Hypermagnesemia is a strong independent risk factor for mortality in critically ill patients: results from a cross-sectional study

Hypermagnesemia is associated with poor outcomes during hospitalization

BACKGROUND

Hypermagnesemia is one of the vital electrolyte disturbances and is associated with such chronic conditions as cardiovascular, endocrinologic, renal diseases, and malignancy.

AIM

This study evaluates the association between hypermagnesemia and clinical course in hospitalized patients.

METHODS

This study was conducted at the University of Health Sciences Haseki Training and Research Hospital Internal Medicine Clinic. We evaluated a total of 3850 patients. 2130 patients have met the inclusion criteria were included in the study. Those who were discharged with healing were evaluated as having a good prognosis. Patients who died or were transferred to the intensive care unit (ICU) were defined as having a poor prognosis. We divided the patients' serum magnesium levels into four quartiles and examined the clinical course/conditions of the patients.

RESULTS

Of 2130 patients, 1013 (51.9%) were female. The mean age of patients with poor prognoses (69.2 ± 14.9) was higher than those with good prognoses (59.7 ± 19.1). Hypermagnesemia (4th quartile) was detected in 61 (33.9%), and hypomagnesemia (1st quartile) was found in 42 (23.3%) patients out of 180 patients with poor clinical outcomes. It was statistically significant that hypermagnesemia was more common in patients with poor prognoses (p: 0.002). Chronic kidney disease (CKD) was diagnosed in 258 (53.3%) of 484 hypermagnesemia patients. Hypermagnesemia was found to be more common in patients with CKD, which was statistically significant (p: 0.003).

CONCLUSIONS

Hypermagnesemia is associated with poor prognosis independent of comorbidities. Besides hypomagnesemia, hypermagnesemia should be considered a critical electrolyte imbalance.

Lower product of magnesium × potassium is associated with higher mortality in chronic hemodialysis patients: a cohort study

This study aimed to investigate the Mg × K product on the mortality risk of hemodialysis patients with concomitant hypokalemia and lower magnesium levels. This was a prospective observational study of patients in a HD center in southern Taiwan. A total of 444 HD patients were divided into 5 groups by the Mg × K product: group 1, bottom quintile, median Mg × K: 7.87, IQR: 7.03-8.12 (n = 89, age: 64 ± 13 years old); group 2, median Mg × K: 9.37, IQR: 8.97-9.86 (n = 89, age:62 ± 13 years old); group 3, median Mg × K: 10.95, IQR: 10.50-11.26 (n = 89, age:64 ± 13 years old); group 4, median Mg × K: 12.30, IQR: 11.87-12.82 (n = 89, 61 ± 12 years old); and group 5, top quintile, median Mg × K: 14.92, IQR:14.07-16.23 (n = 88, 62 ± 11 years old). The patients were followed up for 2 years to determine the risk of all-cause mortality. Patients with a lower Mg × K product had more comorbidities, malnutrition-inflammation status, and a higher mortality risk. Using multivariable Cox regression analysis, a higher Mg × K [HR, 0.89; 95%CI (0.81-0.98)] was found to be an independent predictor of better survival. HD patients with a lower Mg × K product had more comorbidities, a marked malnutrition-inflammation status, and were associated with long-term mortality. A higher Mg × K value is a favorable survival factor.

Hypermagnesemia in Clinical Practice

Hypermagnesemia is a relatively uncommon but potentially life-threatening electrolyte disturbance characterized by elevated magnesium concentrations in the blood. Magnesium is a crucial mineral involved in various physiological functions, such as neuromuscular conduction, cardiac excitability, vasomotor tone, insulin metabolism, and muscular contraction. Hypomagnesemia is a prevalent electrolyte disturbance that can lead to several neuromuscular, cardiac, or nervous system disorders. Hypermagnesemia has been associated with adverse clinical outcomes, particularly in hospitalized patients. Prompt identification and management of hypermagnesemia are crucial to prevent complications, such as respiratory and cardiovascular negative outcomes, neuromuscular dysfunction, and coma. Preventing hypermagnesemia is crucial, particularly in high-risk populations, such as patients with impaired renal function or those receiving magnesium-containing medications or supplements. Clinical management of hypermagnesemia involves discontinuing magnesium-containing therapies, intravenous fluid therapy, or dialysis in severe cases. Furthermore, healthcare providers should monitor serum magnesium concentration in patients at risk of hypermagnesemia and promptly intervene if the concentration exceeds the normal range.

Initial Serum Magnesium Level Is Associated with Mortality Risk in Traumatic Brain Injury Patients

BACKGROUND

Electrolyte disorder is prevalent in traumatic brain injury (TBI) patients. This study is designed to explore the association between initial serum magnesium levels and mortality of TBI patients.

