 0.77, 95% CI 0.21 to 2.82; very low-certainty evidence) or need for ventilatory support (NIV or mechanical ventilation) (OR 0.33, 95% CI 0.01 to 8.20; very low-certainty evidence). It may result in fewer ICU admissions compared to placebo (OR 0.39, 95% CI 0.15 to 1.00; very low-certainty evidence) and improvement in dyspnoea (MD -14.37, 95% CI -26.00 to -2.74; 1 study, 20 participants; very low-certainty evidence). There were no serious adverse events reported in either group. There was one reported death in the placebo arm in one trial, but the number of participants was too small for a conclusion. There was limited evidence about the effect of magnesium inhalation on length of hospital stay, lung function outcomes or oxygen saturation. Included studies did not report adverse events.  Magnesium sulfate versus ipratropium bromide  A single study with 124 participants assessed nebulised magnesium sulfate plus intravenous magnesium infusion versus nebulised ipratropium plus intravenous normal saline. There was little to no difference between these groups in terms of hospital admission (OR 1.62, 95% CI 0.78 to 3.37), endotracheal intubation (OR 1.69, 95% CI 0.61 to 4.71) and length of hospital stay (MD 1.10 days, 95% CI -0.22 to 2.42), all with very low-certainty evidence. There were no data available for non-invasive ventilation, ICU admission and serious adverse events. Adverse events were not reported.  AUTHORS' CONCLUSIONS: Intravenous magnesium sulfate may be associated with fewer hospital admissions, reduced length of hospital stay and improved dyspnoea scores compared to placebo. There is no evidence of a difference between magnesium infusion and placebo for NIV, lung function, oxygen saturation or adverse events. We found no evidence for ICU admission, endotracheal intubation, serious adverse events or mortality. For nebulised magnesium sulfate, we are unable to draw conclusions about its effects in COPD exacerbations for most of the outcomes. Studies reported possibly lower ICU admissions and a lesser degree of dyspnoea with magnesium inhalation compared to placebo; however, larger studies are required to yield a more precise estimate for these outcomes. Similarly, we could not identify any robust evidence for magnesium sulfate compared to ipratropium bromide. Future well-designed multicentre trials with larger samples are required, including subgroups according to severity of exacerbations and COPD phenotypes.

Lipid specificity of the immune effector perforin

Perforin is a pore forming protein used by cytotoxic T lymphocytes to remove cancerous or virus-infected cells during the immune response. During the response, the lymphocyte membrane becomes refractory to perforin function by accumulating densely ordered lipid rafts and externalizing negatively charged lipid species. The dense membrane packing lowers the capacity of perforin to bind, and the negatively charged lipids scavenge any residual protein before pore formation. Using atomic force microscopy on model membrane systems, we here provide insight into the molecular basis of perforin lipid specificity.

Associations of Serum Magnesium with Brain Morphology and Subclinical Cerebrovascular Disease: The Atherosclerosis Risk in Communities-Neurocognitive Study

Circulating magnesium has been associated with a lower risk of dementia, but the physiologic effects by which magnesium may prevent neurological insults remain unclear. We studied 1466 individuals (mean age 76.2 ± 5.3, 28.8% black, 60.1% female) free of prevalent stroke, with measured serum magnesium and with available MRI scans obtained in 2011–2013, participating in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). Cross-sectional differences in frontal, temporal, parietal, and occipital lobe volume, along with deep grey matter, total brain, and white matter hyperintensity volume across serum magnesium (categorized into quintiles and per standard deviation increases) were assessed using multiple linear regression. We also examined associations of magnesium with the prevalence of cortical, subcortical, and lacunar infarcts using multiple logistic regression. After adjusting for demographics, biomarkers, medications, and cardiometabolic risk factors, higher circulating magnesium was associated with greater total brain volume and frontal, temporal, and parietal lobe volumes (volumes 0.14 to 0.19 standard deviations higher comparing Q5 to Q1). Elevated magnesium was also associated with lower odds of subcortical infarcts (OR (95%CI): 0.44 (0.25, 0.77) comparing Q5 to Q1) and lacunar infarcts (OR (95%CI): 0.40 (0.22, 0.71) comparing Q5 to Q1). Elevated serum magnesium was cross-sectionally associated with greater brain volumes and lower odds of subclinical cerebrovascular disease, suggesting beneficial effects on pathways related to neurodegeneration and cerebrovascular damage. Further exploration through prospective analyses is needed to assess increasing circulating magnesium as a potential neuroprotective intervention.

Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

Synthesis, Characterization, and Cellular Uptake of Magnesium Maltol and Ethylmaltol Complexes

Magnesium deficiency and/or deficit (hypomagnesemia, <0.75 mmol/L in the blood) has become a recognized problem in healthcare and clinical settings. Concomitantly, supplementation has become recognized as the primary means of mitigating such deficiencies. Common magnesium supplements typically suffer from shortcomings: rapid dissociation and subsequent laxation (magnesium salts: e.g., magnesium chloride), poor water solubility (magnesium oxides and hydroxides), poor characterizability (magnesium chelates), and are/or use of non-natural ligands. To this end, there is a need for the development of fully characterized, water-soluble, all-natural magnesium compounds. Herein, we discuss the synthesis, solution and solid-state characterization, aqueous solubility, and cellular uptake of magnesium complexes of maltol and ethylmaltol, ligands whose magnesium complexes have yet to be fully explored.

