Effects of long-term magnesium supplementation on endothelial function and cardiometabolic risk markers: A randomized controlled trial in overweight/obese adults

Therapeutic Options for Migraines in the Microsurgical Patient: A Scoping Review

BACKGROUND

There exists an increasing array of treatments proposed to prevent, alleviate, and abort symptoms of a migraine; however, for patients who undergo reconstructive microsurgery, caution must be taken to preserve vascular integrity. This study is the first-to-date scoping review of vascular and bleeding risk of current migraine therapies, with the purpose of identifying potential therapeutic agents for postoperative migraine management appropriate for microsurgical patients.

METHODS

Currently available migraine therapeutics were compiled from the UpToDate software system and the American Academy of Family Physicians. A PubMed literature review was performed for each therapeutic's effect on bleeding or vascular involvement. Data were compiled into tables of abortive, symptom-controlling and prophylactic, and nonpharmacologic treatments. Expert microsurgeons reviewed the data to provide recommendations for optimized patient care.

RESULTS

Triptans and other ergot derivatives demonstrated strong evidence of vasoconstriction and were greatly advised against for immediate postmicrosurgical use. Novel pharmaceutical therapies such as lasmiditan and calcitonin gene-related peptide antagonists have no literature indicating potential for vasoconstriction or hematoma and remain an investigational option for abortive medical treatment. For symptom control, acetaminophen appears the safest option, with clinical judgment and further research needed for use of nonsteroidal antiinflammatory drugs. Alternative treatment techniques may include migraine prophylaxis with botulinum toxin injection or nutraceutical treatment by means of magnesium supplementation or coenzyme Q10 administration, minimizing the need for additional medication in the postoperative setting.

CONCLUSIONS

Patients undergoing reconstructive microsurgery have a unique medical profile limiting the therapeutic options available to treat migraines. This review provides preliminary evidence to be considered as a guide for prescribing therapeutics for migraine in the postoperative setting.

Magnesium Deficiency and Cardiometabolic Disease

Magnesium (Mg²⁺) has many physiological functions within the body. These include important roles in maintaining cardiovascular functioning, where it contributes to the regulation of cardiac excitation-contraction coupling, endothelial functioning and haemostasis. The haemostatic roles of Mg²⁺ impact upon both the protein and cellular arms of coagulation. In this review, we examine how Mg²⁺ homeostasis is maintained within the body and highlight the various molecular roles attributed to Mg²⁺ in the cardiovascular system. In addition, we describe how nutritional and/or disease-associated magnesium deficiency, seen in some metabolic conditions, has the potential to influence cardiac and vascular outcomes. Finally, we also examine the potential for magnesium supplements to be employed in the prevention and treatment of cardiovascular disorders and in the management of cardiometabolic health.

Combined vitamin D and magnesium supplementation does not influence markers of bone turnover or glycemic control: A randomized controlled clinical trial

High-dose vitamin D supplementation can increase total osteocalcin concentrations that may reduce insulin resistance in individuals at risk for prediabetes or diabetes mellitus. Magnesium is a cofactor in vitamin D metabolism and activation. The purpose of this study was to determine the combined effect of vitamin D and magnesium supplementation on total osteocalcin concentrations, glycemic indices, and other bone turnover markers after a 12-week intervention in individuals who were overweight and obese, but otherwise healthy. We hypothesized that combined supplementation would improve serum total osteocalcin concentrations and glycemic indices more than vitamin D supplementation alone or a placebo. A total of 78 women and men completed this intervention in 3 groups: a vitamin D and magnesium group (1000 IU vitamin D₃ and 360 mg magnesium glycinate), a vitamin D group (1000 IU vitamin D₃), and a placebo group. Despite a significant increase in serum 25-hydroxyvitamin D concentrations in the vitamin D and magnesium group compared with the placebo group (difference = 5.63; CI, -10.0 to -1.21; P = .001) post-intervention, there were no differences in serum concentrations of total osteocalcin, glucose, insulin, and adiponectin or the homeostatic model assessment of insulin resistance (HOMA-IR) among groups (P > .05 for all). Additionally, total osteocalcin (β = -0.310, P = .081), bone-specific alkaline phosphatase (β = 0.004, P = .986), and C-terminal cross-linked telopeptide (β = 0.426, P = .057), were not significant predictors of HOMA-IR after the intervention. Combined supplementation was not associated with short-term improvements in glycemic indices or bone turnover markers in participants who were overweight and obese in our study. This trial was registered at clinicaltrials.gov (NCT03134417).

