Reduced intracellular Mg concentrations in patients with acute asthma

Low Serum Levels of Zinc, Selenium, and Vitamin D3 Are Biomarkers of Airway Inflammation and Poor Asthma Control: A Two-Centre Study

Background Asthma is a chronic inflammatory disease with its control being affected by underlying oxidative stress. Trace elements, along with vitamin D3, play an important role in immune alterations leading to an imbalance of Th1/Th2 helper cells. However, their role in asthma pathogenesis and control is inconsistent and inconclusive. The objective of our study was to assess levels of serum trace elements like zinc, copper, selenium, iron, magnesium, vitamin D3 levels, IgE, and HsCRP in asthmatic children, compare with healthy controls, and assess their association with the level of asthma control. Methods A cross-sectional study was conducted from 2019 to 2021 enrolling 100 asthmatic children and 75 healthy controls. The level of asthma control was assessed as uncontrolled, partly controlled, and controlled asthma as per GINA Guidelines. Mean and standard deviation were calculated for each element and mean differences between groups were analyzed by student t-test. A p-value of <0.05 was considered significant. Results The mean age was 8.75±2.89 yrs in cases and 9.04±2.79 in controls. A total of 57.6% of cases had atopic comorbidities. The mean serum zinc levels were 51±12.8 mg/dl, which was very low in asthmatic children as compared to 60±18.2mg/dl (p-value 0.0002) in healthy controls. Serum selenium was 13±3 µg/dl in asthmatics vs. 15±4 µg/dl (p-value 0.0002) in healthy controls. Serum copper was 115.2±21.92µg/dl vs. 125.3±31.99µg/dl (p-value 0.015), Serum vitamin D3 levels were 13.07±7.82ng/ml vs. 17.82±14.62 ng/ml(p-value 0.006) in both groups, respectively. SIgE and HsCRP were high in asthmatic children suggestive of eosinophilic inflammation. Serum zinc was 49±5.45 mg/dl in the uncontrolled group, 53±6.1 in the partly controlled, and 58±8.0 in the well-controlled group (p<0.0001). Serum selenium was 10± 3.0 µg/dl in the uncontrolled group vs. 13± 2.0 and 14± 2.0 µg/dl in the partly controlled and well-controlled groups, respectively (p-value <0.0001). Vitamin D3 was significantly low (9.32±5.95ng/dl) in the uncontrolled group vs. 12.99±4.97 and 13.40±5.92 ng/dl(p<0.005) in the partly controlled and well-controlled groups respectively. Vitamin D3 showed a strong positive correlation with zinc (r=0.4,p< 0.0001) and a negative correlation with inflammatory markers like SIgE and HsCRP. Conclusion Children with asthma had low zinc, selenium, and vitamin D3 levels, and were associated with airway inflammation and poor asthma control.

Sex Difference Between Trace Elements and Pulmonary Functions in Children

It has been defined that deficiency of trace elements plays an important role in the progression of asthma. However, the relationship between blood zinc (Zn), selenium (Se), and magnesium (Mg) and pulmonary functions in children remains to be clarified. A cross-sectional study was conducted in Wuxi, China, and a total of 202 healthy children were recruited. The forced vital capacity volume (FVC) and forced expiratory volume in the 1 s (FEV1) were measured. Blood samples were collected, and the levels of blood zinc, selenium, and magnesium were measured by inductively coupled plasma mass spectrometry (ICP-MS). Meanwhile, the concentrations of serum total IgE was also determined. The associations between trace elements and pulmonary functions were analyzed by multiple linear regression models. After stratified by sex, there was a positive association between blood Zn and pulmonary functions in boys. In addition, blood Zn was also negatively associated with serum total IgE concentrations in boys, but not in girls after adjusting for potential confounders. Our findings indicated that zinc deficiency was significantly related to children's pulmonary functions and that screening of trace elements may be a potential solution to decrease the risks of asthma in children.

