SARS-CoV-2: influence of phosphate and magnesium, moderated by vitamin D, on energy (ATP) metabolism and on severity of COVID-19.

The use of vitamin D to reduce the severity of COVID-19 complications is receiving considerable attention, backed by encouraging data. Its purported mode of action is as an immune modulator. Vitamin D, however, also affects the metabolism of phosphate and Mg, which may well play a critical role in SARS-CoV-2 pathogenesis. SARS-CoV-2 may induce a cytokine storm that drains ATP whose regeneration requires phosphate and Mg. These minerals, however, are often deficient in conditions that predispose people to severe COVID-19, including older age (especially males), diabetes, obesity, and usage of diuretics. Symptoms observed in severe COVID-19 also fit well with those seen in classical hypophosphatemia and hypomagnesemia, such as thrombocytopenia, coagulopathy, dysfunction of liver and kidneys, neurologic disturbances, immunodeficiency, failure of heart and lungs, delayed weaning from a respirator, cardiac arrhythmia, seizures, and, finally, multiorgan failure. Deficiencies of phosphate and Mg can be amplified by kidney problems commonly observed in patients with COVID-19 resulting in their wastage into urine. Available data show that phosphate and Mg are deficient in COVID-19, with phosphate showing a remarkable correlation with its severity. In one experiment, patients with COVID-19 were supplemented with a cocktail of vitamin D3, Mg, and vitamin B12, with very encouraging results. We, thus, argue that patients with COVID-19 should be monitored and treated for phosphate and Mg deficiencies, ideally already in the early phases of infection. Supplementation of phosphate and Mg combined with vitamin D could also be implemented as a preventative strategy in populations at risk.

Magnesium Status and Stress: The Vicious Circle Concept Revisited.

Magnesium deficiency and stress are both common conditions among the general population, which, over time, can increase the risk of health consequences. Numerous studies, both in pre-clinical and clinical settings, have investigated the interaction of magnesium with key mediators of the physiological stress response, and demonstrated that magnesium plays an inhibitory key role in the regulation and neurotransmission of the normal stress response. Furthermore, low magnesium status has been reported in several studies assessing nutritional aspects in subjects suffering from psychological stress or associated symptoms. This overlap in the results suggests that stress could increase magnesium loss, causing a deficiency; and in turn, magnesium deficiency could enhance the body's susceptibility to stress, resulting in a magnesium and stress vicious circle. This review revisits the magnesium and stress vicious circle concept, first introduced in the early 1990s, in light of recent available data.

[Hypomagnesemia in newborns with hypoxic ischemic encephalopathy and whole-body hypothermia]. / Hipomagnesemia en recién nacidos con encefalopatía hipóxico isquémica en hipotermia corporal total.

INTRODUCTION: In newborns with the diagnosis of hypoxic-ischemic encephalopathy (HIE) treated with hypother mia, metabolic alterations are observed, which are associated with neurological prognosis. Hypo magnesemia has been reported frequently in the literature in these patients, but it is not measured or corrected in all neonatal healthcare centers. OBJECTIVE: To evaluate the frequency of hypomag nesemia and hypocalcemia in newborns with HIE treated with whole-body hypothermia and to evaluate the response to the magnesium sulfate administration. PATIENTS AND METHOD: Prospective, observational and descriptive study in hospitalized newborns with the diagnosis of HIE and trea ted with whole-body hypothermia between the years 2016 and 2017. Serial blood measurement of magnesemia (Mg) and calcemia (Ca) was performed. When presenting an Mg level < 1.8 mg/dl, supplementation with magnesium sulfate was administered to maintain levels between 1.9 and 2.8 mg/dl. The frecuency of hypomagnesemia, hypocalcemia and clinical evolution was registered. A descriptive statistical analysis was performed, with central tendency measures. RESULTS: Sixteen ca ses were included, 13 of them presented hypomagnesemia (81.3%), with early-onset (6-36 hours of life), which was normalized with magnesium sulfate treatment, receiving a second dose 4 patients. Six of 16 patients presented hypocalcemia (37.5 %). CONCLUSIONS: Hypomagnesemia is frequent (80%), similar to that described in the literature, and should be controlled and corrected early, given its physiological role, in the same way that calcium is controlled.

