Evaluating the effect of magnesium supplementation and cardiac arrhythmias after acute coronary syndrome: a systematic review and meta-analysis.

BACKGROUND: Atrial and ventricular cardiac arrhythmias are one of the most common early complications after cardiac surgery and these serve as a major cause of mortality and morbidity after cardiac revascularization. We want to evaluate the effect of magnesium sulfate administration on the incidence of cardiac arrhythmias after cardiac revascularization by doing this systematic review and meta-analysis. METHODS: The search performed in several databases (SID, Magiran, IranDoc, IranMedex, MedLib, PubMed, EmBase, Web of Science, Scopus, the Cochrane Library and Google Scholar) for published Randomized controlled trials before December 2017 that have reported the association between Magnesium consumption and the incidence of cardiac arrhythmias. This relationship measured using odds ratios (ORs) with a confidence interval of 95% (CIs). Funnel plots and Egger test used to examine publication bias. STATA (version 11.1) used for all analyses. RESULTS: Twenty-two studies selected as eligible for this research and included in the final analysis. The total rate of ventricular arrhythmia was lower in the group receiving magnesium sulfate than placebo (11.88% versus 24.24%). The same trend obtained for the total incidence of supraventricular arrhythmia (10.36% in the magnesium versus 23.91% in the placebo group). In general the present meta-analysis showed that magnesium could decrease ventricular and supraventricular arrhythmias compared with placebo (OR = 0.32, 95% CI 0.16-0.49; p < 0.001 and OR = 0.42, 95% CI 0.22-0.65; p < 0.001, respectively). Subgroup analysis showed that the effect of magnesium on the incidence of cardiac arrhythmias was not affected by clinical settings and dosage of magnesium. Meta-regression analysis also showed that there was no significant association between the reduction of ventricular arrhythmias and sample size. CONCLUSION: The results of this meta-analysis study suggest that magnesium sulfate can be used safely and effectively and is a cost-effective way in the prevention of many of ventricular and supraventricular arrhythmias.

Serum levels of magnesium and their relationship with CRP in patients with OSA.

BACKGROUND: Low levels of magnesium (Mg) are associated with chronic inflammatory stress. Some animal studies have reported that a moderate deficiency of Mg, similar to that which occurs in humans, may increase inflammatory or oxidative stress stimulated by other factors, such as disrupted sleep or sleep deficiency. PURPOSE: This cross-sectional study evaluated the relationship between serum levels of Mg and the inflammatory response in patients with a new diagnosis of obstructive sleep apnea (OSA). METHODS: This clinical, retrospective study registered 68 patients with newly diagnosed mild to severe OSA and 30 without OSA. The Apnea-Hypopnea Index (AHI), oxygen desaturation index (ODI), time until blood hemoglobin oxygen saturation <90 % (SpO2 <90 %), and mean blood hemoglobin SpO2 were measured. Serum levels of Mg, plasma C-reactive protein (CRP), and total sleep time (TST) by polysomnography were also measured. RESULTS: Mg levels were lower in patients with OSA than those in controls matched for age, sex, and body mass index (BMI). Patients with OSA had substantially higher plasma CRP concentrations than controls. A negative correlation was observed between the AHI and ODI and Mg levels. Significant differences in Mg and CRP levels were observed between patients with AHI scores of 5-15 and scores ≥30 based on OSA severity but independent of BMI. Furthermore, the AHI, ODI, TST <90 %, and mean SpO2 significantly correlated with CRP. A significant negative correlation was observed between Mg and CRP levels (p < 0.0001). CONCLUSION: Our results show that Mg levels changed depending on the presence and severity of OSA. Low levels were associated with a higher CRP concentration in patients with OSA.

Serum Magnesium Level as a Biomarker to Predict the Risk of Labor Epidural Anesthesia Associated Fever.