Association between trace elements levels and asthma susceptibility

BACKGROUND

It is well-documented that the dysregulation of trace elements may be involved in the pathogenesis of asthma. However, the precise changes of trace elements levels in asthma cases remain elusive. We established whether trace elements levels were associated with asthma susceptibility by pooling case-control studies.

METHODS

34 studies were included. We extracted the standard mean differences (SMDs) and corresponding 95% confidence intervals (CIs). A pooled-analysis was performed.

RESULTS

No marked difference (95% CI: -1.437-0.218, p = 0.149) of Se level between asthma and controls. Significant difference (95% CI: 0.112-1.032, p = 0.015; 95% CI: 0.376-1.331, p < 10^-4) of Cu level between asthma and controls was noted among overall populations and Asians. No marked difference of Zn level between asthma and controls was observed among overall populations, Asians, Caucasians and Africans. Significant difference (95% CI: -0.567 to -0.238, p < 10^-4) of Mg level between asthma and controls was noted among Asians. Marked difference (95% CI: 0.258-2.864, p = 0.019; 95% CI: 0.270-3.282, p = 0.021) of Fe level between asthma and controls was noted among overall populations and Asians. Age had no impact on the pooled SMDs of Se, Cu, Zn, Mg and Fe between asthma and controls. Sensitivity analyses did not change the overall results. No publication bias was noted for overall populations.

CONCLUSIONS

Alterations of Cu, Mg and Fe levels may be a biomarker of asthma risk among specific populations. Further studies should be performed to clarify the strength of these elements in asthma.

Clinical pharmacokinetics of magnesium sulfate in the treatment of children with severe acute asthma

PURPOSE

Intravenous (IV) magnesium sulfate (MgSO₄) is used as adjunct therapy to treat acute asthma exacerbations. Despite its clinical use, there is a limited understanding of the disposition of magnesium in children.

METHODS

To explore the pharmacokinetics (PK) of IV MgSO₄ in this population, we collected retrospective data from 54 children who received IV MgSO₄ for treatment of an acute asthma exacerbation at Primary Children's Hospital in Salt Lake City, UT. These data were analyzed using population PK modeling techniques in NONMEM® to determine sources of variability affecting the disposition of magnesium, as well as to predict the dose of IV MgSO₄ needed to achieve clinical benefit.

RESULTS

The covariate analysis found that only weight was a significant predictor of magnesium concentrations in children. Estimated model parameters suggested that magnesium exhibits a short serum half-life (2.7 h) in children. The average endogenous magnesium concentration (prior to administration of IV MgSO₄) was estimated to be 21 mg/L. Simulated data suggested that doses between 50 and 75 mg/kg are required to achieve concentration-time profiles within a hypothesized target therapeutic range between 25 and 40 mg/L.

CONCLUSIONS

These results provide new insight into the disposition of IV MgSO₄ in children and provide dosing guidelines for future prospective studies of IV MgSO₄ in children with acute asthma.

Optimizing the use of intravenous magnesium sulfate for acute asthma treatment in children

BACKGROUND

Asthma is the most common pediatric chronic disease and currently affects 7.1 million children in the United States. Many children experience acute asthma exacerbations. Many children also require hospitalization despite treatment in an emergency department with current standard therapy (corticosteroids, albuterol, and ipratropium). These hospitalizations may be avoided if effective adjunctive therapies can be developed to adequately treat severe exacerbations.

METHODS

Publications were searched in the PubMed database using the following keywords: magnesium AND asthma AND children AND randomized controlled trial. A total of 30 publications were returned. References of relevant articles were also screened. We included publications of controlled randomized trials where intravenous magnesium sulfate was studied in children (age < 18 years) with acute asthma (n = 7). We excluded studies in adults or trials with other formulations of magnesium (e.g., nebulized).

RESULTS

Previous studies have demonstrated that intravenous magnesium sulfate (IV MgSO₄ ) significantly improves respiratory function and reduces hospitalization rate in children with moderate to severe asthma exacerbations. Current dosing regimens involve a short infusion of 25-75 mg/kg over 20 min (maximum 2-2.5 g/dose), though no studies have directly compared dosages for relative efficacy. Several studies suggest utilizing a peak plasma concentration of magnesium higher than 4 mg/dL as a surrogate of efficacy. This review summarizes the literature regarding the use of IV MgSO₄ for the treatment of pediatric acute asthma.