Hipomagnesemia en recién nacidos con encefalopatía hipóxico isquémica en hipotermia corporal total / Hypomagnesemia in newborns with hypoxic ischemic encephalopathy and whole-body hypothermia

Resumen: Introducción: En recién nacidos (RN) con encefalopatía hipóxico isquémica (EHI) en hipotermia se describen alte raciones metabólicas que se asocian a pronóstico neurológico. La hipomagnesemia ha sido reportada en la literatura, pero no es medida ni corregida en todos los centros de atención neonatal. Objeti vo: Evaluar la frecuencia de hipomagnesemia e hipocalcemia en RN con EHI en tratamiento con hipotermia corporal total y evaluar la respuesta al aporte de sulfato de magnesio. Pacientes y Méto do: Estudio prospectivo, observational y descriptivo en RN con EHI sometidos a hipotermia corporal total, hospitalizados entre los años 2016-2017. Se realizó medición seriada en sangre de magnesemia (Mg) y calcemia (Ca). Con Mg menor o igual de 1,8 mg/dl se administró suplemento como sulfato de Mg para mantener niveles entre 1,9 y 2,8 mg/dl. Se describió la frecuencia de hipomagnesemia e hipocalcemia y su presentación en el tiempo. Se realizó registro prospectivo de evolución clínica. Se hizo un análisis estadístico descriptivo, con medidas de tendencia central. Resultados: Se incluyeron 16 pacientes. Presentaron hipomagnesemia 13/16 (81,3%), la que fue precoz (6-36 h de vida), nor malizándose con aporte de sulfato de magnesio, requiriendo 2a dosis 4 de ellos. Presentaron hipo- calcemia 6/16 (37,5%). Conclusiones: La hipomagnesemia es frecuente (80%), similar a lo descrito en la literatura. Dado su importancia fisiológica debe controlarse y corregirse, de igual manera que el calcio.

Abstract: Introduction: In newborns with the diagnosis of hypoxic-ischemic encephalopathy (HIE) treated with hypother mia, metabolic alterations are observed, which are associated with neurological prognosis. Hypo magnesemia has been reported frequently in the literature in these patients, but it is not measured or corrected in all neonatal healthcare centers. Objective: To evaluate the frequency of hypomag nesemia and hypocalcemia in newborns with HIE treated with whole-body hypothermia and to evaluate the response to the magnesium sulfate administration. Patients and Method: Prospective, observational and descriptive study in hospitalized newborns with the diagnosis of HIE and trea ted with whole-body hypothermia between the years 2016 and 2017. Serial blood measurement of magnesemia (Mg) and calcemia (Ca) was performed. When presenting an Mg level < 1.8 mg/dl, supplementation with magnesium sulfate was administered to maintain levels between 1.9 and 2.8 mg/dl. The frecuency of hypomagnesemia, hypocalcemia and clinical evolution was registered. A descriptive statistical analysis was performed, with central tendency measures. Results: Sixteen ca ses were included, 13 of them presented hypomagnesemia (81.3%), with early-onset (6-36 hours of life), which was normalized with magnesium sulfate treatment, receiving a second dose 4 patients. Six of 16 patients presented hypocalcemia (37.5 %). Conclusions: Hypomagnesemia is frequent (80%), similar to that described in the literature, and should be controlled and corrected early, given its physiological role, in the same way that calcium is controlled.

Effect of teduglutide on restoring oral autonomy for magnesium in two patients with short bowel.

It is not known whether Teduglutide can allow patients with Short bowel syndrome, previously dependent on continuous or periodic intravenous (IV) magnesium, to attain oral autonomy with or without supplementation. Here, we report on two patients previously dependent on continuous or intermittently administered IV magnesium to achieve autonomy from IV, one with and one without oral supplementation that was previously ineffective in both patients.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer.