Objective: Excessive pain will have adverse effects on the mother and fetus. Labor epidural analgesia greatly reduces the pain, which is widely carried out abroad. Labor epidural anesthesia-associated fever (LEAF) is the biggest problem for labor epidural anesthesia. This study aimed to evaluate the clinical value of serum magnesium levels to predict the LEAF. Methods: Overall 528 singleton term-pregnant women who underwent labor epidural anesthesia in Fujian Provincial Maternity and Children's Health Hospital, affiliated hospital of Fujian Medical University from January 2019 to June 2019, were analyzed retrospectively. The serum magnesium level was detected using venous blood samples. The relationship between the serum magnesium level and LEAF was interpreted, and the optimal cut-off values of the serum magnesium level to predict LEAF were calculated. Results: Overall, 65 (12.30%) participants had LEAF. And a higher rate of the bulging membrane, gestational hypertension, neonatal intensive care unit (NICU) admission, and the different mode of delivery was significantly associated with LEAF. Also, the serum magnesium level demonstrated higher significantly in presence of LEAF than absence (P<0.05). What is more, it indicated that the area under the receiver operating characteristic curve (AUC) for the serum magnesium level was 0.825, and an optimal cut-off of the serum magnesium level was 0.855 mg/dl. Furthermore, it demonstrated that the serum magnesium level had the highest OR (OR= 7.49; 95% CI (4.58-14.35)) (P<0.001). The bulging membrane is an independent risk factor presence of LEAF (OR = 1.55; 95% CI (1.01-2.43)) (P=0.038). Conclusion: This study demonstrated that the baseline of serum magnesium can provide a suitable biomarker to predict LEAF. It can help to provide a useful target for LEAF treatment and enhance surveillance before fever.

Magnesium-A More Important Role in CKD-MBD than We Thought.

Chronic kidney disease (CKD) is associated with different complications, including chronic kidney disease-mineral and bone disorder (CKD-MBD), which represents a systemic disorder that involves the presence of different mineral or bone structure abnormalities (i.e., modification of bone turnover, strength, volume, etc.), including even vascular calcification development. Even if, over the years, different pathophysiological theories have been developed to explain the onset and progression of CKD-MBD, the influence and importance of serum magnesium level on the evolution of CKD have only recently been highlighted. So far, data are inconclusive and conflicting; therefore, further studies are necessary to validate these findings, which could be useful in developing a better, more adequate, and personalized management of CKD patients.

The association between abnormal serum magnesium levels and prognosis of elderly patients with community-acquired pneumonia.

To investigate the association between abnormal serum magnesium levels and the prognosis of elderly patients with community-acquired pneumonia (CAP). Methods: A retrospective study was conducted on 1381 elderly patients with CAP in the First Hospital of Qinhuangdao between January 2015 and December 2018. Serum magnesium concentrations in the range of 0.75-1.25 mmol/L were defined as normal. Patients were assigned into normal, hypomagnesemia, and hypermagnesemia groups. The primary outcome was in-hospital mortality, indicating whether a patient died at the time of discharge from the hospital. The percentages of respiratory failure and mechanical ventilation were 18.6% and 10.6 % in the normal group, 29% and 16.5 % in the hypomagnesemia, and 42.9% and 35.7% in the hypermagnesemia groups. The occurrence of shock was 8.5% and 4.5% in the hypomagnesemia group and the normal group. The percentages of the length of stay at ICU were 14.9%, 18.8%, and 57.1% in the hypomagnesemia, normal, and hypermagnesemia groups. The in-hospital mortality rate was 5.3%, 9.1%, and 35.7% in the normal, hypomagnesemia, and hypermagnesemia groups, respectively. The results of univariate analysis showed that the in-hospital mortality in the hypomagnesemia group was 1.790 (95% confidence interval (CI): 1.009∼3.176, P=0.046) times higher than that in the normal group; in the hypermagnesemia group, it was 9.947 (95% CI: 3.238-30.556, P<0.001) times higher than that in the normal group. The results of multivariate logistic regression analysis showed that after adjusting for gender, age, diabetes, heart failure, cerebrovascular disease, cancer, estimated glomerular filtration rate (eGFR), glucose, and CURB-65 score, in the hypomagnesemia group, the in-hospital mortality was 1.746 (95% confidence interval (CI): 0.956∼3.186, P=0.070) times higher than that in the normal group, and 5.689 (95% CI: 1.583- 20.446, P=0.008) times higher in the hypermagnesemia group than that in the normal group. Abnormal serum magnesium levels are strongly associated with in-hospital mortality in elderly patients with CAP. The measurement of serum magnesium levels in elderly patients with CAP at admission may assist clinicians to determine the prognosis of such patients.