METHODS

TBI patients recorded in the Medical Information Mart for Intensive Care-III database were screened for this study. Logistic regression analysis was used to explore risk factors for mortality of included TBI patients. The restricted cubic spline (RCS) was applied to fit the correlation between initial serum magnesium level and mortality of TBI.

RESULTS

The 30-day mortality of included TBI patients was 17.0%. Patients with first-tertile and third-tertile serum magnesium levels had higher mortality than those of the second tertile. Univariate regression analysis showed that the serum magnesium level was not associated with mortality. Unadjusted RCS indicated the relationship between serum magnesium level mortality was U-shaped. After adjusting confounding effects, multivariate regression analysis presented that serum magnesium level was positively associated with mortality.

CONCLUSION

TBI patients with abnormally low or high levels of serum magnesium both have a higher incidence of mortality. At the same time, a higher initial serum magnesium level is independently associated with mortality in TBI patients. Physicians should pay attention to the clinical management of TBI patients, especially those with higher serum magnesium levels.

Association of magnesium abnormalities at intensive care unit admission with kidney outcomes and mortality: a prospective cohort study

BACKGROUND

Magnesium abnormalities have been associated with adverse kidney outcomes and mortality in critically ill patients, however, this association remains inconsistent. This study aimed to investigate the association of magnesium abnormalities at intensive care unit (ICU) admission with kidney outcomes (i.e., acute kidney injury (AKI) and kidney function recovery) and mortality risk in a large cohort of critically ill patients.

METHODS

A prospective cohort study was conducted by collecting data from three ICUs in Brazil. The ICU admission serum magnesium level was used to define hypomagnesemia (< 1.60 mg/dL) and hypermagnesemia (> 2.40 mg/dL). The Kidney Disease Improving Global Outcomes AKI Guideline was used to define AKI based on serum creatinine levels. Kidney function recovery was defined as full recovery, partial recovery, and non-recovery at ICU discharge. Mortality was screened up to 28 days during ICU stay.

RESULTS

A total of 7,042 patients was analyzed, hypomagnesemia was found in 18.4% (n = 1,299) and hypermagnesemia in 4.4% (n = 311). Patients with hypomagnesemia were 25% more likely to develop AKI after adjustment for confounding variables (OR = 1.25; 95% CI 1.08-1.46). No significant association was found for hypermagnesemia and AKI (OR = 1.18; 95% CI 0.89-1.57). Kidney function recovery was similar among groups but hypermagnesemia had lower non-recovery rates. Both hypomagnesemia and hypermagnesemia were associated with 65 and 52% higher mortality risk after adjustments for confounders, respectively (HR = 1.65; 95% CI 1.32-2.06 and 1.52; 95% CI 1.01-2.29).

CONCLUSIONS

Hypomagnesemia, but not hypermagnesemia, at ICU admission was associated with AKI development. On the other hand, both hypomagnesemia and hypermagnesemia were associated with higher mortality risks.

Abnormal magnesium levels and their impact on death and acute kidney injury in critically ill children

BACKGROUND

The prevalence of magnesium imbalance in critically ill children is very high. However, its significance in the development of acute kidney injury (AKI) and mortality remains unknown.

METHODS

In this retrospective observational study from 2010 to 2018, the pediatric-specific intensive care database was analyzed. We included critically ill children aged > 3 months and those without chronic kidney disease. Patients were diagnosed with AKI, according to the Kidney Disease Improving Global Outcomes (KDIGO) study. We calculated the initial corrected magnesium levels (cMg) within 24 h and used a spline regression model to evaluate the cut-off values for cMg. We analyzed 28-day mortality and its association with AKI. The interaction between AKI and magnesium imbalance was evaluated.

RESULTS

The study included 3,669 children, of whom 105 died within 28 days, while 1,823 were diagnosed with AKI. The cut-off values for cMg were 0.72 and 0.94 mmol/L. Both hypermagnesemia and hypomagnesemia were associated with 28-day mortality (odds ratio [OR] = 2.99, 95% confidence interval [CI] = 1.89-4.71, p < 0.001; OR = 2.80, 95% CI = 1.60-4.89, p < 0.001). Hypermagnesemia was associated with AKI (OR = 1.52, 95% CI = 1.27-1.82, p < 0.001), while neither hypermagnesemia nor hypomagnesemia interacted with the AKI stage on the 28-day mortality.

CONCLUSIONS

Abnormal magnesium levels were associated with 28-day mortality in critically ill children. AKI and hypermagnesemia had a strong association. "A higher resolution version of the Graphical abstract is available as Supplementary information".

Hypermagnesaemia, but Not Hypomagnesaemia, Is a Predictor of Inpatient Mortality in Critically Ill Children with Sepsis

Objective

The effect of serum magnesium on the prognosis of children with sepsis in the pediatric intensive care unit (PICU) is unclear. This study was designed to assess the risk of inpatient mortality for children with sepsis in the PICU based on serum magnesium levels at admission.