BACKGROUND: Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review. OBJECTIVES: To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses. SEARCH METHODS: On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017. SELECTION CRITERIA: Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis. DATA COLLECTION AND ANALYSIS: Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. MAIN RESULTS: Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies. AUTHORS' CONCLUSIONS: The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Control of metabolic predisposition to cardiovascular complications of chronic kidney disease by effervescent calcium magnesium citrate: a feasibility study.

AIMS: Cardiovascular (CV) complications are common in chronic kidney disease (CKD). Numerous metabolic disturbances including hyperphosphatemia, high circulating calciprotein particles (CPP), hyperparathyroidism, metabolic acidosis, and magnesium deficiency are associated with, and likely pathogenic for CV complications in CKD. The goal of this feasibility study was to determine whether effervescent calcium magnesium citrate (EffCaMgCit) ameliorates the aforementioned pathogenic intermediates. METHODS: Nine patients with Stage 3 and nine patients with Stage 5D CKD underwent a randomized crossover study, where they took EffCaMgCit three times daily for 7 days in one phase, and a conventional phosphorus binder calcium acetate (CaAc) three times daily for 7 days in the other phase. Two-hour postprandial blood samples were obtained on the day before and on the 7th day of treatment. RESULTS: In Stage 5D CKD, EffCaMgCit significantly increased T50 (half time for conversion of primary to secondary CPP) from baseline by 63% (P = 0.013), coincident with statistically non-significant declines in serum phosphorus by 25% and in saturation of octacalcium phosphate by 35%; CaAc did not change T50. In Stage 3 CKD, neither EffCaMgCit nor CaAc altered T50. With EffCaMgCit, a significant increase in plasma citrate was accompanied by statistically non-significant increase in serum Mg and phosphate. CaAc was without effect in any of these parameters in Stage 3 CKD. In both Stages 3 and 5D, both drugs significantly reduced serum parathyroid hormone. Only EffCaMgCit significantly increased serum bicarbonate by 3 mM (P = 0.015) in Stage 5D. CONCLUSIONS: In Stage 5D, EffCaMgCit inhibited formation of CPP, suppressed PTH, and conferred magnesium and alkali loads. These effects were unique, since they were not observed with CaAc. In Stage 3 CKD, neither of the regimens have any effect. These metabolic changes suggest that EffCaMgCit might be useful in protecting against cardiovascular complications of CKD by ameliorating pathobiologic intermediates.

Hypomagnesemia and hypermagnesemia.

Introduction:Magnesium is an essential element which also has pleiotropic effects in humans. Recent studies have altered our interpretation of a disturbed magnesium balance both leading to hypomagnesemia and hypermagnesemia. Methods: a narrative review of their clinical relevance is presented. Results: Although magnesium balance is strictly controlled by the kidneys, hypomagnesemia is fairly common, especially in people with comorbid conditions. Increased renal magnesium wasting, often aggravated by drugs, is commonly found in conditions associated with unfavorable outcomes such as diabetes mellitus and sepsis. Depending on its severity hypomagnesemia may reveal itself by potentially hazardous neurological and cardiovascular symptoms. Intravenous magnesium is an evidence-based treatment of torsades de pointes and preeclampsia irrespective of the presence of preexisting hypomagnesemia. Magnesium deficiency and/or hypomagnesemia has been linked to cardiovascular disease, vascular calcification and endothelial function both in vitro and in vivo. (Severe) hypermagnesemia can be life-threatening but is almost exclusively observed in patients with substantially decreased kidney function associated with high magnesium intake through supplements or magnesium containing cathartics or antacids. Conclusion:It remains unclear whether mild hypermagnesemia confers survival benefit especially in subjects with decreased kidney function. The role of oral magnesium supplementation of chronic mild asymptomatic hypomagnesemia also merits further exploration through interventional studies in various study populations.