Integrating supplementation in the management of patients with heart failure: an evidence-based review

INTRODUCTION

Complementary, alternative and integrative medicine includes a myriad of therapies including herbal medicines, vitamins, dietary interventions and more, that are taken alone or in adjunct to standard conventional treatment. Often the main goals are to slow progression of disease, increase effectiveness of a drug, reduce side effects and improve quality of life. The study of these therapies and their influence in heart failure is not new. However, even for an experienced clinician, a gap exists between the literature and the application of knowledge to make a confident recommendation.

AREAS COVERED

This review has a focus on specific supplements that are commonly used for individuals with HF. It discusses the mechanism of action, expected benefits, potential adverse effects, suggested doses, forms and drug interactions of these therapies. The literature search methodology included using medical subject headings terms to search in PubMed. Articles used were screened and critically appraised by the authors of this review.

EXPERT OPINION

There are promising outcomes pertaining to the use of CAM in patients with HF. Advances in large scale, randomized, placebo-controlled trials are necessary to support evidence-based decision making regarding the use of supplements in conjunction, and in comparison, to conventional therapies for heart failure.

STUDIES OF MAGNESIUM AND PHOSPHORUS COMBINED MEDICATION BASED ON CASEIN

Aim. The Department of Biochemistry and Physiology of Animals, named after Academician Guly NUBIP of Ukraine, developed magnesium and phosphorus combined medication based on casein. Our aim was to test its bioavailability based on the ability to be hydrolyzed by a mixture of pancreatic digestive enzymes trypsin and chymotrypsin, also check the absence of cytotoxic effects on cell cultures. Methods. To assess bioavailability, we used hydrolysis of the medication with a mixture of trypsin and chymotrypsin, followed by detection of hydrolysis products by polyacrylamide gel electrophoresis. A standard MTT-test performed on both MT-4 and Namalva cell lines was used to assess cytotoxic effects. Results. Based on electrophoresis data, it was found that despite chemical modifications of the natural casein, the medication based on it is characterized by a high ability to hydrolyze by digestive enzymes under the same conditions as casein. Also, an MTT-test demonstrates that the medication has no cytotoxic properties against cell lines MT-4 and Namalva. Conclusions. Since the negative effects of the drug associated with its digestibility and toxicity have not been observed, it is recommended to continue the study of its effects on living organisms.

Pathophysiology of Drug-Induced Hypomagnesaemia

Magnesium (Mg²⁺) is the second most abundant intracellular and fourth extracellular cation found in the body and is involved in a wide range of functions in the human cell and human physiology. Its role in most of the enzyme processes (ATP-ases)-stabilisation of nucleic acids (DNA, RNA), regulation of calcium and potassium ion channels, proliferation, glucose metabolism and apoptosis-make it one of the most important cations in the cell. Three pathogenetic mechanisms are mainly implicated in the development of hypomagnesaemia: reduced food intake, decreased intestinal absorption and increased renal excretion of Mg²⁺. This review presents the function of Mg²⁺, how it is handled in the kidney and the drugs that cause hypomagnesaemia. The frequency and the number of drugs like diuretics and proton-pump inhibitors (PPIs) that are used daily in medical practice are discussed in order to prevent and treat adverse effects by providing an insight into Mg²⁺ homeostasis.

Patients characteristics and health outcomes in patients hospitalized with hypomagnesemia: a retrospective study from a single center in the Northern Territory of Australia

AIM

This research aimed to study the clinical and biochemical characteristics and health outcomes of patients admitted and found to have hypomagnesemia in an Australian hospital with a high proportion of Indigenous Australians.

METHODS

A retrospective cohort study was conducted of all patients with hypomagnesemia hospitalised between 1st August 2008 and 31st December 2014 at Royal Darwin Hospital (RDH). All relevant demographic, clinical, and biochemical were collected from patients' medical records. The hospital database was reviewed in January 2018 for mortality of all included patients.

RESULTS

876 patients had been admitted with a confirmed diagnosis of hypomagnesemia during the study period, with mean follow up period of 4.0 ±2.7 years. The mean age at admission was 52.4 ± 19.1 years, 52.2% were females and, 56.5% were Indigenous Australians. Chronic kidney disease (99.7%), excessive alcohol consumption (45.7%), hypertension (43.9%), and respiratory diseases (15.0%) were the most common conditions in these patients. Hypomagnesemia was associated with prolonged length of hospital stay. Most patients did not receive treatment for hypomagnesaemia during admission. During the follow-up period, 38.6% of patients died, and the most common causes of death were malignancies (29.9%).

CONCLUSION

Hypomagnesemia was a common and under-treated condition in hospitalised patients and was associated with poor health outcomes. Therefore, hospitals should develop guidelines for replacing and monitoring magnesium levels during hospitalisation, achieving better outcomes. This article is protected by copyright. All rights reserved.