Methods

We collected patients' clinical information from the Pediatric Intensive Care database and then performed locally weighted scatterplot smoothing (LOWESS) analysis, Kaplan–Meier analysis, and multivariate logistic regression to determine the relationship between admission serum magnesium and inpatient mortality in children with sepsis.

Results

A total of 974 critically ill children with sepsis were included, with 246 patients in the hypomagnesemia group, 666 in the normal group, and 62 in the hypermagnesemia group. The chi-square test suggested that the hypermagnesemia group had higher in-hospital mortality than the normal group (14.5% vs. 2.4%, P < 0.001). Kaplan–Meier curves revealed that the 30-day overall survival rate was lower in the hypermagnesaemia group than in the normal group (P < 0.001). The multivariate logistic regression model revealed that hypermagnesaemia was a risk factor related to inpatient mortality (odds ratio 4.22, 95% CI 1.55-11.50), while hypomagnesaemia was not a significant factor for inpatient mortality (odds ratio 0.78, 95% CI 0.26-2.32).

Conclusion

Hypermagnesaemia, but not hypomagnesaemia, is a predictor of inpatient mortality in critically ill children with sepsis.

Machine Learning Consensus Clustering Approach for Hospitalized Patients with Dysmagnesemia

BACKGROUND

The objectives of this study were to classify patients with serum magnesium derangement on hospital admission into clusters using unsupervised machine learning approach and to evaluate the mortality risks among these distinct clusters.

METHODS

Consensus cluster analysis was performed based on demographic information, principal diagnoses, comorbidities, and laboratory data in hypomagnesemia (serum magnesium ≤ 1.6 mg/dL) and hypermagnesemia cohorts (serum magnesium ≥ 2.4 mg/dL). Each cluster's key features were determined using the standardized mean difference. The associations of the clusters with hospital mortality and one-year mortality were assessed.

RESULTS

In hypomagnesemia cohort (n = 13,320), consensus cluster analysis identified three clusters. Cluster 1 patients had the highest comorbidity burden and lowest serum magnesium. Cluster 2 patients had the youngest age, lowest comorbidity burden, and highest kidney function. Cluster 3 patients had the oldest age and lowest kidney function. Cluster 1 and cluster 3 were associated with higher hospital and one-year mortality compared to cluster 2. In hypermagnesemia cohort (n = 4671), the analysis identified two clusters. Compared to cluster 1, the key features of cluster 2 included older age, higher comorbidity burden, more hospital admissions primarily due to kidney disease, more acute kidney injury, and lower kidney function. Compared to cluster 1, cluster 2 was associated with higher hospital mortality and one-year mortality.

CONCLUSION

Our cluster analysis identified clinically distinct phenotypes with differing mortality risks in hospitalized patients with dysmagnesemia. Future studies are required to assess the application of this ML consensus clustering approach to care for hospitalized patients with dysmagnesemia.

Impact of different hemodiafiltration solutions on ionemia in long-term CRRT

Critical patients with Acute Kidney Injury (AKI) requiring renal replacement therapy are in most cases eligible only for continuous modalities where the electrolyte balance control is a critical issue. The standard solutions used for hemodiafiltration, containing potassium at 2 mmol/L and no phosphorus, determines during the extended renal replacement therapy hypokalemia and hypophosphatemia. Therefore, solutions containing potassium and phosphate in physiological concentrations were formulated to avoid electrolyte imbalances and reduce ion alterations in prolonged treatments, these solutions are not routinely used in the standard clinical practice. To avoid electrolyte imbalances, we have first introduced in our practice two different solutions and then we have retrospectively analyzed the electrolyte balance upon these two solutions in order to identity the impact of these solutions on potassium and phosphate according to our clinical practice. We retrospectively analyzed 96 patients treated with Continuous Renal Replacement Therapy (CRRT) in the intensive care units (ICU) at Padua's University Hospital to evaluate the role on electrolyte balance of Phoxilium^® and Prismasol 2^® that differ in their composition and the need for electrolytes infusions. In the Phoxilium group the frequency of hypokalemia, hypophosphatemia, and the need of potassium and phosphate replacement were significantly reduced resulting in a reduction in complications, workload, and clinical risk associated with infusions of electrolytes. Our data demonstrated that the use of these two different hemodiafiltration solutions can reduce the occurrence of hypokalemia and hypophosphatemia during CRRT performing personalized treatments without the use of potassium and phosphate infusions.