Dietary Magnesium Alleviates Experimental Murine Colitis Through Upregulation of the Transient Receptor Potential Melastatin 6 Channel.

Background: Magnesium (Mg) is essential for human health and is absorbed mainly in the intestine. In view of the likely occurrence of an Mg deficit in inflammatory bowel disease (IBD) and the documented role of Mg in modulating inflammation, the present study addresses whether Mg availability can affect the onset and progression of intestinal inflammation. Methods: To study the correlation between Mg status and disease activity, we measured magnesemia by atomic absorption spectroscopy in a cohort of IBD patients. The effects of dietary Mg modulation were assessed in a murine model of dextran sodium sulfate (DSS)-induced colitis by monitoring magnesemia, weight, fecal occult blood, diarrhea, colon length, and histology. Expression of the transient receptor potential melastatin (TRPM) 6 channel was assessed by real-time reverse transcription polymerase chain reaction and immunohistochemistry in murine colon tissues. The effect of Mg on epithelial barrier formation/repair was evaluated in human colon cell lines. Results: Inflammatory bowel disease patients presented with a substantial Mg deficit, and serum Mg levels were inversely correlated with disease activity. In mice, an Mg-deficient diet caused hypomagnesemia and aggravated DSS-induced colitis. Colitis severely compromised intestinal Mg2+ absorption due to mucosal damage and reduction in TRPM6 expression, but Mg supplementation resulted in better restoration of mucosal integrity and channel expression. Conclusions: Our results highlight the importance of evaluating and correcting magnesemia in IBD patients. The murine model suggests that Mg supplementation may represent a safe and cost-effective strategy to reduce inflammation and restore normal mucosal function.

Dietary Magnesium and Chronic Disease.

Although official magnesium (Mg) dietary reference intakes are open to question, a significant number of adults likely have intakes that are in the range of 50%-99% of the requirement. This moderate or marginal (subclinical) deficient Mg intake generally is asymptomatic. Animal studies, however, indicate that moderate or subclinical Mg deficiency primes phagocytic cells for the release of proinflammatory cytokines leading to chronic inflammatory and oxidative stress. Human studies have found that dietary Mg is inversely related to serum or plasma C-reactive protein (CRP). Individuals with apparently deficient Mg intakes have an increased likelihood of serum or plasma CRP ≥3.0 mg/L, considered an indicator of chronic inflammatory stress that increases the risk for chronic disease. In addition, elevated serum or plasma CRP in individuals with chronic disease is decreased by Mg supplementation, which suggests that Mg decreases the risk for chronic disease. The importance of dietary Mg intake on the risk for chronic disease through affecting inflammatory and oxidative stress is supported by numerous meta-analyses and systematic reviews that have found dietary Mg is inversely associated with chronic diseases such hypertension, ischemic heart disease, stroke, metabolic syndrome, diabetes, and colorectal cancer.

Magnesium and Blood Pressure: A Physiology-Based Approach.

Hypertension is an important public health challenge because of its high prevalence and strong association with cardiovascular disease and premature death. Hypertension is a major cause of CKD, is present in more than 80% of CKD patients, and contributes to CKD progression. Risk factors for hypertension include, but are not limited to, age, race, family history, obesity, physical inactivity, tobacco use, and inadequate intake of minerals such as calcium, potassium, and magnesium. Magnesium is the second most abundant intracellular cation in the human body and plays an important role in insulin and adenosine triphosphate metabolism. Low dietary magnesium intake has been associated with an increased risk of developing hypertension in prospective cohort studies. Moreover, clinical trials suggest that magnesium supplementation has blood pressure-lowering effects. In addition, emerging data reveal potential mechanisms by which magnesium may influence blood pressure. Here, we will review these mechanisms, using a physiology-based approach, focusing on the effects of magnesium on total peripheral resistance and cardiac output.

Efficacy and tolerability of magnesium plus protein for managing hypomagnesemia in pediatric kidney transplant patients.