Magnesium Metabolism in Chronic Alcohol-Use Disorder: Meta-Analysis and Systematic Review

Chronic alcohol-use disorder has been imputed as a possible cause of dietary magnesium depletion. The purpose of this study was to assess the prevalence of hypomagnesemia in chronic alcohol-use disorder, and to provide information on intracellular magnesium and on its renal handling. We carried out a structured literature search up to November 2020, which returned 2719 potentially relevant records. After excluding non-significant records, 25 were retained for the final analysis. The meta-analysis disclosed that both total and ionized circulating magnesium are markedly reduced in chronic alcohol-use disorder. The funnel plot and the Egger’s test did not disclose significant publication bias. The I²-test demonstrated significant statistical heterogeneity between studies. We also found that the skeletal muscle magnesium content is reduced and the kidney’s normal response to hypomagnesemia is blunted. In conclusion, magnesium depletion is common in chronic alcohol-use disorder. Furthermore, the kidney plays a crucial role in the development of magnesium depletion.

Synthesis and Chemical and Biological Evaluation of a Glycine Tripeptide Chelate of Magnesium

Magnesium (Mg2+) plays a crucial role in over 80% of all metabolic functions. It is becoming increasingly apparent that magnesium deficiency (hypomagnesemia) may play an important role in chronic disease. To counteract magnesium deficiency, there is an unmet clinical need to develop new fully characterized, highly bioavailable, and substantially water-soluble magnesium supplements. To this end, triglycine (HG3), a tripeptide of the amino acid glycine, was chosen as a chelating ligand for magnesium, given its natural occurrence and water solubility, and entropically-driven metal binding. Herein, we discuss the synthesis, chemical and physical characterization, and cellular uptake of a magnesium triglycine chelate (MgG3), an octahedral complex with extraordinary water solubility and improved cellular uptake in CaCo-2 cells than select commonly used magnesium supplements.

Investigation of hypomagnesaemia prevalence and underlying aetiology in a hospitalised cohort of dogs with ionised hypocalcaemia

OBJECTIVES

Calcium is the most abundant mineral in the body and plays a critical role in a wide range of physiological processes. Low concentrations of ionised calcium, the most metabolically available form of calcium, have been linked to an increased risk of adverse clinical outcomes in dogs. Magnesium plays an important role in parathyroid hormone function. The objective of this study was to define the prevalence and aetiology of hypomagnesaemia in a hospitalised cohort of dogs with ionised hypocalcaemia (IHC).

METHODS

A total magnesium reference interval was established using serum biochemistry results from 346 clinically healthy dogs. The clinical records of dogs with IHC were reviewed, and concurrent serum magnesium concentrations were recorded alongside clinical signs and underlying aetiology. The prevalence, clinical presentation and aetiology of hypomagnesaemia were examined in the IHC population.

RESULTS

Two hundred and ninety-five IHC dogs were identified. Hypomagnesaemia was identified in 22%. Total magnesium concentration was significantly higher in dogs with renal disease. The most common cause of concurrent hypomagnesaemia and IHC was gastrointestinal diseases.

CONCLUSION

Low concentrations of serum magnesium occur in approximately one fifth of all dogs with IHC. Further studies are required to clarify the link between magnesium status, IHC and clinical outcome.

Hypomagnesemia in the Cancer Patient

Hypomagnesemia is a common medical problem that contributes to the morbidity and mortality of patients with cancer. This review summarizes magnesium physiology and highlights the mechanisms underlying magnesium disturbances due to cancer and cancer treatment. The causes of hypomagnesemia can be categorized according to the pathophysiologic mechanism: decreased intake, transcellular shift, gastrointestinal losses, and kidney losses. Patients with cancer are at risk for opportunistic infections, frequently experience cardiovascular complications, and often receive classes of medications that cause or exacerbate hypomagnesemia. Also, cancer-specific therapies are responsible for hypomagnesemia, including platinum-based chemotherapy, anti-EGF receptor mAbs, human EGF receptor-2 target inhibitors (HER2), and calcineurin inhibitors. Urinary indices, such as the fractional excretion of magnesium, can provide useful information about the etiology. The management of hypomagnesemia depends on the magnitude of hypomagnesemia and the underlying cause. We recommended checking serum magnesium at the beginning of treatment and as part of routine monitoring throughout cancer treatment. Opportunities exist for potential research and practice improvement, including further characterization of hypomagnesemia regarding the clinical effect on cancer outcomes, preventing hypomagnesemia in patients receiving high-risk anticancer agents, and developing effective therapeutic strategies.

Going to the roots of reduced magnesium dietary intake: A tradeoff between climate changes and sources

Magnesium is essential in plants where it is associated with chlorophyll pigments and serves as a cofactor of enzymes implicated in photosynthesis and metabolism. It is an essential nutrient for animals, involved in hundreds metabolic reaction and crucial for the biological activity of ATP. Not surprisingly, magnesium deficiency is detrimental for the health of plants and animals. In humans, subclinical magnesium deficiency is common and generates chronic inflammation, which is the common denominator of a wide range of mental and physical health problems from metabolic diseases to cognitive impairment, from osteopenia and sarcopenia to depression. It is ascertained that magnesium content in fruits and vegetables dropped in the last fifty years, and about 80% of this metal is lost during food processing. As a consequence, a large percentage of people all over the world does not meet the minimum daily magnesium requirement. In this scoping review, we summarize how agronomic and environmental factors, including global warming, affect magnesium content and availability in the soil and, consequently, in the food chain, with the aim of attracting the interest of botanists, agronomists, animal and human nutritionists and physicians to work on a strategy that grants adequate magnesium intake for everybody.

