Intracellular magnesium of mononuclear cells from venous blood of clinically healthy subjects

The Association Between Serum Magnesium Level and Microalbuminuria in Type 2 Diabetes Mellitus Patients

Background: Diabetic nephropathy occurs in 20 - 30% of diabetic cases globally, and microalbuminuria (MA) is the first symptom of this disorder. Some studies have suggested that there is an association between the serum magnesium (Mg) level and MA. Objectives: Therefore, we investigated the association between the serum Mg level and MA in type 2 diabetes mellitus (T2DM) patients. Methods: We conducted a cross-sectional study on 122 subjects with T2DM. We categorized them into two groups of microalbuminuria (MA) and non-microalbuminuria (NMA) according to their urine albumin-creatinine ratio (UACR). MA was considered as a UACR of 30 to 300 mg/g. Participants were excluded if they had the following conditions: The age of under 16 years, cardiac, renal, or hepatic disorders, using corticosteroids, diuretics, Mg /calcium (Ca) supplements, and antiepileptic drugs, heavy physical activity within 24 hours before the test, pregnant and breastfeeding women, febrile patients, and patients who were unwilling to participate in the study. The analysis was performed using SPSS version 15. A P-value < 0.05 was considered significant. Results: Among the patients, 50.81% were male. Also, the mean body mass index (BMI) of the NMA group was greater than the MA group (29.84 ± 5.64 vs. 27.31 ± 3.14, P-value = 0.003). Mg levels of the MA and NMA groups showed no significant differences (2.13 ± 0.42 and 2.10 ± 0.43, respectively; P-value = 0.67). Overall, data analysis provided no significant difference between Mg level and the urine albumin concentration between the MA and NMA groups (P-value = 0.21 and 0.81, respectively.). Conclusions: Serum Mg level and MA have no significant relationship. Further prospective studies are needed to assay this issue.

Status of serum magnesium in Egyptian children with type 1 diabetes and its correlation to glycemic control and lipid profile

Diabetes mellitus has been suggested to be the most common metabolic disorder associated with magnesium deficiency, having 25% to 39% prevalence. This deficit could be associated with the development of late diabetic complications, especially macroangiopathy.We aimed to evaluate the status of serum Mg in children with type 1 diabetes and assess its relation to glycemic control and lipid profile.We included 71 Egyptian children with type 1diabetes having their follow-up at Pediatric Endocrinology outpatient clinic, Zagazig University Hospital and 71 age- and sex-matched control. We measured Serum magnesium, HbA1c, and lipid profile in all study subjects.Diabetic children had significantly lower serum magnesium level compared to control children (1.83 ± .27 mg/dL in diabetic children versus 2.00 ± .16 mg/dL in control children). Taking cut-off level of serum magnesium <1.7 mg/dL for definition of hypomagnesemia, hypomagnesemia was detected in 28.2% of diabetic children compared to 9.9% of control children. In diabetic patients, there was statistically significant difference in HbA1c between hypomagnesemic and normomagnesemic group being higher in the low magnesium group, as it is mean ± SD was 11.93 ± 3.17 mg/dL in group I versus 8.92 ± 0.93 mg/dL in the normomagnesemic group. Serum magnesium was found to be positively correlated with HDL (P < 0.001), and negatively correlated with age, HbA1c, triglycerides, total cholesterol, LDL, and duration of diabetes (P < 0.001).We concluded that total serum magnesium was frequently low in Egyptian children with type 1 diabetes and it is correlated with HbA1c and with lipid profile. Hypomagnesemia was more evident in patients with poor diabetic control and those with higher atherogenic lipid parameters. We suggest that low serum magnesium may be included in pathogenesis of poor glycemic control and abnormal lipid profile in children with type 1 diabetes. We need to perform further studies on giving magnesium supplements in diabetic children with hypomagnesemia to observe the effect of correction of serum magnesium on glycemic control, lipid profile, and the risk of diabetic complications.

Association of Serum Magnesium Level with Odds of Prediabetes and Diabetes in a Southern Chinese Population: a Prospective Nested Case-Control Study

Although emerging clinical evidence supports that magnesium deficiency is a risk factor for the development of type 2 diabetes, there are sparse studies concerning the dynamic change of serum magnesium with the risk of diabetes and its early stages. In this nested case-control study, we performed a 75-g oral glucose tolerance test or a standardized steamed bread meal test in 178 subjects with incident glucose metabolism impairment (33 with type 2 diabetes and 145 with prediabetes) and 178 matched controls at baseline and at 3-year follow-up and determined the associations between baseline serum magnesium levels as well as changes in serum magnesium levels at follow-up and odds of prediabetes and diabetes. After adjusting for potential confounders, the odds ratios of risk for prediabetes and type 2 diabetes in the highest quartile of serum magnesium levels were 0.22 (95 % confidence intervals [CI] 0.10-0.49; p for trend <0.001) and 0.02 (95 % CI 0.00-0.29; p for trend = 0.009), respectively, as compared with the lowest quartile. In addition, a significant decline in the serum magnesium level was detected in type 2 diabetes cases (p = 0.015) at 3 years as compared with at baseline. These results suggest that a low magnesium level is an independent risk factor for prediabetes and type 2 diabetes, and that the reduction of serum magnesium is associated with type 2 diabetes in a southern Chinese population.