Inorganic material based macrophage regulation for cancer therapy: basic concepts and recent advances

Macrophages with the M1 phenotype are a type of immune cell with exciting prospects for cancer therapy; however, when these macrophages infiltrate into tumours, many of them are induced by the tumour microenvironment to transform into the M2 type, which can enable tumour defence against external therapeutic strategies, assisting in tumour development. Macrophages have strong plasticity and functional heterogeneity, and their phenotypic transformation is complex and still poorly understood in relation to cancer therapy. Recent material advances in inorganic nanomaterials, especially inorganic elements in vivo, have accelerated the development of macrophage regulation-based cancer treatments. This review summarizes the basics of recent research on macrophage phenotype transformation and discusses the current challenges in macrophage type regulation. Then, the current achievements involving inorganic material-based macrophage regulation and the related anticancer effects of induced macrophages and their extracellular secretions are reviewed systematically. Importantly, inorganic nanomaterial-based macrophage phenotype regulation is flexible and can be adapted for different types of cancer therapies, presenting a possible novel approach for the generation of immune materials for cancer therapy.

Prognostic value of admission serum magnesium in acute myocardial infarction complicated by malignant ventricular arrhythmias

OBJECTIVES

Although electrolyte abnormalities are related to worse clinical outcomes in patients with acute myocardial infarction (AMI), little is known about the association between admission serum magnesium level and adverse events in AMI patients complicated by out-of-hospital cardiac arrest presenting with malignant ventricular arrhythmias (OHCA-MVA). We investigated the prognostic value of serum magnesium level on admission in these patients.

METHODS

We retrospectively analyzed the data of 165 consecutive reperfused AMI patients complicated with OHCA-MVA between April 2007 and February 2020 in our university hospital. Serum magnesium concentration was measured on admission. The primary outcome was in-hospital death.

RESULTS

Fifty-four patients (33%) died during hospitalization. Higher serum magnesium level was significantly related to in-hospital death (Fine & Gray's test; p < 0.001). In multivariable logistic regression analyses, serum magnesium level on admission was independently associated with in-hospital death (hazard ratio 2.68, 95% confidence interval 1.24-5.80) even after adjustment for covariates. Furthermore, the incidences of cardiogenic shock necessitating an intra-aortic balloon pump (p = 0.005) or extracorporeal membrane oxygenation (p < 0.001), tracheal intubation (p < 0.001) and persistent vegetative state (p = 0.002) were significantly higher in patients with higher serum magnesium level than in those with lower serum magnesium level.

CONCLUSIONS

In reperfused AMI patients complicated by OHCA-MVA, admission serum magnesium level might be a potential surrogate marker for predicting in-hospital death.

Regulation of extracellular bioactive cations in bone tissue microenvironment induces favorable osteoimmune conditions to accelerate in situ bone regeneration

The design of orthopedic biomaterials has gradually shifted from “immune-friendly” to “immunomodulatory,” in which the biomaterials are able to modulate the inflammatory response via macrophage polarization in a local immune microenvironment that favors osteogenesis and implant-to-bone osseointegration. Despite the well-known effects of bioactive metallic ions on osteogenesis, how extracellular metallic ions manipulate immune cells in bone tissue microenvironments toward osteogenesis and subsequent bone formation has rarely been studied. Herein, we investigate the osteoimmunomodulatory effect of an extracellular bioactive cation (Mg²⁺) in the bone tissue microenvironment using custom-made poly lactic-co-glycolic acid (PLGA)/MgO-alendronate microspheres that endow controllable release of magnesium ions. The results suggest that the Mg²⁺-controlled tissue microenvironment can effectively induce macrophage polarization from the M0 to M2 phenotype via the enhancement of anti-inflammatory (IL-10) and pro-osteogenic (BMP-2 and TGF-β1) cytokines production. It also generates a favorable osteoimmune microenvironment that facilitates the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. The in vivo results further verify that a large amount of bony tissue, with comparable bone mineral density and mechanical properties, has been generated at an early post-surgical stage in rat intramedullary bone defect models. This study demonstrates that the concept of in situ immunomodulated osteogenesis can be realized in a controlled magnesium tissue microenvironment.

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Controlled release of Mg²⁺ was achieved by the microfluidic electrosprayed PLGA/MgO-alendronate microspheres.

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PLGA/MgO-alendronate microspheres with satisfied osteoimmunomodulatory properties accelerated bone regeneration in vivo.

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Extracellular Mg²⁺ induced macrophage switch to M2 phenotype with enhanced expressions of IL-10, BMP-2 and TGF-β1.

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Osteoimmune microenvironment favourably upregulated the osteogenic expressions of BMSCs.

In vitro activity of omadacycline and levofloxacin against Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus in human urine supplemented with calcium and magnesium

BACKGROUND

Omadacycline, an aminomethylcycline, was approved in 2018 for the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. In a Phase Ib study, around 34% of the absorbed dose of omadacycline was shown to be excreted in urine-an important property for urinary tract infection (UTI) treatment. Therefore, omadacycline has been studied in two Phase II trials for the treatment of uncomplicated UTIs and acute pyelonephritis. The activity of omadacycline against UTI pathogens in human urine is important to understand in this context.