CONCLUSIONS

We suggest that optimized dosing regimens could be developed using a linked pharmacokinetic-pharmacodynamic modeling and simulation approach. We propose the factors that should be considered in future clinical trial design in order to better understand the use of IV MgSO₄ in pediatric acute asthma. Pediatr Pulmonol. 2016;51:1414-1421. © 2016 Wiley Periodicals, Inc.

High-Dose Magnesium Sulfate Infusion for Severe Asthma in the Emergency Department: Efficacy Study

OBJECTIVE

To assess the efficacy of a high-dose prolonged magnesium sulfate infusion in patients with severe, noninfectious-mediated asthma.

DESIGN

Prospective, randomized, open-label study.

SETTING

Twenty-nine-bed pediatric emergency department located in a children's hospital in Asuncion, Paraguay.

PATIENTS

All patients of 6-16 years old who failed to improve after 2 hours of standard therapy for asthma.

INTERVENTIONS

Subjects were randomized to receive magnesium sulfate, 50 mg/kg over 1 hour (bolus) or high-dose prolonged magnesium sulfate infusion of 50 mg/kg/hr for 4 hours (max, 8.000 mg/4 hr). Patients were monitored for cardiorespiratory complications.

MEASUREMENTS AND MAIN RESULTS

Asthma severity was assessed via asthma scores and peak expiratory flow rates at 0-2-6 hours. The primary outcome was discharge to home at 24 hours. An analysis of the hospital length of stay and costs was a secondary outcome. Thirty-eight patients were enrolled, 19 in each group. The groups were of similar ages, past medical history of asthma, asthma score, and peak expiratory flow rate. There was a significant difference in the patients discharged at 24 hours: 47% in high-dose prolonged magnesium sulfate infusion (9/19) versus 10% (2/21) in the bolus group (p = 0.032) with an absolute risk reduction 37% (95% CI, 10-63) and a number needed to treat of 2.7 (95% CI, 1.6-9.5) to facilitate a discharge at or before 24 hours. The length of stay was shorter in the high-dose prolonged magnesium sulfate infusion group (mean ± SD in hr: high-dose prolonged magnesium sulfate infusion, 34.13 ± 19.54; bolus, 48.05 ± 18.72; p = 0.013; 95% CI, 1.3-26.5). The cost per patient in the high-dose prolonged magnesium sulfate infusion group was one third lower than the bolus group (mean ± SD: high-dose prolonged magnesium sulfate infusion, $603.16 ± 338.47; bolus, $834.37 ± 306.73; p < 0.016). There were no interventions or discontinuations of magnesium sulfate due to adverse events.

CONCLUSIONS

The early utilization of high-dose prolonged magnesium sulfate infusion (50 mg/kg/hr/4 hr), for non-infectious mediated asthma, expedites discharges from the emergency department with significant reduction in healthcare cost.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

The use of intravenous and inhaled magnesium sulphate in management of children with bronchial asthma

BACKGROUND

Asthma is the most common chronic disease of childhood and the leading cause of childhood morbidity. When uncontrolled, asthma can place significant limits on daily life, and is sometimes fatal. The use of magnesium sulphate (MgSO4) is one of numerous treatment options available during acute severe asthma in children. The efficacy of intravenous, or inhaled MgSO4 has been demonstrated, while little is known about the actual clinical use of either intravenous (IV) or inhaled MgSO4.