We sought to investigate whether magnesium oxide bound to soy protein (MGP) increases serum magnesium concentrations with less diarrhea compared to commonly prescribed magnesium salts. Subjects were switched to MGP at a near-equivalent daily elemental magnesium dose. Mean serum magnesium levels were compared. If magnesium levels remained <1.7 mg/dL after switching to MGP, subjects were enrolled into Part 2 and received a one-time MGP dose adjustment. The MGP daily dose was increased by 266 mg. For both parts 1 and 2, subjects recorded the number and quality of their stools to assess gastrointestinal (GI) tolerability of MGP. Twelve pediatric kidney transplant recipients completed Part 1. Mean serum magnesium levels increased from 1.61 (SD 0.1) on standard MG to 1.69 (SD 0.1); t(11) = 2.6, P = .02 on MGP. Five subjects completed Part 2, and all achieved serum magnesium ≥1.7 mg/dL (mean 1.75 mg/dL, SD 0.06; t(4) = 2.7, P = .06). Subjects reported the same number of, but looser bowel movements with MGP; however, individuals did not perceive intolerable GI symptoms with MGP therapy and all chose to remain on MGP at the end of the study. At an equivalent mg/kg/d dose of elemental magnesium, serum magnesium levels on MGP were significantly higher.

The refeeding syndrome. Importance of phosphorus. / El síndrome de realimentación. Importancia del fósforo.

Refeeding syndrome (RS) is a complex disease that occurs when nutritional support is initiated after a period of starvation. The hallmark feature is the hypophosphataemia, however other biochemical abnormalities like hypokalaemia, hypomagnesaemia, thiamine deficiency and disorder of sodium and fluid balance are common. The incidence of RS is unknown as no universally accepted definition exists, but it is frequently underdiagnosed. RS is a potentially fatal, but preventable, disorder. The identification of patients at risk is crucial to improve their management. If RS is diagnosed, there is one guideline (NICE 2006) in place to help its treatment (but it is based on low quality of evidence). The aims of this review are: highlight the importance of this problem in malnourished patients, discuss the pathophysiology and clinical characteristics, with a final series of recommendations to reduce the risk of the syndrome and facilitate the treatment.

Magnesium to counteract elastin degradation and vascular calcification in chronic obstructive pulmonary disease.

Accelerated elastin degradation is an important pathogenic mechanism in chronic obstructive pulmonary disease (COPD) leading to irreversible lung function loss and cardiovascular comorbidities. The rate of elastin breakdown is a predictor of mortality in patients with COPD. Decelerating elastinolysis might be an attractive therapeutic target in this debilitating condition. Vascular calcification starts in the elastin network of the arterial wall and is enhanced in patients with COPD. Elastin calcification is accompanied by an upregulation of matrix metalloproteinase gene expression and consequently a shift in the elastase/anti-elastase balance towards degradation. Magnesium can be regarded as a natural calcium antagonist and has the proven ability to ameliorate vascular calcification. Furthermore, an animal study has suggested that magnesium deficiency promotes elastin degradation. I hypothesize that inhibiting elastin calcification by means of magnesium supplementation might counteract both vascular calcification and elastin degradation in COPD. This could potentially have a favorable impact on cardiovascular and respiratory related morbidity/mortality in patients with COPD.

Inhibition of TRPM7 suppresses cell proliferation of colon adenocarcinoma in vitro and induces hypomagnesemia in vivo without affecting azoxymethane-induced early colon cancer in mice.