The Significance of Low Magnesium Levels in COVID-19 Patients

Magnesium is the fourth most common mineral in the human body and the second richest intracellular cation. This element is necessary for many physiological reactions, especially in the cardiovascular and respiratory systems. COVID-19 is an infectious disease caused by SARS-CoV-2. The majority of people who become ill as a result of COVID-19 have mild-to-moderate symptoms and recover without specific treatment. Moreover, there are people who develop severe forms of COVID-19, which require highly specialized medical assistance. Magnesium deficiency may play a role in the pathophysiology of infection with SARS-CoV-2. The primary manifestation of COVID-19 remains respiratory, but the virus can spread to other organs and tissues, complicating the clinical picture and culminating in multiorgan failure. The key mechanisms involved in the disease include direct viral cytotoxicity, endothelial dysfunction, and exaggerated release of inflammatory cytokines. The aim of this review was to summarize the available data regarding the role of magnesium in COVID-19 patients and its particularities in different clinical settings.

Magnesium Supplementation Affects the Expression of Sirtuin1, Tumor Protein P53 and Endothelial Nitric Oxide Synthase Genes in Patients with Atherosclerosis: A Double-Blind, Randomized, Placebo-Controlled Trial

Magnesium seems to play a role in improving cardiovascular function, but its exact mechanism is unknown. In this study, we hypothesized that magnesium could modulate the expression of genes involved in atherosclerosis. The aim of the present investigation was to evaluate the effect of magnesium sulfate on the expression of sirtuin1 (SIRT1), tumor protein p53 (TP53), and endothelial nitric oxide synthase (eNOS) genes in patients with atherosclerosis. This study was a placebo-controlled double-blind randomized clinical trial on 56 patients with angiographically proven atherosclerosis. Participants were randomly divided into two groups receiving 300 mg/day magnesium sulfate (n = 29) and placebo (n = 27) for three months (following up every month). Fasting blood samples were taken before and after the intervention and total RNA was extracted and used to evaluate the expression level of SIRT1, TP53, and eNOS genes by Real-Time PCR. The expression of eNOS gene was significantly increased (P < 0.0001) and the expression of TP53 gene was decreased (P = 0.02) in the magnesium sulfate group compared to the placebo group. But SIRT1 gene expression was not significantly different between the two groups. Our findings demonstrate that magnesium sulfate supplementation may have a protective role against the progression of atherosclerosis through upregulation of eNOS and downregulation of TP53 gene. Trial registration: This present clinical trial has been registered in the Iranian Registry of Clinical Trials (IRCT) with the registration code of "IRCT20151028024756N3", https://www.irct.ir/trial/29097?revision=114102. Registered on 16 December 2019.

Nutritional supplements improve cardiovascular risk factors in overweight and obese patients: A Bayesian network meta-analysis

Background

Overweight and obesity are considered as one of the major risk factors for cardiovascular diseases (CVD). At present, many studies have proved that multiple nutritional supplements play an active role in metabolic diseases. However, the comparative efficacy of different nutritional supplements in improving indicators of cardiometabolic risk in obese and overweight patients is uncertain.

Methods

Cochrane Library, PubMed, Embase, and Web of Science were searched for the period from January 1990 to March 2022. A random-effect model was built in the Bayesian network meta-analysis. The surface under the cumulative ranking analysis (SUCRA) and clustering rank analysis was performed for ranking the effects.

Results

The study included 65 RCTs with 4,241 patients. In terms of glucose control, probiotic was more conductive to improve FBG (MD: -0.90; 95%CrI: -1.41 to -0.38), FINS (MD: -2.05; 95%CrI: -4.27 to -0.02), HOMA-IR (MD: -2.59; 95%CI -3.42 to -1.76). Probiotic (MD: -11.15, 95%CrI -22.16 to -1.26), omega-3 (MD: -9.45; 95%CrI: -20.69 to -0.93), VD (MD: -17.86; 95%CrI: -35.53 to -0.27), and probiotic +omega-3 (MD: 5.24; 95%CrI: 0.78 to 9.63) were beneficial to the improvement of TGs, TC and HDL-C, respectively. The SUCRA revealed that probiotic might be the best intervention to reduce FBG, FINS, HOMA-IR; Simultaneously, α-lipoic acid, VD, and probiotic + omega-3 might be the best intervention to improve TGs, TC, and HDL-C, respectively. Cluster-rank results revealed probiotic had the best comprehensive improvement effect on glucose metabolism, and probiotic + omega-3 may have a better comprehensive improvement effect on lipid metabolism (cluster-rank value for FBG and FINS: 3290.50 and for TGs and HDL-C: 2117.61).