OBJECTIVES

To study the in vitro activity of omadacycline against UTI pathogens in human urine supplemented with calcium and magnesium.

METHODS

Omadacycline activity was compared with that of levofloxacin against the urinary pathogens Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus in standard medium, pooled normal human urine and neutral pH-adjusted pooled normal human urine spiked with calcium or magnesium at concentrations consistent with hypercalcaemia and hypermagnesaemia.

RESULTS

The activities of omadacycline and levofloxacin against these urinary pathogens were lower in urine relative to standard medium; addition of Mg2+ to broth and urine had a further negative impact on omadacycline activity, whereas the addition of Ca2+ had less of an impact. Levofloxacin activity was not substantially reduced in either broth or urine by the addition of divalent cations.

CONCLUSIONS

The activity of omadacycline against UTI organisms was lower in urine relative to standard medium and was negatively impacted by magnesium. Omadacycline displayed slightly reduced activity when excess calcium was present, but, overall, the differences were ≤2-fold. These observations should be considered along with the pharmacokinetics of the agent for clinical context.

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.

In vitro immunomodulation of magnesium on monocytic cell toward anti-inflammatory macrophages

Biodegradable magnesium (Mg) has shown great potential advantages over current bone fixation devices and vascular scaffold technologies; however, there are few reports on the immunomodulation of corrosive Mg products, the micron-sized Mg particles (MgMPs). Human monocytic leukemia cell line THP-1 was set as the in vitro cell model to estimate the immunomodulation of MgMPs on cell proliferation, apoptosis, polarization and inflammatory reaction. Our results indicated high-concentration of Mg²⁺ demoted the proliferation of the THP-1 cells and, especially, THP-1-derived macrophages, which was a potential factor that could affect cell function, but meanwhile, cell apoptosis was almost not affected by Mg²⁺. In particular, the inflammation regulatory effects of MgMPs were investigated. Macrophages exposed to Mg²⁺ exhibited down-regulated expressions of M1 subtype markers and secretions of pro-inflammatory cytokines, up-regulated expression of M2 subtype marker and secretion of anti-inflammatory cytokine. These results indicated Mg²⁺ could convert macrophages from M0 to M2 phenotype, and the bioeffects of MgMPs on human inflammatory cells were most likely due to the Mg²⁺-induced NF-κB activation reduction. Together, our results proved Mg²⁺ could be used as a new anti-inflammatory agent to suppress inflammation in clinical applications, which may provide new ideas for studying the immunomodulation of Mg-based implants on human immune system.

High- and low-inpatients' serum magnesium levels are associated with in-hospital mortality in elderly patients: a neglected marker?

BACKGROUND

Altered serum magnesium (Mg) level in the human body has been hypothesized to have a role in the prediction of hospitalization and mortality; however, the reported outcomes are not conclusive.

AIMS

The present study aimed to analyze the relationship between serum Mg and in-hospital mortality (IHM) in patients admitted to the medical ward of two hospitals in the Veneto region (Italy).

METHODS

Patients > 18 years hospitalized in the medical wards of the hospitals of Vittorio Veneto and Conegliano, Italy (from January 12, 2011, through December 27, 2016) with at least one measurement of serum Mg were included in the study. A logistic regression model was used to assess the unadjusted and adjusted (by age, gender, Charlson Comorbidity index, discharge diagnosis' class) association of serum Mg and IHM.

RESULTS

In total 5024 patients were analyzed, corresponding to 6980 total admissions. The unadjusted analysis showed that IHM risk was significantly higher with 0.2 mg/dl incremental serum Mg level change from 2.4 mg/dl to 2.6, (OR 1.71 95% CI 1.55-1.89) and with 0.2 mg/dl change from serum Mg level of 1.4 mg/dl to 1.2 mg/dl, (OR 1.28 95% CI 1.17-1.40). Such results were confirmed at adjusted analysis.

DISCUSSION

Present findings have relevant implications for the clinical management of patients suffering from medical conditions, highlighting the need for analyzing Mg concentration carefully.

CONCLUSIONS

Serum Mg levels seem to be a good predictor of IHM.

Effects of magnesium, phosphate and zinc supplementation in ICU patients-Protocol for a systematic review

BACKGROUND

Depletion of the trace elements magnesium, phosphate and zinc is common in patients admitted to the intensive care unit (ICU). Observational studies have suggested worse outcome in patients with hypomagnesaemia, hypophosphataemia or hypozincaemia, but also inverse associations with worse outcome with too high serum levels. However, it is unclear whether data from randomised clinical trials (RCTs) confirm this. Accordingly, we plan to assess the balance between benefits and harms of supplementation as compared with placebo or no supplementation in adult ICU patients.