Serum magnesium and calcium levels in infertile women during a cycle of reproductive assistance.

Magnesium (Mg) and calcium (Ca) are essential cations for women's preconception health. It is well known that, in blood, the concentration of ionized form of these two cations is temporally altered during menstrual cycle, suggesting a correlation between sex steroid hormones and serum calcium and magnesium levels. Evidence from literature suggests that in assisted reproductive technology increasing estrogens during ovarian hyperstimulation may also modulate serum magnesium and calcium levels. Therefore, we first examined total serum magnesium and calcium levels during follicular phase in a large population of infertile patients who underwent intrauterine insemination (IUI). The results were compared to a group of fertile women. Successively, we studied the total serum magnesium and calcium concentrations in infertile patients before and after ovarian hyperstimulation for in vitro fertilization (IVF). Results highlight that total serum concentration of magnesium and calcium does not seem altered in infertile women. During stimulation with gonadotropins, the values of the two cations do not change significantly in ovarian-stimulated women. However, we found a downward trend in the total magnesium and calcium levels in relation to the rising estrogens.

The effect of an acute and 7-day administration of magnesium chloride on magnesium concentration in the serum, erythrocytes, and brain of rats.

BACKGROUND: Magnesium (Mg) is one of the most essential cations in human body that is involved in a variety of physiological processes. Despite the variations in the extracellular Mg level, specific transport systems are involved in maintaining the intracellular free Mg at a relatively constant level. We aimed to investigate the changes of Mg level in the brain, erythrocytes, and serum of rats after an acute and subchronic administration of Mg. METHODS: Magnesium chloride (MgCl2) solution was administered intraperitoneally (ip) either once at a dose of 50mg/kg or for 7 days at a single daily dose of 50mg/kg. Blood and brains of animals were collected 15, 30, 60, 120, and 240min after the acute or the last injection. Total Mg concentration in blood serum, erythrocytes, and the whole brain was determined spectrophotometrically. RESULTS: The highest Mg concentration was detected in the brain tissue, while the most significant changes in Mg level were found in serum. CONCLUSIONS: Neither the brain nor the erythrocyte showed a change in the Mg level considerably after an increase in serum Mg level induced by the acute and subchronic administration of MgCl2 solution.

Assessment of serum magnesium levels and its outcome in neonates of eclamptic mothers treated with low-dose magnesium sulfate regimen.

OBJECTIVES: Magnesium historically has been used for treatment and/or prevention of eclampsia. Considering the low body mass index of Indian women, a low-dose magnesium sulfate regime has been introduced by some authors. Increased blood levels of magnesium in neonates is associated with increased still birth, early neonatal death, birth asphyxia, bradycardia, hypotonia, gastrointestinal hypomotility. The objective of this study was to assess safety of low-dose magnesium sulfate regimen in neonates of eclamptic mothers treated with this regimen. MATERIALS AND METHODS: This was a cross-sectional observational study of 100 eclampsia patients and their neonates. Loading dose and maintenance doses of magnesium sulfate were administered to patients by combination of intravenous and intramuscular routes. Maternal serum and cord blood magnesium levels were estimated. Neonatal outcome was assessed. RESULTS: Bradycardia was observed in 18 (19.15%) of the neonates, 16 (17.02%) of the neonates were diagnosed with hypotonia. Pearson Correlation Coefficient showed Apgar scores decreased with increase in cord blood magnesium levels. Unpaired t-test showed lower Apgar scores with increasing dose of magnesium sulfate. The Chi-square/Fisher's exact test showed significant increase in hypotonia, birth asphyxia, intubation in delivery room, Neonatal Intensive Care Unit (NICU) care requirement, with increasing dose of magnesium sulfate. (P ≤ 0.05). CONCLUSION: Several neonatal complications are significantly related to increasing serum magnesium levels. Overall, the low-dose magnesium sulfate regimen was safe in the management of eclamptic mothers, without toxicity to their neonates.

Influence of mineral intake and use of oral contraceptives before pregnancy on the mineral content of human colostrum and of more mature milk.