OBJECTIVE

To assess the effectiveness of intravenous (IV) and/or inhaled MgSO4 on hospital admissions and pulmonary function in children with asthma. This systematic review assessed the best available evidence for the use of either intravenous or inhaled MgSO4 in children with acute asthma. Magnesium deficiency is a common electrolyte disorder in children with acute severe asthma. Several authors reported that IV magnesium was effective in the treatment of moderate to acute asthma in children but evidence for nebulised magnesium was insufficient. In addition, it is used in severe, progressed cases to prevent respiratory failure and/or admission to the intensive care unit. It has bronchodilating and anti-inflammatory effects and modulates ion transport and influences intracellular calcium concentration. Intravenous MgSO4 therapy helps in achieving earlier improvement in clinical signs and symptoms of asthma, e.g. respiratory function and significantly reduced hospital admission, in children with acute severe asthma. The role of nebulised MgSO4 in asthmatic children requires further investigation.

CONCLUSION

According to the previous studies, the author recommends the use of intravenous MgSO4 as a safe and effective adjunct to conventional bronchodilator therapy in acute severe asthma in children.

High-dose magnesium sulfate infusion protocol for status asthmaticus: a safety and pharmacokinetics cohort study

PURPOSE

To assess the safety and pharmacokinetics of high-dose magnesium sulfate (MgSO(4)) infusion in pediatric patients with status asthmaticus.

METHODS

A prospective cohort study within a 20-bed pediatric intensive care unit in an academic community hospital. Patients 2-18 years of age admitted with status asthmaticus between 10/2009 and 8/2010 were included in the study. All patients received standard therapy for asthma, while the treatment group received an intravenous magnesium sulfate bolus of 50-75 mg/kg (0.2-0.3 mmol/kg) followed by 40 mg/kg/h (0.16 mmol/kg/h) for 4 h. Patients were monitored for cardiorespiratory complications. The treatment group underwent four blood draws to assess pharmacokinetic parameters.

RESULTS

Nineteen patients were in the treatment group and 38 patients in the control group after exclusion criteria and consenting were completed. No clinically significant differences were found between groups. There were no interventions or discontinuations of MgSO(4) due to adverse events. In the treatment group, three patients had mild infusion-related reactions. Heart rate and respiratory rate were statistically significantly lower in the magnesium treatment group.

CONCLUSIONS

The continuous infusions of MgSO(4) were safe at the studied doses and maintained serum magnesium (SrMg) and ionized magnesium levels similar to levels required to produce smooth muscle relaxation in other clinical settings. Further studies are needed to investigate the efficacy of high-dose continuous MgSO(4) infusion as an adjunctive treatment for severe asthma treatment and determine the SrMg level required to maintain airway smooth muscle relaxation.

Suboptimal magnesium status in the United States: are the health consequences underestimated?

In comparison with calcium, magnesium is an "orphan nutrient" that has been studied considerably less heavily. Low magnesium intakes and blood levels have been associated with type 2 diabetes, metabolic syndrome, elevated C-reactive protein, hypertension, atherosclerotic vascular disease, sudden cardiac death, osteoporosis, migraine headache, asthma, and colon cancer. Almost half (48%) of the US population consumed less than the required amount of magnesium from food in 2005-2006, and the figure was down from 56% in 2001-2002. Surveys conducted over 30 years indicate rising calcium-to-magnesium food-intake ratios among adults and the elderly in the United States, excluding intake from supplements, which favor calcium over magnesium. The prevalence and incidence of type 2 diabetes in the United States increased sharply between 1994 and 2001 as the ratio of calcium-to-magnesium intake from food rose from <3.0 to >3.0. Dietary Reference Intakes determined by balance studies may be misleading if subjects have chronic latent magnesium deficiency but are assumed to be healthy. Cellular magnesium deficit, perhaps involving TRPM6/7 channels, elicits calcium-activated inflammatory cascades independent of injury or pathogens. Refining the magnesium requirements and understanding how low magnesium status and rising calcium-to-magnesium ratios influence the incidence of type 2 diabetes, metabolic syndrome, osteoporosis, and other inflammation-related disorders are research priorities.