Conclusion

Nutritional supplementation is effective on CVD risk factors in overweight and obese patients. Probiotic supplementation might be the best intervention for blood glucose control; VD, probiotic + omega-3 have a better impact on improving lipid metabolism. Further studies are required to verify the current findings.

Effect of oral magnesium supplement on cardiometabolic markers in people with prediabetes: a double blind randomized controlled clinical trial

To evaluate the effect of magnesium supplementation on insulin resistance and cardiovascular markers in people with prediabetes. A 12 week double-blind placebo-controlled randomized clinical trial was conducted at Isfahan Endocrine and Metabolism Research Center, Iran, on people with prediabetes (n = 86) to compare the effects of magnesium oxide 250 mg/day versus a placebo on anthropometric indices, blood pressure, fasting glucose, insulin, HOMA-IR index, C-reactive protein, uric acid and lipid profile. Both groups had similar distributions of anthropometric and biochemical variables at baseline. Those who received magnesium supplementation had significantly higher levels of HDL-cholesterol compared to the placebo group at the end of the study (49.7 ± 10.9 vs 43.6 ± 7.2 mg/dL, P = 0.003). The mean changes of HOMA-IR index, total cholesterol, LDL-cholesterol, triglyceride, uric acid and C-reactive protein levels as well as anthropometric indices and blood pressure in supplemented and placebo groups did not differ significantly. Magnesium supplementation increased HDL-cholesterol levels in people with prediabetes. However, other cardiometabolic markers were not improved by magnesium supplementation at the above dosage and duration.

The Effect of Oral Magnesium Supplementation on Inflammatory Biomarkers in Adults: A Comprehensive Systematic Review and Dose-response Meta-analysis of Randomized Clinical Trials

This is a comprehensive systematic review and dose-response meta-analysis evaluating the effects of oral magnesium supplementation on inflammatory biomarkers including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adults. The major databases including PubMed, Web of Science, Embase, and Google Scholar were searched for relevant publications until December 14, 2020, using appropriate keywords. The Cochrane Collaboration tool was used to assess the quality of each study. We also performed a subgroup analysis to identify probable sources of heterogeneity. A total of 18 studies with 927 participants fulfilled the eligibility criteria and included in this meta-analysis. Our results indicate that the supplementation with magnesium had no statistically significant effect on serum concentrations of CRP (WMD, - 0.49; 95% CI, - 1.72 to 0.75 mg/L; P = 0.44), IL-6 (WMD, - 0.03; 95% CI, - 0.40 to 0.33 pg/mL; P = 0.86), and TNF-α (WMD, 0.12; 95% CI, - 0.08 to 0.31 pg/mL; P = 0.24) compared with controls. In addition, based on dose-response assessment, no significant non-linear association was found between magnesium supplementation dosage or duration on serum CRP and IL-6 concentrations. The findings of the present systematic review and meta-analysis did not support the notion that oral magnesium supplementation could have favorable effects on CRP, IL-6, and TNF-α in the adult population.

Effect of Magnesium Supplementation on Inflammatory Parameters: A Meta-Analysis of Randomized Controlled Trials

Magnesium (Mg) may have several beneficial effects on human health outcomes. One hypothesized mechanism eliciting such effects is the action of Mg on serum inflammatory parameters. However, studies on this topic to date have several important limitations. Therefore, the present systematic review and meta-analysis aimed to summarize the current state of the art of all randomized control trials (RCTs) investigating the effects of Mg supplementation versus placebo on serum parameters of inflammation. We searched several databases until 23 November 2021 for RCTs. Eligible studies were RCTs investigating the effect of oral Mg supplementation vs. placebo and having serum inflammatory markers as an outcome. Among 2484 papers initially screened, 17 randomized controlled trials (889 participants; mean age: 46 years; females: 62.5%) were included. Generally, a low risk of bias was present. In meta-analysis, Mg supplementation significantly decreased serum C reactive protein (CRP) and increased nitric oxide (NO) levels. In descriptive findings, Mg supplementation significantly reduced plasma fibrinogen, tartrate-resistant acid phosphatase type 5, tumor necrosis factor-ligand superfamily member 13B, ST2 protein, and IL-1. In conclusion, Mg supplementation may significantly reduce different human inflammatory markers, in particular serum CRP and NO levels.