Oral magnesium supplementation improves glycaemic status in subjects with prediabetes and hypomagnesaemia: A double-blind placebo-controlled randomized trial

AIM

This study evaluated the efficacy of oral magnesium supplementation in the reduction of plasma glucose levels in adults with prediabetes and hypomagnesaemia.

METHODS

A total of 116 men and non-pregnant women, aged 30 to 65 years with hypomagnesaemia and newly diagnosed with prediabetes, were enrolled into a randomized double-blind placebo-controlled trial to receive either 30 mL of MgCl2 5% solution (equivalent to 382 mg of magnesium) or an inert placebo solution once daily for four months. The primary trial endpoint was the efficacy of magnesium supplementation in reducing plasma glucose levels.

RESULTS

At baseline, there were no significant statistical differences in terms of anthropometric and biochemical variables between individuals in the supplement and placebo groups. At the end of follow-up, fasting (86.9 ± 7.9 and 98.3 ± 4.6 mg/dL, respectively; P = 0.004) and post-load glucose (124.7 ± 33.4 and 136.7 ± 23.9 mg/dL, respectively; P = 0.03) levels, HOMA-IR indices (2.85 ± 1.0 and 4.1 ± 2.7, respectively; P = 0.04) and triglycerides (166.4 ± 90.6 and 227.0 ± 89.7, respectively; P = 0.009) were significantly decreased, whereas HDL cholesterol (45.6 ± 10.9 and 46.8 ± 9.2 mg/dL, respectively; P = 0.04) and serum magnesium (1.96 ± 0.27 and 1.60 ± 0.26 mg/dL, respectively; P = 0.005) levels were significantly increased in those taking MgCl2 compared with the controls. A total of 34 (29.4%) people improved their glucose status (50.8% and 7.0% in the magnesium and placebo groups, respectively; P < 0.0005).

CONCLUSION

Our results show that magnesium supplementation reduces plasma glucose levels, and improves the glycaemic status of adults with prediabetes and hypomagnesaemia.

Effect of various clinical variables on total intracellular magnesium in hospitalized normomagnesemic diabetic patients before discharge

Deficiency of intracellular magnesium (icMg) may coexist with normal serum Mg levels. Little is known about clinical and pharmacological factors affecting icMg in normomagnesemic patients with diabetes mellitus (DM). Moreover, no information exists regarding the icMg state in diabetic patients after acute illness and before hospital discharge. We have evaluated the effect of antihyperglycemic medications and other relevant clinical variables on icMg in 119 such patients. Total icMg was measured in peripheral blood mononuclear cells. Twenty healthy volunteers served as controls. IcMg content (microg/mg cell protein) was lower in DM compared to controls (1.74 +/- 0.44 vs 2.4 +/- 0.39, p < 0.001). It was also significantly lower in patients treated with insulin (1.57 +/- 0.31 vs 1.8 +/- 0.46, p = 0.01), while metformin treatment was associated with higher icMg (1.86 +/- 0.49 vs 1.63 +/- 0.35, p = 0.003). After adjustment for age, gender, and concomitant use of other hypoglycemic drugs, only treatment with metformin was independently associated with increased icMg (p = 0.03). No statistically significant association or correlation was found between icMg content and age, causes of hospitalization, comorbid conditions, treatment with other drugs, concentrations of HbA1c, serum glucose, Mg, or creatinine. In conclusion, icMg is depleted in normomagnesemic DM patients. Insulin treatment is associated with worsening of icMg status, while metformin treatment may confer protective effect.

Deficiência de magnésio e resistência à insulina em pacientes com diabetes mellitus tipo 2

O magnésio é um íon predominantemente intra-celular, que participa como co-fator de mais de 300 reações enzimáticas, dentre elas na atividade da tirosino-cinase. Sua deficiência pode aumentar a resistência periférica à insulina, especialmente em pacientes com síndrome metabólica e diabetes mellitus tipo 2 (DM2). Este trabalho avaliou, em 27 pacientes com DM2 descompensado, o conteúdo intra-celular de magnésio, correlacionando-o com índices laboratoriais de resistência insulínica e controle glicêmico. Hipomagnesemia foi encontrada em 75% dos pacientes e déficit intra-celular em 30,8%. Houve correlação negativa do Mg intra-celular (Mg IC) com HbA1 e com IMC. 59,2% dos pacientes apresentaram HOMA IR > 3,5, e tendência para correlação negativa com o Mg IC, porém sem significância estatística. Apesar do número pequeno de pacientes, ressalta-se que uma vez que deficiência de magnésio é comum em pacientes com diabetes, sua relação com resistência insulínica deve ser mais estudada.