PIP: The effects of mineral intake and long-term oral contraceptive use before pregnancy on the mineral content of milk of healthy lactating women were evaluated in a study of 52 volunteers ages 18-31. Subjects reporting previous oral contraceptive use had significantly lower levels of copper in serum, perhaps reflecting reduced copper stores resulting from prolonged estrogen exposure, but concomitant changes in copper levels in their milk were not noted. Serum calcium and magnesium levels were not significantly affected by prior pill use. Pill use had no significant effect on concentrations of calcium, magnesium, zinc, copper, or iron in colostrum at day 3 or more mature milk at day 14 of lactation, while mean manganese levels were significantly lower at both times for previous oral contraceptive users (but still exceeded manganese levels recommended for infants). Mineral and vitamin supplementation significantly improved the levels of zinc and iron intake, but did not appreciably alter the mineral content of milk. Higher levels of zinc were found in colostrum compared to day 14 milk, while manganese concentrations increased significantly during the 1st 2 weeks of lactation. Calcium, magnesium, iron and copper levels did not change significantly as lactation progressed. Levels of calcium, magnesium, zinc, copper, and manganese in colostrum were significantly positively correlated with the mineral concentration on day 14. No significant diurnal or daily variation was observed in the levels of calcium, magnesium, or zinc content in milk during 2 24-hour periods.^ieng

Vitamin B6 nutriture during pregnancy and lactation. I. Vitamin B6 intake, levels of the vitamin in biological fluids, and condition of the infant at birth.

Vitamin B6 nutriture was assessed during pregnancy and lactation to determine possible relationships among vitamin B6 intake, levels of the vitamin in biological fluids and the condition of the infant at birth. Vitamin B6 levels were measured in maternal serum and in urine at 5 and 7 months gestation and at delivery, in cord serum and in milk at 3 and 14 days postpartum. Intake of vitamin B6, less than the Recommended Dietary Allowances (1974) for pregnancy and lactation, 2.5 mg/day, resulted in lower levels of the vitamin in maternal serum at delivery and in cord serum than higher intakes. Mothers whose infants had unsatisfactory Apgar scores at 1 min, (less than 7) had significantly low intakes of vitamin B6 and lower levels of the vitamin in both serum and milk than mothers whose infants had satisfactory scores, (greater than or equal to 7). At 5 months gestation, levels of vitamin B6 in maternal serum were significantly correlated with levels of the vitamin in cord serum and in milk at 14 days postpartum. This stage of gestation precedes the period of rapid growth of the central nervous system of the fetus, and is, therefore, a critical time for the assessment of maternal vitamin B6 nutriture.

Convulsions in children.

PIP: Classification, management and prevention of seizures in children are summarized for clinicians in Papua New Guinea. Seizures are classified as febrile with or without underlying brain pathology, and afebrile, including neonatal fits, infantile spasms, myoclonic jerks, akinetic seizures, tonic clonic fits, petit mal, benign focal, and psychomotor seizures. In all cases the first step is to secure the airway, then do a fingerstick and treat hypoglycemia, and finally stop the fit if it is prolonged with paraldehyde, diazepam, phenobarbitone or phenytoin. A cause for the seizure should be sought: physical exam, especially tympanic membranes and throat, blood slide for malaria, lumbar puncture for signs of meningitis, blood culture, serum calcium, and other chemistries. Some empirical treatments to use for negative findings include: dextrose, calcium gluconate, magnesium SO4, pyridoxine, quinine and Fansidar. Hyperthermia in a febrile child can be reversed with cool sponging. The author recommends prescribing phenobarbitone to prevent subsequent simple febrile seizures if the child has 3 or more, then slowly withdrawing the drug if the child is seizure free for a year. Drug therapy for the various other types of seizures available in Papua New Guinea include sodium valproate by special order, and phenobarbitone, phenytoin, carbamazepine, nitrazepam, ethosuximide, and prednisolone. A table is provided to help select the drug for each seizure type, e.g. ethosuximide for petit mal, prednisolone for infantile spasms, and carbamazepine for various types of focal and psychomotor seizures.^ieng

[Behavior of serum magnesium level during abortion]. / Uber das Verhalten des Magnesiumspiegels des Blutes bei Abortus

Double determinations of whole blood- and serum magnesium levels were according to a complexometric method as described by Schwarzenbach (Hôlasek and Flaschka's procedure) in 134 females (66 healthy pregnant women, 68 abortions). Further, hematocrit was determined in these women. By aid of these values we were able to calculate Mg-concentrations/100 ml erythrocytes in all cases. Serum magnesium levels were depressed in the same relation in abortions and normal gravidae. Therefore, we do not confirm the results of other authors (22) asserting a typical significant decrease of serum-Mg in abortions. We warn against excessive differential-diagnostic interpretation of depressed serum magnesium in abortions. Magnesium concentrations in 100 ml erythrocytes were found significant increased over in abortions against women going through a successfully pregnancy. The cause of this magnesium increase is believed in reactive increased pouring out young partly immature erythrocytes containing high magnesium concentrations caused by losses of blood.

