Magnesium research最新文献

Hypomagnesiuria is a common biochemical finding in patients with calcium oxalate (CaOx) nephrolithiasis. Clinical trials using Mg supplements as therapy against CaOx stones have shown mixed results. We tested the effect of Mg administration in healthy subjects under conditions of controlled urine pH (UpH) on urinary Ca excretion rate (UCaV) and CaOx saturation. This is a 4-phase, double blind, placebo-controlled, metabolic crossover study performed in healthy volunteers. Mg lactate (MgLact₂) was used as Mg supplement. High UpH and low UpH were achieved by administration of potassium citrate (K₃Citrate) and ammonium chloride (NH₄Cl), respectively, with potassium balance maintained by KCl. Eight participants completed 4 phases of study. The interventions successfully modulated 24-h UpH (7.0 ± 0.4 vs. 5.7 ± 0.6 in high vs low pH phases; P<0.001). Administration of MgLact₂ increased UMgV [175.8 ± 40.2 vs 93.4 ± 39.7 mg/day (7.2 ± 1.7 vs 3.8 ± 1.6 mmol/day), high vs low Mg phase; P<0.001], and increased pH both at low (5.6 ± 0.5 to 5.8 ± 0.7; P = 0.02) and high UpH (6.9 ± 0.4 to 7.0 ± 0.3; P = 0.01). At a given urine pH, Mg supplementation marginally increased UCaV, but did not alter UOxV or CaOx saturation. Provision of an alkali load significantly lowered UCaV and saturation of CaOx at any level of UMgV. Compared to changes in UMgV, changes in UpH play a more significant role in determining urine CaOx saturation in healthy subjects. Mg supplements are likely to reduce CaOx saturation if they also raise urine pH.

Magnesium is frequently used for pediatric migraine prophylaxis. The aim of this study was to evaluate to which extent the disability levels, quality of life (QOL), and anxiety and depressive symptoms change after 6-month magnesium prophylaxis in pediatric migraine. This is a follow-up study of 34 children aged 7-17 years with migraine treated with oral magnesium. Disability due to migraine was assessed by the Pediatric Migraine Disability Assessment tool (PedMIDAS), QOL was assessed by the KIDSCREEN-27, and anxiety and depressive symptoms were assessed by the Revised Child Anxiety and Depression Scale (RCADS). PedMIDAS scores significantly decreased from baseline to end-point (F(df, df_error) = 11.10 (1.63, 50.49), p<0.001), as well as anxiety (F(df, df_error) = 8.95 (1.64, 50.67), p = 0.001) and depressive symptoms (F(df, df_error) = 8.91 (1.59, 49.29), p = 0.001). Considering the KIDSCREEN-27, scores for physical and psychological well-being and social support domain significantly increased from baseline to end-point (p≤0.01). After 6 months of magnesium prophylaxis, disability due to migraine significantly decreased, whereas physical and psychosocial well-being improved. Children also reported fewer anxiety and depressive symptoms. More follow-up and randomized controlled clinical trials are needed to propose clinical recommendations for magnesium prophylaxis in pediatric migraine.

Increasing evidence supports a role of magnesium (Mg) in skeletal muscle function. However, no systematic review or meta-analysis has summarized data on Mg supplementation in relation to muscle fitness in humans. Thus, this study aimed to quantitatively assess the effect of Mg supplementation on muscle fitness. A meta-analysis and systematic review. Medline database and other sources were searched for randomized clinical trials through July 2017. Studies that reported results regarding at least one of the following outcomes: leg strength, knee extension strength, peak torque, muscle power, muscle work, jump, handgrip, bench press weights, resistant exercise, lean mass, muscle mass, muscle strength, walking speed, Repeated Chair Stands, and TGUG were included. Measurements of the association were pooled using a fixed-effects model and expressed as weighted mean differences (WMDs) with 95% confidence intervals (95% CIs). Fourteen randomized clinical trials targeting 3 different populations were identified: athletes or physically active individuals (215 participants; mean age: 24.9 years), untrained healthy individuals (95 participants; mean age: 40.2 years), and elderly or alcoholics (232 participants; mean age: 62.7 years). The beneficial effects of Mg supplementation appeared to be more pronounced in the elderly and alcoholics, but were not apparent in athletes and physically active individuals. The results of the meta-analysis suggested that no significant improvements in the supplementation group were observed regarding isokinetic peak torque extension [WMD = 0.87; 95% CI = (-1.43, 3.18)], muscle strength [WMD = 0.87; 95% CI = (-0.12, 1.86)] or muscle power [WMD = 3.28; 95% CI = (-14.94, 21.50)]. Evidence does not support a beneficial effect of Mg supplementation on muscle fitness in most athletes and physically active individuals who have a relatively high Mg status. But Mg supplementation may benefit individuals with Mg deficiency, such as the elderly and alcoholics.

The current study investigated whether adding magnesium to an NK1 tachykinin receptor antagonist after traumatic brain injury would enhance efficacy to further reduce blood-brain barrier permeability and improve functional recovery compared to either treatment alone. Sprague-Dawley rats were injured using the impact acceleration model of diffuse brain injury, and received either no treatment, MgSO₄ (30 mg/kg IV), the NK1 antagonist n-acetyl L tryptophan (2.5 mg/kg IP), or both agents combined. Animals were then killed at either 1, 5, or 24 h postinjury for determination of blood-brain barrier permeability using previously administered Evans blue dye or assessed for functional outcome over a 1-week period using the rotarod motor test. As expected, both MgSO₄ and n-acetyl L tryptophan significantly reduced blood-brain barrier permeability and improved functional outcome. However, combined n-acetyl L tryptophan and MgSO₄ was more effective at reducing blood-brain barrier permeability (P < 0.05) and improving functional outcome (P < 0.001) compared to the individual compounds. Our results demonstrate that combination therapy with magnesium and an NK1 antagonist may be a more effective therapy for TBI than either compound administered alone.