Oral Magnesium Supplementation for Treating Glucose Metabolism Parameters in People with or at Risk of Diabetes: A Systematic Review and Meta-Analysis of Double-Blind Randomized Controlled Trials

There is a large and growing body of literature focusing on the use of oral magnesium (Mg) supplementation for improving glucose metabolism in people with or at risk of diabetes. We therefore aimed to investigate the effect of oral Mg supplementation on glucose and insulin-sensitivity parameters in participants with diabetes or at high risk of diabetes, compared with a placebo. Several databases were searched investigating the effect of oral Mg supplementation vs placebo in patients with diabetes or conditions at high risk of diabetes. Data were reported as standardized mean differences (SMDs) with their 95% confidence intervals (CIs) using follow-up data of glucose and insulin-sensitivity parameters. Compared with placebo, Mg supplementation reduced fasting plasma glucose in people with diabetes. In people at high risk of diabetes, Mg supplementation significantly improved plasma glucose per se, and after a 2 h oral glucose tolerance test. Furthermore, Mg supplementation demonstrated an improvement in insulin sensitivity markers. In conclusion, Mg supplementation appears to have a beneficial role and improves glucose parameters in people with diabetes. Moreover, our work indicates that Mg supplementation may improve insulin-sensitivity parameters in those at high risk of diabetes.

Cross-Talks between the Cardiovascular Disease-Sarcopenia-Osteoporosis Triad and Magnesium in Humans

Magnesium (Mg) is a pivotal and very complex component of healthy aging in the cardiovascular-muscle-bone triad. Low Mg levels and low Mg intake are common in the general aging population and are associated with poorer outcomes than higher levels, including vascular calcification, endothelial dysfunction, osteoporosis, or muscle dysfunction/sarcopenia. While Mg supplementation appears to reverse these processes and benefit the triad, more randomized clinical trials are needed. These will allow improvement of preventive and curative strategies and propose guidelines regarding the pharmaceutical forms and the dosages and durations of treatment in order to optimize and adapt Mg prescription for healthy aging and for older vulnerable persons with comorbidities.

The Effect of Magnesium Supplementation on Endothelial Function: A Randomised Cross-Over Pilot Study

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24 h urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005, respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = −0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.

The Acute Effect of Magnesium Supplementation on Endothelial Function: A Randomized Cross-Over Pilot Study

Magnesium (Mg) deficiency might be a catalyst in the process of endothelial dysfunction, an early event in the pathogenesis of atherosclerosis. The aim of this study was to determine the acute effect of an oral Mg supplement as compared to control on endothelial function assessed by flow-mediated dilatation (FMD). Nineteen participants (39 years, body mass index (BMI) 22.9 kg/m²) completed this randomized cross-over study. Blood pressure (BP) and FMD were measured and blood samples were taken before participants drank 200 mL water, with or without an over the counter Mg supplement (450 mg and 300 mg for men and women). Measurements were repeated at 60 and 120 min. There was a statistically significant two-way interaction between treatment and time on serum Mg (p = 0.037). A difference of −0.085 mm in FMD was observed 60-min post drink in the control group, as compared to baseline FMD, and no difference was observed in the supplement group as compared to baseline. Despite the non-significant interaction between treatment and time on FMD, once adjusted for baseline, the difference seen in the control group and the lack of change in the supplement group at 60 min post-drink suggests that Mg might attenuate the reduction in FMD post-prandially.

Crosstalk of Magnesium and Serum Lipids in Dyslipidemia and Associated Disorders: A Systematic Review

Dyslipidemia is a significant threat to public health worldwide and the identification of its pathogenic mechanisms, as well as novel lipid-lowering agents, are warranted. Magnesium (Mg) is a key element to human health and its deficiency has been linked to the development of lipid abnormalities and related disorders, such as the metabolic syndrome, type 2 diabetes mellitus, or cardiovascular disease. In this review, we explored the associations of Mg (dietary intake, Mg concentrations in the body) and the lipid profile, as well as the impact of Mg supplementation on serum lipids. A systematic search was computed in PubMed/MEDLINE and the Cochrane Library and 3649 potentially relevant papers were detected and screened (n = 3364 following the removal of duplicates). After the removal of irrelevant manuscripts based on the screening of their titles and abstracts (n = 3037), we examined the full-texts of 327 original papers. Finally, after we applied the exclusion and inclusion criteria, a number of 124 original articles were included in this review. Overall, the data analyzed in this review point out an association of Mg concentrations in the body with serum lipids in dyslipidemia and related disorders. However, further research is warranted to clarify whether a higher intake of Mg from the diet or via supplements can influence the lipid profile and exert lipid-lowering actions.