Magnesium sulfate for acute asthma in adults: a systematic literature review

Magnesium sulfate (MgSO(4)) has been considered as an adjunct therapy for severe and life-threatening asthma exacerbation. The literature search was performed using MEDLINE, EMBASE, Cochrane Library and Google Scholar to summarize the current state of knowledge regarding magnesium therapy in acute exacerbation of adult asthma. A total of 16 trials and 4 meta-analyses were identified. As results, intravenous MgSO(4) was beneficial in severe exacerbation, but evidence for nebulized magnesium was insufficient. However, larger trials are required to draw confirmative conclusions on the efficacy. Regarding the safety concern, the risk of major toxicity appears to be very low at usual doses described in the literature. Additionally, results from 4 surveys were examined on the gaps between knowledge and practice, and on the barrier to the use of MgSO(4) at emergency departments. This literature review summarized the up-to-date evidence on the issues regarding the use of MgSO(4) for acute asthma. We expect more studies to be conducted for evidence making in the Asian-Pacific regions.

Influence of therapy with metformin on the concentration of certain divalent cations in patients with non-insulin-dependent diabetes mellitus

Research was performed on a group of 30 patients with non-insulin-dependent diabetes mellitus (NIDDM), who never received antidiabetic medication before, and on a group of 17 healthy adults. The patients were administered treatment with metformin, 1,000 mg/day. Plasmatic and urinary concentration of magnesium have been measured, copper and zinc along with the concentrations of glucose, HDL, LDL, cholesterol, tryglicerides, HbA1c, and total erythrocyte magnesium, in advance and after 3 months of treatment. Data showed significant differences in the NIDDM group vs the control group: for plasma magnesium-1.95 ± 0.19 vs 2.20 ± 0.18 mg/dl, p < 0.001; urine magnesium-237.28 ± 34.51 vs 126.25 ± 38.22 mg/24 h, p < 0.001; erythrocyte magnesium-5.09 ± 0.63 vs 6.38 ± 0.75 mg/dl, p < 0.001; plasma zinc-67.56 ± 6.21 vs 98.41 ± 20.47 μg/dl, p < 0.001; urine zinc-1,347.54 ± 158.24 vs 851.65 ± 209.75 μg/24 h, p < 0.001; plasma copper-111.91 ± 20.98 vs 96.33 ± 8.56 μg/dl, p < 0.001; and urine copper-51.70 ± 23.79 vs 36.00 ± 11.70 μg/24 h, p < 0.05. Treatment with metformin for 3 months modified significant erythrocyte magnesium-5.75 ± 0.61 vs 5.09 ± 0.63 mg/dl, p < 0.001 and urine magnesium-198.27 ± 27.07 vs 237.28 ± 34.51 mg/24 h, p < 0.001, whereas it did not modify significant the plasmatic and urinary concentration of the other cations. The erythrocyte magnesium concentration was inversely correlated with HbA1c (r = -0.438, p = 0.015). The plasma level of copper was positively correlated with HbA1c (r = 0.517, p < 0.003), tryglicerides (r = 0.534, p < 0.003), and cholesterol (r = 0.440, p < 0.05), and the plasma level of zinc was inversely correlated with glycemia (r = -0.399, p = 0.029). Our data show a significant action of metformin therapy, by increasing the total intraerythrocyte magnesium concentration and decreasing the urinary magnesium elimination, positively correlated with the decrease of glycemia and HbA1c in NIDDM patients.

Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial

BACKGROUND

Epidemiological data shows low dietary magnesium(Mg) may be related to incidence and progression of asthma.

OBJECTIVE

To determine if long term(6.5 month) treatment with oral Mg would improve asthma control and increase serum measures of Mg status in men and women with mild-to-moderate asthma.

SUBJECTS

55 males and females aged 21 to 55 years with mild to moderate asthma according to the 2002 National Heart, Lung, and Blood Institute(NHLBI) and Asthma Education and Prevention Program(NAEPP) guidelines and who used only beta-agonists or inhaled corticosteroids(ICS) as asthma medications were enrolled.

DESIGN

Subjects were randomly assigned to consume 340 mg(170 mg twice a day) of Mg or a placebo for 6.5 months.