Hypomagnesemia is underestimated in children with HNF1B mutations

BACKGROUND

Hypomagnesemia in patients with congenital anomalies of the kidneys and urinary tract or autosomal dominant tubulointerstitial kidney disease is highly suggestive of HNF1B-associated disease. Intriguingly, the frequency of low serum Mg²⁺ (sMg) level varies and is lower in children than in adults with HNF1B mutations that could be partially due to application of inaccurate normal limit of sMg, irrespective of age and gender. We aimed to re-assess cross-sectionally and longitudinally the frequency of hypomagnesemia in HNF1B disease by using locally derived reference values of sMg.

METHODS

Fourteen children with HNF1B-associated kidney disease were included. Control group comprising 110 subjects served to generate 2.5th percentiles of sMg as the lower limits of normal.

RESULTS

In both controls and patients, sMg correlated with age, gender, and fractional excretion of Mg²⁺. In girls, sMg concentration was higher than in boys when analyzed in the entire age spectrum (p < 0.05). In HNF1B patients, mean sMg was lower than in controls as compared with respective gender- and age-specific interval (p < 0.001). Low sMg levels (< 0.7 mmol/l) were found in 21.4% of patients at diagnosis and 36.4% at last visit, which rose to 85.7% and 72.7% respectively when using the age- and gender-adjusted reference data. Similarly, in the longitudinal observation, 23% of sMg measurements were < 0.7 mmol/l versus 79.7% when applying respective references.

CONCLUSIONS

Hypomagnesemia is underdiagnosed in children with HNF1B disease. sMg levels are age- and gender-dependent; thus, the use of appropriate reference data is crucial to hypomagnesemia in children.

The Coordination Chemistry of Bio-Relevant Ligands and Their Magnesium Complexes

The coordination chemistry of magnesium (Mg²⁺) was extensively explored. More recently; magnesium; which plays a role in over 80% of metabolic functions and governs over 350 enzymatic processes; is becoming increasingly linked to chronic disease—predominantly due to magnesium deficiency (hypomagnesemia). Supplemental dietary magnesium utilizing biorelevant chelate ligands is a proven method for counteracting hypomagnesemia. However, the coordination chemistry of such bio-relevant magnesium complexes is yet to be extensively explored or elucidated. It is the aim of this review to comprehensively describe what is currently known about common bio-relevant magnesium complexes from the perspective of coordination chemistry.

Variations in Magnesium Concentration Are Associated with Increased Mortality: Study in an Unselected Population of Hospitalized Patients

Dysmagnesemia is a serious disturbance of microelement homeostasis. The aim of this study was to analyze the distribution of serum magnesium concentrations in hospitalized patients according to gender, age, and result of hospitalization. The study was conducted from February 2018 to January 2019 at the Central Clinical Hospital in Warsaw. Laboratory test results from 20,438 patients were included in this retrospective analysis. When a lower reference value 0.65 mmol/L was applied, hypermagnesemia occurred in 196 patients (1%), hypomagnesemia in 1505 patients (7%), and normomagnesemia in 18,711 patients (92%). At a lower reference value of 0.75 mmol/L, hypomagnesemia was found in 25% and normomagnesemia in 74% of patients. At a lower reference value of 0.85 mmol/L, hypomagnesemia was found in 60% and normomagnesemia in 39% of patients. Either hypo- or hyper-magnesemia was associated with increased risk of in-hospital mortality. This risk is the highest in patients with hypermagnesemia (40.1% of deaths), but also increases inversely with magnesium concentration below 0.85 mmol/L. Serum magnesium concentration was not gender-dependent, and there was a slight positive correlation with age (p < 0.0001, r = 0.07). Large fluctuations in serum magnesium level were associated with increased mortality (p = 0.0017). The results indicate that dysmagnesemia is associated with severe diseases and generally severe conditions. To avoid misdiagnosis, an increase of a lower cut-off for serum magnesium concentration to at least 0.75 mmol/L is suggested.

Measurement of Serum Ionized Magnesium in Capd Patients

Objective

To evaluate the magnesium status of continuous ambulatory peritoneal dialysis (CAPD) patients using a new method for assessing the level of the ionized fraction a serume magnesiumy.

Design

Serum ionized magnesium was measured in CAPD patients using the ion-selective electrode for Mg2+.

Setting

The Dialysis Unit of Tampere University Hospital.

Patients

Twenty -six patients on CAPD (age: 21 -81 years, mean 54 ± 16 years; duration of CAPD: 3 -52 months, mean 13 months), and 26 sex and age-matched healthy controls.