Long-term magnesium supplementation improves glucocorticoid metabolism: A post-hoc analysis of an intervention trial

OBJECTIVE

Increasing magnesium intake might reduce the risk of cardiovascular disease (CVD). Whether potential effects on cortisol contribute to these beneficial effects on cardiovascular health remains unclear. We therefore studied effects of long-term oral magnesium supplementation on glucocorticoid metabolism, specifically on the excretion of urinary cortisol, cortisone and their metabolites, as well as on the ratios reflecting enzymatic activity of 11β-hydroxysteroid dehydrogenases (11β-HSDs) and A-ring reductases.

DESIGN

A post-hoc analysis of a randomized trial with allocation to a magnesium supplement (350 mg/day) or a placebo for 24-week.

PATIENTS

Forty-nine overweight men and women, aged between 45 and 70 years.

MEASUREMENTS

Cortisol, cortisone and their metabolites (tetrahydrocortisol [THF], allo-tetrahydrocortisol [allo-THF] and tetrahydrocortisone [THE]) were measured in 24-h urine samples. Enzymatic activities of 11β-HSD overall and of 11β-HSD type 2 were estimated as the urinary (THF + allo-THF [THFs])/THE and cortisol/cortisone ratios, respectively. A-ring reductase activity was assessed by ratios of THF/allo-THF, allo-THF/cortisol, THF/cortisol and THE/cortisone.

RESULTS

After 24-week, urinary cortisol excretion was decreased in the magnesium group as compared with the placebo group (-32 nmol/24-h, 95% CI: -59; -5 nmol/24-h, p = .021). Ratios of THFs/THE and cortisol/cortisone were decreased following magnesium supplementation by 0.09 (95% CI: 0.02; 0.17, p = .018) and 0.10 (95% CI: 0.03; 0.17, p = .005), respectively. No effects were observed on A-ring reductase activity.

CONCLUSIONS

We observed a beneficial effect of magnesium supplementation towards a lower 24-h urinary cortisol excretion together with an increased activity of 11β-HSD type 2. Our findings may provide another potential mechanism by which increased magnesium intake lowers CVD risk (ClinicalTrials.gov identifier: NCT02235805).

Magnesium in Obesity, Metabolic Syndrome, and Type 2 Diabetes

Magnesium (Mg²⁺) deficiency is probably the most underestimated electrolyte imbalance in Western countries. It is frequent in obese patients, subjects with type-2 diabetes and metabolic syndrome, both in adulthood and in childhood. This narrative review aims to offer insights into the pathophysiological mechanisms linking Mg²⁺ deficiency with obesity and the risk of developing metabolic syndrome and type 2 diabetes. Literature highlights critical issues about the treatment of Mg²⁺ deficiency, such as the lack of a clear definition of Mg²⁺ nutritional status, the use of different Mg²⁺ salts and dosage and the different duration of the Mg²⁺ supplementation. Despite the lack of agreement, an appropriate dietary pattern, including the right intake of Mg²⁺, improves metabolic syndrome by reducing blood pressure, hyperglycemia, and hypertriglyceridemia. This occurs through the modulation of gene expression and proteomic profile as well as through a positive influence on the composition of the intestinal microbiota and the metabolism of vitamins B1 and D.