PIP: Whole blood and serum magnesium levels were determined in 66 healthy pregnant women and in 68 women with imminent, incipient, or incomplete abortions. Serum magnesium levels were equally depressed in abortion and in normal pregnancy, but magnesium concentrations per 100 ml erythrocytes were significantly higher in abortion patients. This finding is probably due to the increased release of immature erythrocytes with high magnesium concentrations to compensate for blood losses.

[Variations in blood magnesium in women according to age. Preliminary note]. / Variations de la magnesemie chez la femme en fonction de l'age. Note preliminaire.

PIP: Plasma and erythrocyte (RBC) magnesium levels were determined by atomic absorption spectrometry in 344 women aged 13-70 and in 209 men. The overall mean magnesium (Mg) contents were 52.8 mg/l in RBC's and 19.64 in plasma in women averaging 37.08 years, and 54.11 in RBC's and 20.38 in plasma in the men. When the women were grouped by age, those 13-20 years had the highest RBC and plasma Mg of all the cycling women. Those 23-24 years old had the lowest RBC Mg. The 65 menopausal women had significantly higher RBC Mg levels. Women over 45 had significantly higher plasma Mg than those 23-49 years. There were no variations with age in men, nor were there any relationships in women with cholesterolemia, weight, or height. Estrogens, 17-ketosteroids, or oral contraceptives may have caused low Mg levels in women.^ieng

Serum magnesium in women during pregnancy, while taking contraceptives, and after menopause.

Mean serum magnesium values with one standard deviation are presented for 224 women during pregnancy and 1559 women taking birth control pills, with 4145 women, aged 15-49 years, as controls. In addition, similar data are presented for 2,884 women, aged 50-74 years, after menopause. All these women were surveyed in the first National Health and Nutrition Examination Survey in the United States of America, 1971-1974 (NHANES I). Information on use of birth control pills is based on two questions taken from the NHANES I medical history interview. Pregnant women had significantly lower serum magnesium values than controls (nonpregnant and no birth control pills), regardless of age or race. Women on the pill also showed significantly lower serum magnesium values than other nonpregnant women of similar age, but the differences were much smaller than those between pregnant women and controls. Women older than 50 years (postmenopausal women) had significantly higher serum magnesium values than premenopausal women. These findings are compared with similar findings from other studies in the United States and other parts of the world.

Cervical dilatation by Lamicel--studies on the mechanism of action.

Lamicel is a synthetic hydrophilic polymer tent which produces cervical softening and dilatation when inserted into the endocervical canal. To investigate the mechanism of action of Lamicel, the intrauterine pressure and levels of 6-keto-prostaglandin F1 alpha, 13-14-dihydro-15-keto-prostaglandin F2 alpha, oestradiol and progesterone in plasma and amniotic fluid were measured in patients undergoing second trimester abortion. There was no significant change in any of the measured hormones during a 2-h treatment with Lamicel, but uterine activity increased significantly for 10 min after insertion, then settled spontaneously to below pre-treatment levels. Peripheral plasma levels of magnesium sulphate measured in patients undergoing first trimester abortion were not significantly raised after insertion of Lamicel. Light microscopic examination of cervical specimens, obtained at hysterectomy from patients pre-treated with Lamicel for 24 h, revealed minimum increase in vascularity, mast cell population and ground substance mucopolysaccharides.