Results

Both serum ionized magnesium (0.73 ± 0.11 mmol/L vs 0.56 ± 0.07 mmol/L, p < 0.001) and total magnesium (1.11 ± 0.22 vs 0.81 ± 0.08 mmol/L, p < 0.01) were higher in CAPD patients than in sex and agematched controls. The ionized magnesium fraction of total magnesium was slightly lower in dialysis patients in spite of the fact that 16/26 patients had serum albumin less than 36 g/L. Hypermagnesemia (mean serum ionized magnesium 0.78± 0.10 mmol/L) was observed in the 13 of 26 patients with 0.75 mmol/L Mg2+ dialysate; those with lower magnesium dialysate (Mg2+ 0.50 mmol/L in 10/26 and Mg2+ 0.25 mmol/L in 3/26) had mean serum ionized magnesium at the upper normal margin (0.69 ± 0.10 mmol/L).

Conclusion

In CAPD patients with Mg2+ 0.5 0.75 mmol/L in their dialysis fluid, both serum ionized and total magnesium concentrations were higher but the ionized/total magnesium ratio was lower than in healthy control subjects. Use of ion-selective electrodes to measure ionized magnesium may be a more useful methodology than measuring total magnesium in the evaluation of magnesium status of CAPD patients, because it is not infuenced by hypoalbuminemia or increased complexed fraction of magnesium often present in dialysis patients.

Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.

The Role of Magnesium in the Development of Cardiovascular Diseases and the Possibility of their Prevention and Correction with Magnesium Preparations (Part 1)

The article is devoted to the influence of magnesium on the homeostasis of the body and, in particular, on the cardiovascular system. It describes the importance of the presence and effects of magnesium on various key processes and functions occurring in the body. The reasons for the lack of magnesium and ways to replenish it both in the natural way (eating, certain foods) and magnesium preparations are considered. The article provides examples of large randomized studies that prove the importance of the influence of normal magnesium levels on human health in general and on the state of the cardiovascular system. These studies show how magnesium deficiency increases the risk of cardiovascular diseases and how it can be reduced. It is also shown which trace elements and vitamins are closely related to magnesium metabolism, and how they (in particular, potassium and vitamin B6) improve and facilitate the normalization of magnesium levels. It is noted how comorbidity decreases with the normalization of magnesium level – the higher the magnesium level in the blood plasma (closer to the upper limit and more), the less comorbidity and longer life expectancy. Magnesium is an absolutely essential ion and a good medicine. Magnesium deficiency and hypomagnesemia are quite common, difficult to diagnose (due to underestimation and rare level control) and accompany many diseases of the cardiovascular system and beyond. The widespread use of organic magnesium salts would improve the situation as a whole, due to their universal multiple effect on many processes in the body. This is an integral part of therapeutic and preventive measures in patients with already existing diseases and in people who do not have diseases, but who are at risk due to existing hypomagnesemia.

Low dietary magnesium intake alters vitamin D-parathyroid hormone relationship in adults who are overweight or obese

Vitamin D metabolism is dependent on magnesium (Mg) as a cofactor; therefore, poor Mg status may alter the relationship between vitamin D metabolite serum 25-hydroxyvitamin D (s25OHD) and serum parathyroid hormone (sPTH). We hypothesized that low dietary Mg intake may alter sPTH response to s25OHD in a population with excess body weight, thereby leading to a worsening of cardiometabolic health. To explore this hypothesis, we conducted a cross-sectional study on adults who were either overweight or obese (owt/ob). Dietary Mg intake was measured using a Mg food frequency questionnaire (MgFFQ). Body composition information was measured using Dual Energy X-ray Absorptiometry (DXA). Blood samples were obtained for all biochemical analyses. A total of 57 participants, 22 to 65 years of age, with a body mass index between 25 to 45 kg/m² were divided into 3 groups, according to dietary Mg intake percentiles (Low Mg Group = <33 percentile, Medium Mg Group = 33 to 66 percentile, High Mg Group = >66 percentile). Higher s25OHD was negatively associated with lower sPTH in the High Mg Intake group (r = -0.472, P = .041), but not in other groups. A positive relationship between s25OHD and serum high-molecular weight adiponectin concentrations was observed in the High Mg Group (r = 0.532, r = 0.022), but not in other groups. Serum Interleukin-6 concentrations were negatively associated with s25OHD (r = -0.316, P = .017) for the entire study group. Based on these results, our study demonstrated that a low dietary Mg intake may alter PTH response to 25OHD.

Cyanidin Increases the Expression of Mg2+ Transport Carriers Mediated by the Activation of PPARα in Colonic Epithelial MCE301 Cells

Mg²⁺ deficiency may be involved in lifestyle-related diseases, including hypertension, cardiovascular diseases, and diabetes mellitus. Dietary Mg²⁺ is absorbed in the intestine mediated through transcellular and paracellular pathways. However, there is little research into what factors upregulate Mg²⁺ absorption. We searched for food constituents that can increase the expression levels of Mg²⁺ transport carriers using mouse colonic epithelial MCE301 cells. Cyanidin, an anthocyanidin found in black beans and berries, increased the mRNA levels of Mg²⁺ transport carriers including transient receptor potential melastatin 6 (TRPM6) channel and cyclin M4 (CNNM4). The cyanidin-induced elevation of Mg²⁺ transport carriers was blocked by GW6471, a peroxisome proliferator-activated receptor α (PPARα) inhibitor, but not by PPARγ, PPARδ, and protein kinase A inhibitors. Cyanidin-3-glucoside showed similar results to cyanidin. Cyanidin increased the protein levels of TRPM6 and CNNM4, which were distributed in the apical and lateral membranes, respectively. The nuclear localization of PPARα and reporter activities of Mg²⁺ transport carriers were increased by cyanidin, which were inhibited by GW6471. The cyanidin-induced elevation of reporter activity was suppressed by a mutation in a PPAR-response element. Fluorescence measurements using KMG-20, an Mg²⁺ indicator, showed that Mg²⁺ influx and efflux from the cells were enhanced by cyanidin, and which were inhibited by GW6471. Furthermore, cyanidin increased paracellular Mg²⁺ flux without affecting transepithelial electrical resistance. We suggest that cyanidin increases intestinal Mg²⁺ absorption mediated by the elevation of TRPM6 and CNNM4 expression, and may constitute a phytochemical that can improve Mg²⁺ deficiency.