METHODS

We will conduct a systematic review of RCTs with meta-analysis and trial sequential analysis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions, the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement and the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach. We will assess the effects of any supplementation with magnesium, phosphate or zinc vs. placebo or no treatment in adult ICU patients. We will systematically search the Cochrane CENTRAL, Embase, PubMed, and for unpublished trials: ClinicalTrials.gov, the EU clinical Trials Register and the WHO International Clinical Trials Registry Platform. The primary outcomes will be days alive without mechanical ventilation and overall mortality. Secondary outcomes include use for mechanical ventilation, tachy-arrhythmias, use of vasopressors, length of hospital stay and use of renal replacement therapy.

DISCUSSION

The benefits and harms of supplementation therapy with magnesium, phosphate and zinc in general ICU patients are unknown. This outlined systematic review will provide data on the evidence, on which future recommendations for supplementation may be founded.

Electrolyte imbalances in an unselected population in an emergency department: A retrospective cohort study

BACKGROUND

Although electrolyte imbalances (EIs) are common in the emergency department (ED), few studies have examined the occurrence of such conditions in an unselected population.

OBJECTIVES

To investigate the frequency of EI among adult patients who present to the ED, with regards to type and severity, and the association with age and sex of the patient, hospital length of stay (LOS), readmission, and mortality.

METHODS

A retrospective cohort study. All patients ≥18 years referred for any reason to the ED between January 1, 2010, and December 31, 2015, who had measured blood electrolytes were included. In total, 62 991 visits involving 31 966 patients were registered.

RESULTS

EIs were mostly mild, and the most common EI was hyponatremia (glucose-corrected) (24.6%). Patients with increasing severity of EI had longer LOS compared with patients with normal electrolyte measurements. Among all admitted patients, there were 12928 (20.5%) readmissions within 30 days from discharge during the study period. Hyponatremia (glucose-corrected) was associated with readmission, with an adjusted odds ratio (OR) of 1.25 (95% CI, 1.18-1.32). Hypomagnesemia and hypocalcemia (albumin-corrected) were also associated with readmission, with ORs of 1.25 (95% CI, 1.07-1.45) and 1.22 (95% CI, 1.02-1.46), respectively. Dysnatremia, dyskalemia, hypercalcemia, hypermagnesemia, and hyperphosphatemia were associated with increased in-hospital mortality, whereas all EIs except hypophosphatemia were associated with increased 30-day and 1-year mortality.

CONCLUSIONS

EIs were common and increasing severity of EIs was associated with longer LOS and increased in-hospital, 30-days and 1-year mortality. EI monitoring is crucial for newly admitted patients, and up-to-date training in EI diagnosis and treatment is essential for ED physicians.

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.

Analysis of hypo- and hypermagnesemia in an intensive care unit cohort

INTRODUCTION

The aim of this study was to evaluate if magnesium deviations correlate with higher 180 day overall mortality or increased morbidity, compared to controls.

METHODS

We conducted a retrospective study on 5369 patients with 22,003 magnesium values treated at the Adult Intensive Care Unit at Skåne University Hospital, Lund, Sweden during 2006-2014. The patients were retrospectively divided into a control group with only normal magnesium values 0.7-1.0 mmol/l, and three study groups; hypomagnesemic; Mg²⁺ < 0.7 mmol/l, hypermagnesemic; Mg²⁺ > 1.0 mmol/l and an unstable mixed group showing both hypo/hypermagnesemia. Gender, age, disease severity represented by maximum organ system SOFA score, renal SOFA score, lowest potassium value and diagnoses classes were included in a Cox hazard model in order to adjust for confounding factors, with time to death in the first 180 days from the ICU admission as outcome.

RESULTS

The hypermagnesemic study group and the mixed group showed increased hazard ratios for mortality; 1.4 (CI 98.3% 1.2, 1.6, P < 0.0001) and 2.1 (CI 98.3% 1.2, 2.8, P < 0.0001) respectively, compared to controls, while the hypomagnesemic group did not reach significance. In addition, patients in the hypermagnesemic and the mixed groups are older, more ill with significantly higher EMR and SOFA scores and show significantly longer ventilator times and ICU stays, compared to controls.

CONCLUSIONS

Patients with magnesium deviations are more ill compared to patients with explicitly normal magnesium values throughout the ICU stay. Cox analysis suggests that the magnesium deviation itself might have an impact on mortality.