The role of magnesium in the pathogenesis of bone disease in childhood cholestatic liver disease: a preliminary report

BACKGROUND

Magnesium deficiency may contribute to the metabolic bone disease that complicates chronic cholestatic liver disease. We hypothesized that magnesium deficiency alters vitamin D metabolism by decreasing parathyroid hormone (PTH) response, resulting in decreased serum osteocalcin and decreased bone accretion.

METHODS

Nine subjects, age 3-22 years, with cholestatic liver disease were evaluated with the magnesium retention test. The response of PTH, 1,25(OH)2 vitamin D, and osteocalcin to provocative stimuli and dual x-ray absorptiometry measurement of bone mineral density (BMD) of the lumbar spine were assessed. Thereafter, subjects were treated with oral magnesium supplements.

RESULTS

All nine subjects were magnesium depleted. Repletion with magnesium was successful in seven subjects, and required 4 to 31 (median 14) months with doses of 6 to 34 (median 11) mg/kg/day. Baseline serum PTH was significantly reduced in the cholestatic subjects compared to 15 age-matched controls. Comparison of baseline to repleted provocative testing was performed in six Mg-repleted subjects. Osteocalcin response increased significantly (p = 0.048) with repletion, while PTH response increased (p = 0.061). Lumbar spine BMD increased modestly with repletion (p = 0.093).

CONCLUSIONS

This preliminary report suggests that magnesium depletion is extremely common in children with chronic cholestasis. We speculate that magnesium supplementation may be warranted to forestall the progression of metabolic bone disease in chronic cholestasis.

Magnesium deficiency and cardiogenic shock after cardiopulmonary bypass

Magnesium is an important cation that has a key role in cellular processes of energy transfer and utilization involving adenosine triphosphate, and influences cell membrane functions. Its antiarrhythmic properties are well-known and it is widely recognized as an adjunct for the treatment of arrhythmias after myocardial infarction and cardiopulmonary bypass. Magnesium may influence hemodynamic performance through its effects on vascular tone, modulation of intracellular calcium, regulation of catecholamine activity, and its essential role in adenosine triphosphate metabolism. The potential for magnesium deficiency to affect cardiovascular performance may be especially relevant in ischemic states. We report a case of cardiogenic shock developing after cardiopulmonary bypass that was initially unresponsive to therapeutic intervention, but that resolved promptly after magnesium administration. The potential role of magnesium in enhancing hemodynamic performance is discussed, with a review of its cellular metabolic properties and activities.

Precision of the magnesium determination in mononuclear blood cells and erythrocytes

OBJECTIVE

Establishing the analytical variation and reproducibility of the intracellular magnesium (Mg) assay in mononuclear blood cells (MBC) and erythrocytes (RBC).

DESIGN AND METHODS

We assessed the analytical variation of the several determination steps, and the reproducibility for the complete intracellular Mg-assay (combination of preanalytical, analytical, and biological variation). The influence of platelets was determined by comparing Mg concentrations obtained from heparinized blood and defibrinated blood.

RESULTS

Coefficients of variation of the several determination steps used in the MBC- and RBC-assay were < or = 5.4%. The overall analytical variation was 5.0-6.8%, and reproducibility of the complete Mg-assay 11.6-14.0%. Mg measurements in MBC (expressed as fmol/cell) obtained from heparinized blood showed significantly higher values than those obtained from defibrinated blood.

CONCLUSION

This is the first study to describe in detail reproducibility data for the individual steps in the overall procedure to measure intracellular magnesium. It is shown that results obtained in daily practice should be interpreted with care. Moreover, the removal of platelets is essential in the determination of Mg in MBC.

Mononuclear blood cell magnesium in older subjects: evaluation of its use in clinical practice

Serum and mononuclear blood cell (MBC) magnesium were measured in 24 healthy community subjects, average age 76 years (67-93), and in 21 ill hospitalized subjects, average age 79 years (65-90). MBC magnesium, expressed as mumol/mg protein, was significantly lower in the in-patient group (P < 0.001), but tended to be higher in the same group when expressed as fmol/cell (not significant). Further samples from community subjects on the same day, and again at 7 days, revealed coefficients of variation for intrasubject analysis of 12% and 22%, respectively (fmol/cell). The equivalent intrasubject values for serum were 2.8% on the same day and 4% at 1 week. MBC magnesium values for inpatients were probably distorted by changes in cell size and cell protein content caused by illness. Biological variability and the effects of illness on the composition and size of cells seem to limit the usefulness of MBC magnesium measurement as a clinical tool for assessment of body magnesium status.