Magnesium: A Magic Bullet for Cardiovascular Disease in Chronic Kidney Disease?

Magnesium is essential for many physiological functions in the human body. Its homeostasis involves dietary intake, absorption, uptake and release from bone, swifts between the intra- and extracellular compartment, and renal excretion. Renal excretion is mainly responsible for regulation of magnesium balance. In chronic kidney disease (CKD), for a long time the general policy has been limiting magnesium intake. However, this may not be appropriate for many patients. The reference ranges for magnesium are not necessarily optimal concentrations, and risks for insufficient magnesium intake exist in patients with CKD. In recent years, many observational studies have shown that higher (in the high range of “normal” or slightly above) magnesium concentrations are associated with better survival in CKD cohorts. This review gives an overview of epidemiological associations between magnesium and overall and cardiovascular survival in patients with CKD. In addition, potential mechanisms explaining the protective role of magnesium in clinical cardiovascular outcomes are described by reviewing evidence from in vitro studies, animal studies, and human intervention studies with non-clinical endpoints. This includes the role of magnesium in cardiac arrhythmia, heart failure, arterial calcification, and endothelial dysfunction. Possible future implications will be addressed, which will need prospective clinical trials with relevant clinical endpoints before these can be adopted in clinical practice.

Deregulated renal magnesium transport during lipopolysaccharide-induced acute kidney injury in mice

Magnesium (Mg²⁺) abnormalities during sepsis have been reported, but the underlying mechanisms during acute inflammation are poorly understood. We hypothesized that a decrease in GFR and/or changes in transporters or channels for Mg²⁺ could be responsible for the observed Mg²⁺ abnormalities. Therefore, we studied the metabolism of Mg²⁺ in a murine model of endotoxemia. LPS-induced hypermagnesemia was paralleled by a decrease in creatinine clearance and an increase in the fractional excretion of Mg²⁺. In agreement with an altered renal Mg²⁺ handling, endotoxemia decreased the renal expression of claudin (Cldn) 10b, Cldn16, Cldn19, parvalbumin, and of the solute carrier family (Slc) 41a3. Further, LPS increased the renal expression of Cldn14 and Slc41a1. The renal expression of the transient receptor potential melastin (Trpm) 6, Trpm7, and of cyclin M (Cnnm) 2 was unaltered in response to LPS. In vitro studies support a direct effect on the expression of Cldn10b, Cldn14, Cldn16, and Cldn19. Further, endotoxemia increased the fractional excretion of sodium, which was paralleled by a decrease of important renal sodium transporters. In the large intestine, the expression of Trpm7 was increased in response to LPS, whereas the expression of Trpm6 was decreased. Cnnm4 mRNA levels were unchanged in the large intestine. Further, Cldn12 and Na⁺-H⁺ exchanger 3 (Slc9a3) expressions were decreased in the small intestine in response to LPS. Our findings indicate that endotoxemia is associated with hypermagnesemia and a disturbed Mg²⁺ handling. It seems likely that LPS-induced hypermagnesemia is due to the decrease in renal function in response to LPS.

Renal ischemia-reperfusion injury impairs renal calcium, magnesium, and phosphate handling in mice

Fibroblast growth factor 23 (FGF23) levels are elevated in patients with acute kidney injury (AKI). The consequences on renal Ca²⁺, Mg²⁺, and P_i regulatory mechanisms are unknown. We hypothesized that renal ischemia-reperfusion (I/R) injury alters the expression of important renal Ca²⁺, Mg²⁺, and P_i transport proteins. I/R injury was induced in male C57BL/6 mice by clamping both renal arteries for 27 min. Mice were investigated 18 h later. The mRNA and protein levels of renal Ca²⁺, Mg²⁺, and P_i transport proteins were measured by RT-qPCR and western blot analysis. I/R injury-induced hyperphosphatemia and hypermagnesemia were paralleled by a decrease in glomerular filtration rate and an increase in the fractional excretion of Ca²⁺, Mg²⁺, and P_i. I/R injury affected the fibroblast growth factor 23 (FGF23)-klotho-vitamin D axis by increasing plasma levels of FGF23 and downregulation of renal klotho expression. Plasma levels of PTH and 1,25-dihydroxyvitamin D₃ were unchanged. Further, downregulation of key genes for paracellular reabsorption of Ca²⁺ and Mg²⁺ (claudin (Cldn)2, Cldn10b, Cldn16, Cldn19) and for active transcellular transport of Ca²⁺, Mg²⁺, and P_i (calbindin-D_28K, Ncx1, Pmca4, Cnnm2, Trpm7, NaP_i-2a, and NaP_i-2c) was observed. However, renal expression of Trpv5 and Trpv6 was increased. In vitro studies support a direct effect of proinflammatory cytokines on the mRNA expression of Cldn16, Cldn19, and Trpv6. Our findings indicate that renal I/R injury increases FGF23 blood levels independent of PTH and 1,25-dihydroxyvitamin D₃. This increase is associated with hypermagnesemia, hyperphosphatemia, and increased or decreased expression of specific renal Ca²⁺, Mg²⁺, and P_i transporters, respectively.