Magnesium Replacement to Protect Cardiovascular and Kidney Damage? Lack of Prospective Clinical Trials

Patients with advanced chronic kidney disease exhibit an increase in cardiovascular mortality. Recent works have shown that low levels of magnesium are associated with increased cardiovascular and all-cause mortality in hemodialysis patients. Epidemiological studies suggest an influence of low levels of magnesium on the occurrence of cardiovascular disease, which is also observed in the normal population. Magnesium is involved in critical cellular events such as apoptosis and oxidative stress. It also participates in a number of enzymatic reactions. In animal models of uremia, dietary supplementation of magnesium reduces vascular calcifications and mortality; in vitro, an increase of magnesium concentration decreases osteogenic transdifferentiation of vascular smooth muscle cells. Therefore, it may be appropriate to evaluate whether magnesium replacement should be administered in an attempt to reduce vascular damage and mortality in the uremic population In the present manuscript, we will review the magnesium homeostasis, the involvement of magnesium in enzymatic reactions, apoptosis and oxidative stress and the clinical association between magnesium and cardiovascular disease in the general population and in the context of chronic kidney disease. We will also analyze the role of magnesium on kidney function. Finally, the experimental evidence of the beneficial effects of magnesium replacement in chronic kidney disease will be thoroughly described.

The characteristics of patients with hypermagnesemia who underwent emergency hemodialysis

Aim

This study aimed to clarify the characteristics of patients who presented with severe hypermagnesemia and subsequently underwent emergency hemodialysis.

Methods

We investigated the age, gender, complications, clinical symptoms, causal drugs, electrocardiogram findings, and laboratory data of 15 patients.

Results

Magnesium oxide had been administered in all cases and 14 patients were over 65 years old. The male : female ratio was 6:9. Chief complaints included a disturbance of consciousness, hypotension, bradycardia, and respiratory failure. The median serum magnesium value before hemodialysis was 6.0 (3.7–18.6) mg/dL. The daily dosage of magnesium oxide was ≤ 2.0 g in 12 cases. The median serum creatinine value before hemodialysis was 5.39 (0.54–10.29) mg/dL. However, in two cases, the creatinine value was not elevated. Complications of acute kidney injury exacerbated the hypermagnesemia in nine cases.

Conclusions

We recommend that the serum magnesium value should be measured in older patients who are taking magnesium oxide and are showing signs and symptoms of a disturbance of consciousness, hypotension, bradycardia, and respiratory failure of an uncertain etiology, even if the serum creatinine value is not elevated or the dosage of magnesium oxide is within recommended levels.

Effects of Canagliflozin on Serum Magnesium in Patients With Type 2 Diabetes Mellitus: A Post Hoc Analysis of Randomized Controlled Trials

INTRODUCTION

The objective of this study was to evaluate the effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on serum magnesium in hypomagnesemic patients with type 2 diabetes.

METHODS

This post hoc analysis was based on pooled data from four placebo-controlled studies of canagliflozin (N = 2313). The proportion of patients with baseline serum magnesium <0.74 mmol/L who achieved serum magnesium ≥0.74 mmol/L at week 26 was evaluated.

RESULTS

At week 26, canagliflozin 100 and 300 mg increased serum magnesium versus placebo in patients with baseline serum magnesium <0.74 mmol/L (17.0% and 19.0% vs 3.9%) and ≥0.74 mmol/L (4.9% and 7.0% vs -1.4%). More patients with baseline serum magnesium <0.74 mmol/L had serum magnesium ≥0.74 mmol/L at week 26 with canagliflozin 100 and 300 mg versus placebo (74.1% and 80.6% vs 28.8%).

CONCLUSIONS

Canagliflozin was associated with normalization of serum magnesium in hypomagnesemic patients with type 2 diabetes, potentially leading to improved cardiometabolic outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifiers, NCT01081834, NCT01106677, NCT01106625, NCT01106690.

In vitro and in vivo responses of macrophages to magnesium-doped titanium

Modulating immune response to biomaterials through changing macrophage polarization has been proven to be a promising strategy to elicit beneficial outcomes in tissue repair. The objective of this study was to evaluate the response of macrophage polarization to titanium doped with magnesium (0.1~0.35%), which was prepared through the magnesium plasma immersion ion implantation (Mg PIII) technique. The M1/M2 polarization profile of macrophages was investigated using a murine cell line RAW 264.7 in vitro and a murine air pouch model in vivo. Our results demonstrated that the Mg PIII-treated titanium induced a higher percentage of M2 macrophages and higher concentrations of the anti-inflammatory cytokines interleukin (IL)-4 and IL-10. Genes encoding two growth factors, bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF) were up-regulated, thus indicating the ability of the M2 phenotype to promote wound healing. The nuclear factor κB (NF-κB) signalling pathway was down-regulated. In vivo the Mg PIII -treated titanium elicited a similar effect on macrophage polarization and induced thinner fibrous capsule formation and a decrease in infiltrated cells. These results indicate that Mg PIII treatment has the immunomodulatory potential to elicit the pro-healing M2-polarized macrophage phenotype, thus providing new insight into the development of immunomodulatory biomaterials.

Association of Serum Magnesium on Mortality in Patients Admitted to the Intensive Cardiac Care Unit

BACKGROUND

Although electrolyte disturbances may affect cardiac action potential, little is known about the association between serum magnesium and corrected QT (QTc) interval as well as clinical outcomes.