Can the magnesium content of mononuclear blood cells be altered by oral magnesium supplementation?

A randomized, double-blind, placebo-controlled trial was performed on a rigorously defined group of normal subjects to see if magnesium (Mg) supplementation could affect serum Mg levels or Mg content of mononuclear blood cells. Forty-nine subjects were randomized to either placebo, tablets containing 90% United States recommended daily allowance (USRDA) of Mg, or tablets containing 180% USRDA of Mg. We were unable to demonstrate a statistically significant increase in Mg content of mononuclear blood cells.

Magnesium deficiency: recognition and treatment in the emergency medicine setting

Magnesium deficiency and its clinical manifestations are common in patients presenting to the emergency department. Assessment of the total body magnesium status of a patient is problematic since the serum magnesium concentration, the only readily available clinical test for this condition, may not be accurate in predicting the intracellular magnesium concentration. Therefore, empiric magnesium therapy should be considered in high-risk patients. Since magnesium participates in numerous metabolic processes in the body, a deficiency can affect multiple organ systems and present clinically in a variety of ways. Magnesium deficiency is reviewed in this paper with regard to therapeutic implications; specific treatment guidelines are given including dose, infusion rate, and magnesium preparation. Magnesium is also reviewed with regard to its homeostasis and metabolic role in the body. Special mention is made regarding precautions for use of magnesium in the setting of renal insufficiency.

Clinical correlates of the molecular and cellular actions of magnesium on the cardiovascular system

Magnesium is a ubiquitous element that participates in metabolic processes essential for life. Magnesium acts as a metallic cofactor in more than 300 enzymatic reactions; notably it is essential for all reactions requiring ATP. Magnesium also functions as a transmembrane and intracellular modulator of other ions. Altered magnesium homeostasis, particularly a deficiency, can cause alterations in metabolic functions that result in clinically recognizable events. Recognition of magnesium deficiency is problematic, since there is no test that will reliably and consistently detect this condition. A high index of suspicion for magnesium deficiency is necessary and treatment should be given when indicated. This article reviews the molecular and cellular actions of magnesium and correlates these basic scientific findings with clinically recognized cardiovascular events in humans. In addition, management guidelines are delineated.

Myocardial magnesium: relation to laboratory and clinical variables in patients undergoing cardiac surgery

Magnesium concentration was measured in the right atrial appendage of 100 patients undergoing cardiac surgery and associations with serum and mononuclear blood cell magnesium, other laboratory values and patient clinical variables were studied. In addition, magnesium was measured in the right atrial appendage and left ventricular free wall in 23 autopsy subjects to determine whether there was a proportional relation between right atrial appendage and left ventricular free wall magnesium. The mean left ventricular free wall/right atrial appendage magnesium ratio was 2.13 +/- 0.39 (r = 0.67, p = 0.0009). In the group with cardiac surgery, the right atrial appendage magnesium concentration correlated inversely with age (r = -0.54, p = 0.001). The mean right atrial appendage magnesium concentration (micrograms/g wet weight tissue) was lower in patients with postoperative cardiac arrhythmia than in those without arrhythmia (103 +/- 13 versus 111 +/- 10, p = 0.009) and in diabetic than in nondiabetic patients (103 +/- 13 versus 109 +/- 12, p = 0.02). The right atrial appendage magnesium concentration also tended to be lower in patients receiving potassium/magnesium-losing diuretics, although this difference did not achieve statistical significance (105 +/- 14 versus 109 +/- 11, p = 0.16). Right atrial appendage magnesium concentration correlated positively with serum creatinine concentration (r = 0.31, p = 0.002) and negatively with serum calcium concentration (r = -0.29, p = 0.013). Serum magnesium did not correlate with right atrial appendage or mononuclear blood cell magnesium concentration or clinical variables. There was a statistically significant correlation between mononuclear blood cell and right atrial appendage magnesium concentrations in some subgroups of patients.

Blood magnesium parameters do not differ with age

The relationship between age and blood magnesium (Mg) parameters has not been defined. Mg measurements in plasma, red blood cells (RBCs), and mononuclear blood cells (MBCs) were made in 104 normal volunteers (43 males and 61 females, ages 11-75 years). MBCs were separated from blood using a discontinuous Ficoll-Hypaque gradient. The mean values (+/- SEM) were as follows: plasma Mg 1.63 +/- 0.01 mEq/L, RBC Mg 4.55 +/- 0.06 mEq/L, MBC Mg content 72.8 +/- 1.0 fg/cell, and MBC Mg concentration 19.6 +/- 0.3 mEq/L. We compared these parameters with age (intervals of 10 years) using analysis of variance (ANOVA) and found no significant differences (p greater than 0.05). Thus, plasma, RBC, and MBC Mg parameters do not vary significantly between the ages of 11 and 75 years.