Low Levels of Branched Chain Amino Acids, Eicosapentaenoic Acid and Micronutrients Are Associated with Low Muscle Mass, Strength and Function in Community-Dwelling Older Adults

BACKGROUND

Sarcopenia, the age-related decrease in muscle mass and function can result in adverse health outcomes and subsequent loss of independence. Inadequate nutrition is an important contributor to the aetiology of sarcopenia, and dietary strategies are studied to prevent or delay this geriatric syndrome.

OBJECTIVE

The present study investigated whether there is an association between biochemical nutrient status markers, muscle parameters and sarcopenia in community-dwelling older adults.

DESIGN

Data from the cross-sectional Maastricht Sarcopenia study (MaSS) were used, in which skeletal muscle index (SMI), 4 meter gait speed, 5 times chair stand and handgrip strength were assessed among older adults (n=227). Sarcopenia was defined following the algorithm of the European Working Group on Sarcopenia in Older People. Fasted blood samples were analyses on amino acids levels, RBC phospholipid profile, 25-hydroxyvitamin D (25(OH)D), α-tocopherol, magnesium and homocysteine were determined in fasted blood levels. Generalized linear modelling and logistic regression were used for data analysis.

RESULTS

Lower blood levels of essential amino acids (EAA), total branched-chain amino acids (BCAA) and leucine were associated with lower SMI (P<0.001), strength (P<0.001) and longer time to complete the chair stand (P<0.05), whereas no association was found for total amino acids (TAA). Lower levels of eicosapentaenoic acid (EPA), 25(OH)D and homocysteine were associated with lower muscle parameter values (P<0.05). No significant associations were found for SFA, MUFA, PUFA, n-3 and n-6 fatty acids, docosahexaenoic acid (DHA), α-tocopherol-cholesterol ratio and magnesium. Sarcopenia was more frequent among those with lower levels of leucine, BCAA, EAA, EPA, 25(OH)D and higher levels of homocysteine (P<0.05). Age and BMI were identified as relevant covariates. A robust association was only found for lower gait speed and lower 25(OH)D levels.

CONCLUSION

Compromised muscle parameters are associated with low blood values of specific amino acids, fatty acids, vitamin D and high homocysteine.

Severe hypermagnesemia induced by magnesium oxide ingestion: a case series

Hypermagnesemia is generally considered an exceptional iatrogenic condition usually caused by magnesium-containing cathartics. In particular, this condition often develops when magnesium-containing cathartics are administered to elderly patients with renal insufficiency or bowel movement dysfunction. Although magnesium oxide (MgO) is widely prescribed as a laxative, serum magnesium concentration has not been examined in most cases. In this report, we present the cases of four elderly patients with constipation and symptomatic hypermagnesemia caused by MgO ingestion, one of which had a lethal course. All of the patients were older than 65 years and with renal dysfunction. In addition, they had difficulties in expressing their symptoms because of cerebrovascular events or dementia. These cases suggest that hypermagnesemia caused by magnesium-containing cathartics is more likely to develop than previously recognized and that physicians should be aware that patients with chronic kidney disease and the elderly are at risk of hypermagnesemia on magnesium administration. We recommend serum magnesium monitoring for high-risk patients after initial prescription or dose increase.

Low magnesium intake is associated with increased knee pain in subjects with radiographic knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

As magnesium mediates bone and muscle metabolism, inflammation, and pain signaling, we aimed to evaluate whether magnesium intake is associated with knee pain and function in radiographic knee osteoarthritis (OA).

METHODS

We investigated the associations between knee pain/function metrics and magnesium intake from food and supplements in 2548 Osteoarthritis Initiative cohort participants with prevalent radiographic knee OA (Kellgren-Lawrence score ≥2). Magnesium intake was assessed by Food Frequency Questionnaire (FFQ) at baseline. WOMAC and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were reported annually with total follow up of 48 months. Analyses used linear mixed models.

RESULTS

Among participants with baseline radiographic knee OA the mean total magnesium intake was 309.9 mg/day (SD 132.6) for men, and 287.9 mg/day (SD 118.1) for women, with 68% of men and 44% of women below the estimated average requirement. Subjects with lower magnesium intake had worse knee OA pain and function scores, throughout the 48 months (P < 0.001). After adjustment for age, sex, race, body mass index (BMI), calorie intake, fiber intake, pain medication use, physical activity, renal insufficiency, smoking, and alcohol use, lower magnesium intake remained associated with worse pain and function outcomes (1.4 points higher WOMAC and 1.5 points lower KOOS scores for every 50 mg of daily magnesium intake, P < 0.05). Fiber intake was an effect modifier (P for interaction <0.05). The association between magnesium intake and knee pain and function scores was strongest among subjects with low fiber intake.