BACKGROUND: Magnesium (Mg2+) is an essential cation implicated in carcinogenesis, solid tumor progression and metastatic potential. The Transient Receptor Potential Melastatin Member 7 (TRPM7) is a divalent ion channel involved in cellular and systemic Mg2+ homeostasis. Abnormal expression of TRPM7 is found in numerous cancers, including colon, implicating TRPM7 in this process. METHODS: To establish a possible link between systemic magnesium (Mg2+) status, the Mg2+ conducting channel TRPM7 in colon epithelial cells, and colon carcinogenesis, in vitro whole-cell patch clamp electrophysiology, qPCR, and pharmacological tools were used probing human colorectal adenocarcinoma HT-29 as well as normal primary mouse colon epithelial cells. This was extended to and combined with aberrant crypt foci development in an azoxymethane-induced colorectal cancer mouse model under hypomagnesemia induced by diet or pharmacologic intervention. RESULTS: We find that TRPM7 drives colon cancer cell proliferation in human HT-29 and expresses in normal primary mouse colon epithelia. This is linked to TRPM7's dominant role as Mg2+ transporter, since high extracellular Mg2+ supplementation cannot rescue inhibition of cell proliferation caused by suppressing TRPM7 either genetically or pharmacologically. In vivo experiments in mice provide evidence that the specific TRPM7 inhibitor waixenicin A, given as a single bolus injection, induces transient hypomagnesemia and increases intestinal absorption of calcium. Repeated injections of waixenicin A over 3 weeks cause hypomagnesemia via insufficient Mg2+ absorption by the colon. However, neither waixenicin A, nor a diet low in Mg2+, affect aberrant crypt foci development in an azoxymethane-induced colorectal cancer mouse model. CONCLUSION: Early stage colon cancer proceeds independent of systemic Mg2+ status and TRPM7, and waixenicin A is a useful pharmacological tool to study of TRPM7 in vitro and in vivo.

Attenuating trabecular morphology associated with low magnesium diet evaluated using micro computed tomography.

OBJECTIVE: The literature shows that bone mineral density (BMD) and the geometric architecture of trabecular bone in the femur may be affected by inadequate dietary intake of Mg. In this study, we used microcomputed tomography (micro-CT) to characterize and quantify the impact of a low-Mg diet on femoral trabecular bones in mice. MATERIALS AND METHODS: Four-week-old C57BL/6J male mice were randomly assigned to 2 groups and supplied either a normal or low-Mg diet for 8weeks. Samples of plasma and urine were collected for biochemical analysis, and femur tissues were removed for micro-CT imaging. In addition to considering standard parameters, we regarded trabecular bone as a cylindrical rod and used computational algorithms for a technical assessment of the morphological characteristics of the bones. BMD (mg-HA/cm3) was obtained using a standard phantom. RESULTS: We observed a decline in the total tissue volume, bone volume, percent bone volume, fractal dimension, number of trabecular segments, number of connecting nodes, bone mineral content (mg-HA), and BMD, as well as an increase in the structural model index and surface-area-to-volume ratio in low-Mg mice. Subsequently, we examined the distributions of the trabecular segment length and radius, and a series of specific local maximums were identified. The biochemical analysis revealed a 43% (96%) decrease in Mg and a 40% (71%) decrease in Ca in plasma (urine excretion). CONCLUSIONS: This technical assessment performed using micro-CT revealed a lower population of femoral trabecular bones and a decrease in BMD at the distal metaphysis in the low-Mg mice. Examining the distributions of the length and radius of trabecular segments showed that the average length and radius of the trabecular segments in low-Mg mice are similar to those in normal mice.

Oral magnesium supplementation improves glycemic control and lipid profile in children with type 1 diabetes and hypomagnesaemia.