A stringent regulation of influx and efflux of magnesium by cation transporters seems to play an important role in the regulation of blood pressure (BP). With this regard, we evaluate the effect of oral magnesium supplementation on the transcription of TRPM6, TRPM7, and SLC41A1, in individuals with incident pre-hypertension (preHTN). For such purpose, we conducted a randomized, double-blind, placebo-controlled trial that compared 18 individuals who received oral magnesium lactate (360 mg elemental magnesium) versus 18 individuals who received placebo, during 4 months. Diagnosis of hypertension or normal BP, diabetes, alcohol intake, chronic diarrhea, use of diuretics, intake of magnesium supplementation, and reduced renal function were exclusion criteria. Regarding the transcription analysis of TRPM6, TRPM7, and SLC41A1 using RT-qPCR, leukocyte-rich plasma was obtained and total RNA was isolated with the kit Direct-zol™ RNA MiniPrep (Zymo). The leukocyte TRPM6 mRNA relative expression showed a significant increase (2.1 ± 1.37 and 0.8 ± 0.4, P<0.05), whereas the mRNA relative expression of both leukocyte TRPM7 (0.8 ± 1.1 and 0.9 ± 0.6, pNS) and SLC41A1 (0.9 ± 1.0 and 0.7 ± 0.6, pNS) showed no significant differences, between the magnesium and placebo groups, respectively. Oral magnesium supplementation increases the leukocyte TRPM6 mRNA relative expression, in subjects with new diagnosis of preHTN.

Hepatocyte nuclear factor 1β (HNF1β) is a transcription factor that is involved in embryonic development and tissue-specific gene expression in several organs, including the kidney and the liver. HNF1β mutations are associated with hypomagnesemia and renal magnesium wasting; however, to date, the exact molecular mechanism involved in this regulation is unclear. Furthermore, it is not known whether the Mg concentration could per se participate to this regulation by modifying HNF1β expression. We have studied in rats the effects of a 6-week diet with deficient or supplemented Mg concentrations compared to a diet with a standard Mg concentration on HNF1β protein expression. HNF1β expression was increased in the Mg-deficient group as compared to the other groups in the liver but not in the kidney. No changes in tissue Mg level were obtained in both organs. By contrast, a significant correlation between plasma Mg concentration and HNF1β level in the rat liver was evidenced. In rat hepatocyte cultures exposed for 72h to various extracellular Mg concentrations, HNF1β expression was modified after 72h of treatment of the hepatocytes with the lowest Mg concentrations as compared to the other Mg conditions. Moreover, these changes were correlated with extracellular but not intracellular Mg concentrations. In conclusion, HNF1β expression is modified by the extracellular Mg concentration in the liver, both in vivo and in vitro, suggesting regulations with membrane events in hepatocytes.

Magnesium is known to exert several beneficial effects, including antiglycemic and antilipidemic properties. The aim of this study was to evaluate the effects of magnesium supplementation on gene expression related to insulin and lipid metabolism in women with gestational diabetes (GDM) who were not on oral hypoglycemic agents. This randomized double-blind, placebo-controlled trial was conducted among 40 patients diagnosed with GDM, aged 18-40 years. Participants were randomly allocated into two groups to take either 250 mg/day of magnesium supplements in the form of magnesium oxide (n = 20) or placebo (n = 20) for 6 weeks. Gene expression related to insulin and lipid metabolism was assessed in peripheral blood mononuclear cells (PBMCs) of women with GDM using RT-PCR method. Compared with the placebo, magnesium supplementation to women with GDM resulted in a significant decrease in levels of fasting plasma glucose (FPG) (-9.7 ± 5.6 vs. -0.1 ± 8.5 mg/dL, P<0.001). Quantitative results of RT-PCR demonstrated that compared with the placebo, magnesium supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (P = 0.003) and glucose transporter 1 (GLUT-1) (P = 0.004) and downregulated gene expression of oxidized low-density lipoprotein receptor (LDLR) (P = 0.001) in PBMCs of women with GDM. In addition, a trend toward a greater decrease in gene expression of lipoprotein (a) [LP(a)] was observed in the patients belonging to magnesium group compared to placebo group (P = 0.08). Overall, magnesium supplementation for 6 weeks in women with GDM significantly improved FPG levels, and gene expression of PPAR-γ, GLUT-1, and LDLR.

Previous studies have indicated diabetes was associated with lower serum magnesium (Mg) level. Patients with renal impairment usually have higher Mg concentration due to reduced renal excretion. Whether Mg level in diabetics with chronic kidney disease (CKD) is altered remains undermined. In this study, we analyzed serum Mg concentration in patients with CKD and also compared diabetics with non-diabetics. Factors associated with Mg levels were explored. A total of 939 patients were included and 717 were with CKD. Their serum Mg concentration increased progressively, as their glomerular filtration rate (GFR) decreased in both diabetics and non-diabetics. Compared with non-diabetics, diabetes was significantly associated with lower serum Mg concentration in patients without CKD than in patients with CKD in all stages of disease. Multivariate regression analysis identified that both diabetes and serum albumin were independent factors of serum Mg concentration in patients without CKD. Age, diabetes, serum albumin concentration, GFR and macroproteinuria were significantly associated with serum Mg concentration in patients with early-stage CKD. In patients with moderate-to-severe CKD, diabetes, serum albumin and GFR were independent factors related to the serum Mg level.

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.