MEASUREMENTS

Multiple measures of Mg status including serum, erythrocyte, urine, dietary, ionized and IV Mg were measured.

OBJECTIVE

markers of asthma control were: methacholine challenge test(MCCT) and pulmonary function test(PFT) results. Subjective validated questionnaires on asthma quality of life(AQLQ) and control(ACQ) were completed by participants. Markers of inflammation, including c-reactive protein(CRP) and exhaled nitric oxide(eNO) were determined.

RESULTS

The concentration of methacholine required to cause a 20% drop in forced expiratory volume in in minute(FEV(1)) increased significantly from baseline to month 6 within the Mg group. Peak expiratory flow rate(PEFR) showed a 5.8% predicted improvement over time(P = 0.03) in those consuming the Mg. There was significant improvement in AQLQ mean score units(P < 0.01) and in overall ACQ score only in the Mg group(P = 0.05) after 6.5 months of supplementation. Despite these improvements, there were no significant changes in any of the markers of Mg status.

CONCLUSION

Adults who received oral Mg supplements showed improvement in objective measures of bronchial reactivity to methacholine and PEFR and in subjective measures of asthma control and quality of life.

Multiple Measures of Magnesium Status Are Comparable in Mild Asthma and Control Subjects

Magnesium (Mg) may be a significant factor in asthma management. There is debate about how to best assess Mg status. We evaluated multiple indices of Mg status and lung function in 52 people with mild to moderate asthma and 47 controls. Mg measures included serum total, ionized and erythrocyte Mg, intravenous Mg load retention and dietary recall. Methacholine challenge and pulmonary function tests were used to assess diagnosis and severity of asthma. Mg status was similar in asthma and controls, and was not correlated to lung function. Total serum Mg closely reflected ionized Mg and offers a useful clinical diagnostic monitor.

Intravenous magnesium sulphate provides no additive benefit to standard management in acute asthma

BACKGROUND

Treatment of acute asthma is based on rapid reversal of bronchospasm and airway inflammation. Magnesium sulphate (MgSO(4)) is known to have a bronchodilator effect on smooth muscle but studies have shown conflicting results on its efficacy in acute asthma, although its use is recommended in national and international guidelines.

AIMS

To determine if intravenous MgSO(4), when used as an adjunct to standard therapy, improves the outcome in acute asthma.

METHODS

A double blind, randomised placebo controlled trial comparing 1.2g MgSO(4) with standard therapy in adult patients with acute asthma. Patients had a PEF <or=75% predicted and all were treated with oxygen, nebulised salbutamol and ipratropium, and IV hydrocortisone. They then received 1.2g IV MgSO(4) or placebo. Outcome measures were % predicted PEF at 60 min and hospital admission rates.

RESULTS

One hundred and twenty nine patients were studied. Placebo and active treatment groups were well matched at baseline. MgSO(4) had no benefit with regards hospital admission rates or % predicted PEF at 60 min (p=0.48) for the whole group, or for subgroups of life-threatening (p=0.85), severe (p=0.63) and moderate (p=0.67) acute asthma.

CONCLUSION

This study did not show additional benefit from 1.2g IV MgSO(4) when given as an adjunct to standard therapy for acute asthma.

Allogeneic activation is attenuated in a model of mouse lung perfused with magnesium-deficient blood