Dietary supplementation with magnesium (Mg) in addition to classical therapies for diabetes may help in prevention or delaying of diabetic complications.We aimed to evaluate the status of serum Mg in children with type 1 diabetes and assessing its relationship to glycemic control and lipid profile. Then evaluating the effect of oral Mg supplementation on glycemic control and lipid parameters.We included 71 children at Pediatric Endocrinology Outpatient Clinic, Zagazig University, Egypt with type 1 diabetes and assessed HBA1c, lipid profile, and serum Mg at the start of study. Patients with serum Mg level < 1.7 mg/dL were given 300 mg Mg oxide for 3 months. After that we reevaluated HBA1c, lipid profile, and serum Mg in all patients.The study included 71 patients with type 1 diabetes (32 males and 39 females); their mean age was 9.68 ±â€Š3.99 years. The mean serum Mg level was 1.83 ±â€Š.27 mg/dL. Hypomagnesemia was detected in 28.2% study patients. Serum Mg was found to be positively correlated with high density lipoprotein, mean corpuscular volume and platelet count (P < 0.001), and negatively correlated with age, HbA1c, triglycerides, total cholesterol, low density lipoprotein, and duration of diabetes (P < 0.001). There was significant reduction in HBA1c in group given Mg supplementation. HBA1c was initially 10.11% ±â€Š0.87%. After 3 months of oral Mg supplementation it is reduced to 7.88% ±â€Š0.42% (P < 0.001). There was statistically significant difference in lipid parameters in hypomagnesemic diabetic patients before and after Mg supplementation with significant reduction in serum triglycerides, LDL, and total cholesterol following Mg supplementation with P < 0.001. Although HDL shows a significant increase after Mg supplementation in hypomagnesemic diabetic children with P < 0.001.Correction of hypomagnesemia in type 1 diabetic children with oral Mg supplements is associated with optimization of glycemic control and reduction of atherogenic lipid fraction as well as increase in protective lipid fraction.

Management of a severe case of Gitelman syndrome with poor response to standard treatment.

Gitelman syndrome is an autosomal recessive distal renal tubular disorder caused by defective sodium chloride transporters. Biochemically, it presents with hypokalaemic metabolic alkalosis, hypomagnesaemia and hypocalciuria. It is usually managed with oral potassium supplements and potassium-sparing diuretics. We report a case of a 28-year-old woman whose condition worsened during pregnancy; she became resistant to standard management after delivery of her second child. She was managed in a specialist metabolic clinic through a comprehensive approach including perseverance with oral potassium supplement, weekly intravenous potassium and magnesium infusion, correction of vitamin D level and the offering of appropriate dietary advice; this controlled the patient's symptoms and prevented repeated hospital admissions. In this case report, we illustrate a patient's presentation and diagnosis with Gitelman syndrome, discuss triggers of exacerbation, review the relevant literature in terms of differential diagnoses and provide practical advice on the management of difficult cases in a specialist clinic.

PARK7/DJ-1 dysregulation by oxidative stress leads to magnesium deficiency: implications in degenerative and chronic diseases.

Disturbed magnesium (Mg(2+)) homoeostasis and increased levels of OS (oxidative stress) are associated with poor clinical outcomes in patients suffering from neurodegenerative, cardiovascular and metabolic diseases. Data from clinical and animal studies suggest that MD (Mg(2+) deficiency) is correlated with increased production of ROS (reactive oxygen species) in cells, but a straightforward causal relationship (including molecular mechanisms) between the two conditions is lacking. The multifactorial protein PARK7/DJ-1 is a major antioxidant protein, playing a key role in cellular redox homoeostasis, and is a positive regulator of AR (androgen receptor)-dependent transcription. SLC41A1 (solute carrier family 41 member 1), the gene encoding a ubiquitous cellular Mg(2+)E (Mg(2+)efflux) system, has been shown to be regulated by activated AR. We hypothesize that overexpression/up-regulation of PARK7/DJ-1, attributable to OS and related activation of AR, is an important event regulating the expression of SLC41A1 and consequently, modulating the Mg(2+)E capacity. This would involve changes in the transcriptional activity of PARK7/DJ-1, AR and SLC41A1, which may serve as biomarkers of intracellular MD and may have clinical relevance. Imipramine, in use as an antidepressant, has been shown to reduce the Mg(2+)E activity of SLC41A1 and OS. We therefore hypothesize further that administration of imipramine or related drugs will be beneficial in MD- and OS-associated diseases, especially when combined with Mg(2+) supplementation. If proved true, the OS-responsive functional axis, PARK7/DJ-1-AR-SLC41A1, may be a putative mechanism underlying intracellular MD secondary to OS caused by pro-oxidative stimuli, including extracellular MD. Furthermore, it will advance our understanding of the link between OS and MD.