CONCLUSION

Lower magnesium intake was associated with worse pain and function in knee OA, especially among individuals with low fiber intake.

Analysis of serum magnesium ions in dogs exposed to external stress: A pilot study

Magnesium ions (Mg²⁺) are essential for various enzymatic reactions in the body associated with energy production and activation of the muscles and nerves. Mg²⁺ is also involved in blood pressure regulation, maintenance of body temperature, and glucose metabolism. Although various factors including foods and physical conditions have been reported to change serum Mg²⁺ status in humans, serum Mg²⁺ in dogs exposed to external stress has been unclear. In this study, we examined serum levels of Mg²⁺ in dogs at different conditions using the guide dog candidates for the blind. Serum Mg²⁺ was decreased in winter and increased in summer. Guide dog candidates in an elementary class of the training showed markedly lower levels of serum Mg²⁺, compared with that of dogs in an advanced class. When healthy adult dogs were subjected to forced exercise using a treadmill, a significant reduction in serum Mg²⁺ levels was observed, particularly in winter. These findings suggest that serum levels of Mg²⁺ may be influenced by weather fluctuation such as air temperature, nervousness in unaccustomed situations, age, and physical stress induced by exercise. The results indicate that Mg²⁺ supplementation should be considered for working dogs, dogs moving or traveling to a new environment, and dogs during winter.

Fatal Hypermagnesemia Due to Laxative Use

We report a case of fatal hypermagnesemia in a 53-year-old woman admitted for acute exacerbation of chronic obstructive pulmonary disease and with a history of chronic constipation treated regularly with magnesium-containing laxatives. On admission, her magnesium level was 2.0mg/dL, which rose to a peak of 10.8mg/dL despite hydration and diuresis in the presence of a normal kidney function. Continuous renal replacement therapy was promptly initiated, which reduced her serum magnesium levels, but her condition continued to deteriorate precipitously progressing to shock leading to oligoanuric renal failure, and she died 2 days later. A review of the literature shows that though rare and often unsuspected, severe hypermagnesemia frequently results in death even in individuals with normal renal function despite renal replacement therapy. In patients with constipation, retention of magnesium-based laxative in the gut apparently serves as a reservoir for continuous magnesium absorption and contributes to mortality.

Magnesium lactate in the treatment of Gitelman syndrome: patient-reported outcomes

Background: Gitelman syndrome (GS) is a rare recessively inherited renal tubulopathy associated with renal potassium (K) and magnesium (Mg) loss. It requires lifelong K and Mg supplementation at high doses that are at best unpalatable and at worst, intolerable. In particular, gastrointestinal side effects often limit full therapeutic usage.

Methods: We report here the analysis of a cohort of 28 adult patients with genetically proven GS who attend our specialist tubular disorders clinic, in whom we initiated the use of a modified-release Mg preparation (slow-release Mg lactate) and who were surveyed by questionnaire.

Results: Twenty-five patients (89%) preferred the new treatment regimen. Of these 25, 17 (68%) regarded their symptom burden as improved and seven reported no worsening. Of the 25 who were not Mg-treatment naïve, 13 (59%) patients reported fewer side effects, 7 (32%) described them as the same and only 2 (9%) considered side effects to be worse. Five were able to increase their dose without ill-effect. Overall, biochemistry improved in 91% of the 23 patients switched from therapy with other preparations who chose to continue the modified-release Mg preparation. Eleven (48%) improved both their Mg and K mean levels, 3 (13%) improved Mg levels only and in 7 cases (30%), K levels alone rose.

Conclusions: Patient-reported and biochemical outcomes using modified-release Mg supplements were very favourable, and patient choice should play a large part in choosing Mg supplements with GS patients.

Electrolyte disorders with platinum-based chemotherapy: mechanisms, manifestations and management

Platinum chemotherapy, particularly cisplatin, is commonly associated with electrolyte imbalances, including hypomagnesemia, hypokalemia, hypophosphatemia, hypocalcemia and hyponatremia. The corpus of literature on these dyselectrolytemias is large; the objective of this review is to synthesize the literature and summarize the mechanisms responsible for these particular electrolyte disturbances in the context of platinum-based treatment as well as to present the clinical manifestations and current management strategies for oncologists and primary care physicians, since the latter are increasingly called on to provide care for cancer patients with medical comorbidities. Correct diagnosis and effective treatment are essential to improved patient outcomes.

Clinical aspects of magnesium physiology in patients on dialysis

Magnesium balance is infrequently discussed in the dialysis population, and the clinical consequences of derangements in magnesium homeostasis are incompletely understood. There is an association between hypomagnesemia and adverse outcomes including increases in cardiovascular disease and mortality, while elevated magnesium levels have also been linked with complications such as osteomalacia. In this review, we discuss the features of magnesium physiology relevant to dialysis patients and provide an updated summary of the literature linking magnesium derangements with bone disease, cardiovascular disease, sudden cardiac death, and mortality.