PIP: Lamicel is a synthetic hydrophilic polymer tent which produces cervical softening and dilatation when inserted into the endocervical canal. To investigate the mechanism of action of Lamicel, the intrauterine pressure and levels of 6-keto-prostaglandin F2alpha (PGF2alpha), 13-14-dihydro-15-keto-PGF2alpha, estradiol, and progesterone in plasma and amniotic fluid were measured in patients undergoing 2nd trimester abortion. There was no significant change in any of the measured hormones during a 2 hour treatment with Lamicel, but uterine activity increased significantly for 10 minutes after insertion, then settled spontaneously to below pretreatment levels. Peripheral plasma levels of magnesium sulphate measured in patients undergoing 1st trimester abortion were not significantly raised after Lamicel insertion. Light microscopic examination of cervical specimens, obtained at hysterectomy from pretreated patients with Lamicel for 24 hours, revealed minimum increases in vascularity, mast cell population, and ground substance mucopolysaccharides.

Effect of oral contraceptives on Serum magnesium levels.

Serum magnesium levels were determined by atomic absorption apectrophotometry in 224 Nigerian women attending the post-partem Family Planning Clinic of University College Hospital, Ibadan. The concentrations of serum magnesium in 44 control subjects were similar to those of 87 women who had been fitted with the Lippes loop. Serum magnesium levels were significantly lower (P smaller than 0.001) in 28 women taking Ovral 28 and in 65 women taking Norlestrin Fe in comparison with the control group.

PIP: Considering the possibility that magnesium may be involved in the development of thromboembolism in humans, serum magnesium determinations were done in a group of 224 women attending the Post-Partum Family Planning Clinic of University College Hospital in Ibadan, Nigeria. Of these, 44 had been given no therapy, 87 had been fitted with Lippes loops, 28 were taking Ovral 28, and 65 were taking Norlestrin Fe. Those taking Ovral 28 had done so for an average of 9 months and those taking Norlestrin Fe, for 6 months. Magnesium concentrations were determined by atomic absorption spectrophotometry on serum deproteinized by a lanthanum-trichloroacetic acid diluent. Those fitted with Lippes loops had concentrations similar to the control group. Those taking the oral contraceptives had significantly lower levels (p less than .001) than the control group. Type of oral contraceptive or length of use was not correlated with serum magnesium levels. Results gave lower values than reported by others. In theory, the reduction in serum magnesium in women taking oral contraceptives would be associated with decreased clotting time and increased frequency of thromboembolic episodes.

[Serum levels of copper, iron, magnesium, calcium and zinc in women with a normal menstrual cycle, under treatment with oral hormonal contraceptives and in pregnancy]. / Das Verhalten von Kupfer, Eisen, Magnesium, Calcium und Zink bei Frauen mit normalem Menstruationscyclus, unter Einnahme von Ovulationshemmern und in der Gravidität.

PIP: Serum levels of copper, iron, magnesium, calcium, and zinc were studied in women with normal menstrual cycles, women taking Neogynon, Eugynon, and Lyndiol, and pregnant women. Levels in normal women were comparable with those previously reported. In women treated with ovulation inhibitors, zinc and calcium levels were lower, while copper, iron, and magnesium levels were higher. During pregnancy, zinc, iron, magnesium, and calcium levels decreased, while copper levels increased. Only zinc levels could be correlated with the phases of the menstrual cycle; the highest zinc levels during the normal cycle were found at the time of ovulation. Because of the wide range of variation, the results cannot be used as parameters for determining gestational age. The values of all cations may give relative information concerning gestational age, however.^ieng

Biochemical effects of oral contraceptives.

PIP: Literature on the biochemical effects of oral contraceptives (OCs) is reviewed. The effects of OCs on concentrations of mineral elements ( calcium, phosphorus, magnesium, iron, copper, and zinc), vitamins (ascor bic acid, folic acid, and Vitamins-B6, B12, and E), hormones, (gonadotro pins, progesterone, estrogens, androgens, corticosteroids, aldosterone, renin-angiotensin, insulin, growth hormone, thyroid hormones, catecholamines, and prolactin), amino acids and proteins (free amino acids, tryptophan, metalloproteins, hormone-binding proteins, miscellaneous serum proteins, and blood coagulation factors), carbohydra tes (glucose tolerance tests, glucose metablism and other carbohydrates) , lipids (total serum lipids, triglycerides, phospholipids, fatty acids, and cholesterol), and enzymes (aminotransfereases, alkaline phosphatase, and glutamyltransferase) are reviewed. Changes induced by combined, sequential, and low-dose OCs in 116 biochemical parameters are summarized in a table.^ieng