METHODS

A consecutive 8498 patients admitted to the Mayo Clinic Hospital-Rochester cardiac care unit (CCU) from January 1, 2004 through December 31, 2013 with 2 or more documented serum magnesium levels, were studied to test the hypothesis that serum magnesium levels are associated with in-hospital mortality, sudden cardiac death, and QTc interval.

RESULTS

Patients were 67 ± 15 years; 62.2% were male. The primary diagnoses for CCU admissions were acute myocardial infarction (50.7%) and acute decompensated heart failure (42.5%), respectively. Patients with higher magnesium levels were older, more likely male, and had lower glomerular filtration rates. After multivariate analyses adjusted for clinical characteristics including kidney disease and serum potassium, admission serum magnesium levels were not associated with QTc interval or sudden cardiac death. However, the admission magnesium levels ≥2.4 mg/dL were independently associated with an increase in mortality when compared with the reference level (2.0 to <2.2 mg/dL), having an adjusted odds ratio of 1.80 and a 95% confidence interval of 1.25-2.59. The sensitivity analysis examining the association between postadmission magnesium and analysis that excluded patients with kidney failure and those with abnormal serum potassium yielded similar results.

CONCLUSION

This retrospective study unexpectedly observed no association between serum magnesium levels and QTc interval or sudden cardiac death. However, serum magnesium ≥2.4 mg/dL was an independent predictor of increased hospital morality among CCU patients.

Elevated serum magnesium associated with SGLT2 inhibitor use in type 2 diabetes patients: a meta-analysis of randomised controlled trials

AIMS/HYPOTHESIS

By analysing available evidence from randomised controlled trials (RCTs), we aimed to examine whether and to what extent sodium-glucose cotransporter 2 (SGLT2) inhibitors affect serum electrolyte levels in type 2 diabetes patients.

METHODS

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and ClinicalTrials.gov up to 24 May 2016 for published RCTs of SGLT2 inhibitors that reported changes in serum electrolyte levels. Weighted mean differences (WMD) between each SGLT2 inhibitor and placebo were calculated using a random-effects model. Dose-dependent relationships for each SGLT2 inhibitor were evaluated using meta-regression analysis.

RESULTS

Eighteen eligible RCTs, including 15,309 patients and four SGLT2 inhibitors (canagliflozin, dapagliflozin, empagliflozin and ipragliflozin) were evaluated. In patients without chronic kidney disease, each SGLT2 inhibitor significantly increased serum magnesium levels compared with placebo (canagliflozin: WMD 0.06 mmol/l for 100 mg and 0.09 mmol/l for 300 mg; dapagliflozin: WMD 0.1 mmol/l for 10 mg; empagliflozin: WMD 0.04 mmol/l for 10 mg and 0.07 mmol/l for 25 mg; and ipragliflozin: WMD 0.05 mmol/l for 50 mg). Canagliflozin increased serum magnesium in a linear dose-dependent manner (p = 0.10). Serum phosphate was significantly increased by dapagliflozin. Serum sodium appeared to significantly differ by SGLT2 inhibitor type. No significant changes in serum calcium and potassium were observed. Findings were robust after including trials involving patients with chronic kidney disease.

CONCLUSIONS/INTERPRETATION

SGLT2 inhibitors marginally increased serum magnesium levels in type 2 diabetes patients indicating a drug class effect. Further investigations are required to examine the clinical significance of elevated magnesium levels in individuals with type 2 diabetes.

The combined use of three widely available biochemical markers as predictor of organ failure in critically ill patients

BACKGROUND

We hypothesized that lactate dehydrogenase, LDH/albumin ratio in combination with or without magnesium (Mg(2+)) could predict organ failure in critically ill adult patients. The aim of this study was to describe a new risk index for organ failure or mortality in critically ill patients based on a combination of these routinely available biochemical plasma biomarkers.

METHODS

Patients ≥ 18 years admitted to the intensive care unit (ICU) were screened. Albumin and LDH were analyzed at the time of admission to ICU (n = 347). Organ failure assessed with 'Sequential Organ Failure Assessment' (SOFA) score was used, and 30-day mortality was recorded. The predictive value of the test was calculated using the areas under the receiving operating characteristic (ROC) curve.

RESULTS

The LDH/albumin ratio was higher in patients who developed organ failure as compared to those who did not (p < 0.001). The areas under the ROC curve were 0.77 both for prediction of multiple organ failure and for 30-day mortality. In a subgroup of patients (n = 183) admitted to ICU from the emergency department, the predictive values were 0.86 and 0.80, respectively.

CONCLUSION

The LDH/albumin ratio at ICU admission was associated with the development of multiple organ failure and 30-day mortality in this prospective study. The clinical value of this biomarker as a predictor of organ failure in critically ill patients is yet to be defined.