Hypomagnesemia, which is frequently observed in patients treated with calcineurin inhibitors to prevent rejection after allogeneic transplantation, has been associated with a faster rate of decline in allograft function. The effect of hypomagnesemia on lung allograft has not been reported yet. In our model of isolated mouse lung, we have evaluated the early effects of allogeneic lung perfusion with blood from magnesium (Mg)-deficient mice for 3 h on lung activation and remodelling, compared to isogeneic perfusion. Hypomagnesemia (0.21+/-0.07 mmol Mg(2+)/l) was observed in blood from Mg-deficient mice, but no inflammatory pattern. The mRNA level of the intercellular adhesion molecule (ICAM)-1, but neither of the vascular cell adhesion molecule (VCAM)-1, nor of the cytokines tumor necrosis factor (TNF)alpha and interleukin (IL)-2, was enhanced (p<0.05). Although caspase-3 mRNA was transiently enhanced, no apoptotic cells were evidenced in lung tissues even after 3 h. Using cDNA array, we found that the genes encoding RANKL, RANK, TNFR2, NFATX, IL-1R2, IL-6R gp130, SOCS3, PDGFRB, P63, CSF3R, CXCL1, CXCL5, CX3CL1, CSF1, which are involved in inflammation and apoptosis regulation, were markedly up-regulated in allogeneic conditions. Our results support a limited allogeneic activation and an early stage of the inflammatory process in lung, at the time of inflammatory cell recruitment without lung tissue remodelling, as a result of hypomagnesemia. These findings suggest that cyclosporine-related hypomagnesemia, observed in most of the transplanted patients, does not constitute an additional risk for lung allograft outcome.

Ionized magnesium levels and the ratio of ionized calcium to magnesium in asthma patients before and after treatment with magnesium

OBJECTIVE

Prior studies have been equivocal about the efficacy of magnesium therapy in acute asthma exacerbations. We hypothesize that pretreatment ionized magnesium (Mg(2+)) levels and/or the ratio of ionized calcium to ionized magnesium (Ca(2+)/Mg(2+)) may have been confounding variables in these previous studies. Here, we report on the incidence of abnormal divalent ion levels in our asthma population.

MATERIAL AND METHODS

The study was designed as a randomized, double-blind, placebo-controlled trial of intravenous magnesium. Inclusion criteria were: age >18 years, percentage predicted forced expiratory volume (FEV(1)) <75 % after an initial beta-agonist. African-American patients (AA) at an urban university hospital were randomized to 2 g IV Mg or placebo. Mg(2+) and Ca(2+)/Mg(2+) levels were measured pre- and post-infusion. Data were reported as means+/-SD. Student's t-test and Fisher's exact test were used where appropriate (alpha = 0.05, two tailed).

RESULTS

Fifty-five AA patients (mean age of 42.7 years+/-15.6 years, range 18-75 years) were studied. A significantly (p<0.05) lower level of Mg(2+) was found in asthma (AS) patients compared with that in the AA group, by 0.03 mmol/L (95 % CI, 0.007-0.053 mmol/L). The AS group had a mean increase in Ca(2+)/Mg(2+) ratios over the AA group, of 0.27 (95 % CI, 0.16-0.38); 100 % of patients with abnormal divalent ion levels were corrected with IV magnesium.

CONCLUSIONS

We identified a subgroup of asthmatic patients with significant abnormalities in their divalent ion concentrations, which was corrected with IV magnesium.

Magnesium deficiency in critical illness

Magnesium (Mg) deficiency commonly occurs in critical illness and correlates with a higher mortality and worse clinical outcome in the intensive care unit (ICU). Magnesium has been directly implicated in hypokalemia, hypocalcemia, tetany, and dysrhythmia. Moreover, Mg may play a role in acute coronary syndromes, acute cerebral ischemia, and asthma. Magnesium regulates hundreds of enzyme systems. By regulating enzymes controlling intracellular calcium, Mg affects smooth muscle vasoconstriction, important to the underlying pathophysiology of several critical illnesses. The principle causes of Mg deficiency are gastrointestinal and renal losses; however, the diagnosis is difficult to make because of the limitations of serum Mg levels, the most common assessment of Mg status. Magnesium tolerance testing and ionized Mg2+ are alternative laboratory assessments; however, each has its own difficulties in the ICU setting. The use of Mg therapy is supported by clinical trials in the treatment of symptomatic hypomagnesemia and preeclampsia and is recommended for torsade de pointes. Magnesium therapy is not supported in the treatment of acute myocardial infarction and is presently undergoing evaluation for the treatment of severe asthma exacerbation, for the prevention of post-coronary bypass grafting dysrhythmias, and as a neuroprotective agent in acute cerebral ischemia.