The Role of Disturbed Mg Homeostasis in Chronic Kidney Disease Comorbidities

Some of the critical mechanisms that mediate chronic kidney disease (CKD) progression are associated with vascular calcifications, disbalance of mineral metabolism, increased oxidative and metabolic stress, inflammation, coagulation abnormalities, endothelial dysfunction, or accumulation of uremic toxins. Also, it is widely accepted that pathologies with a strong influence in CKD progression are diabetes, hypertension, and cardiovascular disease (CVD). A disbalance in magnesium (Mg) homeostasis, more specifically hypomagnesemia, is associated with the development and progression of the comorbidities mentioned above, and some mechanisms might explain why low serum Mg is associated with negative clinical outcomes such as major adverse cardiovascular and renal events. Furthermore, it is likely that hypomagnesemia causes the release of inflammatory cytokines and C-reactive protein and promotes insulin resistance. Animal models have shown that Mg supplementation reverses vascular calcifications; thus, clinicians have focused on the potential benefits that Mg supplementation may have in humans. Recent evidence suggests that Mg reduces coronary artery calcifications and facilitates peripheral vasodilation. Mg may reduce vascular calcification by direct inhibition of the Wnt/β-catenin signaling pathway. Furthermore, Mg deficiency worsens kidney injury induced by an increased tubular load of phosphate. One important consequence of excessive tubular load of phosphate is the reduction of renal tubule expression of α-Klotho in moderate CKD. Low Mg levels worsen the reduction of Klotho induced by the tubular load of phosphate. Evidence to support clinical translation is yet insufficient, and more clinical studies are required to claim enough evidence for decision-making in daily practice. Meanwhile, it seems reasonable to prevent and treat Mg deficiency. This review aims to summarize the current understanding of Mg homeostasis, the potential mechanisms that may mediate the effect of Mg deficiency on CKD progression, CVD, and mortality.

A Review of the Action of Magnesium on Several Processes Involved in the Modulation of Hematopoiesis

Magnesium (Mg²⁺) is an essential mineral for the functioning and maintenance of the body. Disturbances in Mg²⁺ intracellular homeostasis result in cell-membrane modification, an increase in oxidative stress, alteration in the proliferation mechanism, differentiation, and apoptosis. Mg²⁺ deficiency often results in inflammation, with activation of inflammatory pathways and increased production of proinflammatory cytokines by immune cells. Immune cells and others that make up the blood system are from hematopoietic tissue in the bone marrow. The hematopoietic tissue is a tissue with high indices of renovation, and Mg²⁺ has a pivotal role in the cell replication process, as well as DNA and RNA synthesis. However, the impact of the intra- and extracellular disturbance of Mg²⁺ homeostasis on the hematopoietic tissue is little explored. This review deals specifically with the physiological requirements of Mg²⁺ on hematopoiesis, showing various studies related to the physiological requirements and the effects of deficiency or excess of this mineral on the hematopoiesis regulation, as well as on the specific process of erythropoiesis, granulopoiesis, lymphopoiesis, and thrombopoiesis. The literature selected includes studies in vitro, in animal models, and in humans, giving details about the impact that alterations of Mg²⁺ homeostasis can have on hematopoietic cells and hematopoietic tissue.

Effect of Magnesium Supplementation on Circulating Biomarkers of Cardiovascular Disease

(1) Background: Magnesium supplementation may be effective for the prevention of cardiometabolic diseases, but the mechanisms are unclear. Proteomic approaches can assist in identifying the underlying mechanisms. (2) Methods: We collected repeated blood samples from 52 individuals enrolled in a double-blind trial which randomized participants 1:1 to oral magnesium supplementation (400 mg magnesium/day in the form of magnesium oxide) or a matching placebo for 10 weeks. Plasma levels of 91 proteins were measured at baseline with follow-up samples using the Olink Cardiovascular Disease III proximity extension assay panel and were modeled as arbitrary units in a log₂ scale. We evaluated the effect of oral magnesium supplementation for changes in protein levels and the baseline association between serum magnesium and protein levels. The Holm procedure was used to adjust for multiple comparisons. (3) Results: Participants were 73% women, 94% white, and had a mean age of 62. Changes in proteins did not significantly differ between the two intervention groups after correction for multiple comparisons. The most statistically significant effects were on myoglobin [difference −0.319 log₂ units, 95% confidence interval (CI) (−0.550, −0.088), p = 0.008], tartrate-resistant acid phosphatase type 5 (−0.187, (−0.328, −0.045), p = 0.011), tumor necrosis factor ligand superfamily member 13B (−0.181, (−0.332, −0.031), p = 0.019), ST2 protein (−0.198, (−0.363, −0.032), p = 0.020), and interleukin-1 receptor type 1 (−0.144, (−0.273, −0.015), p = 0.029). Similarly, none of the associations of baseline serum magnesium with protein levels were significant after correction for multiple comparisons. (4) Conclusions: Although we did not identify statistically significant effects of oral magnesium supplementation in this relatively small study, this study demonstrates the value of proteomic approaches for the investigation of mechanisms underlying the beneficial effects of magnesium supplementation. Clinical Trials Registration: ClinicalTrials.gov NCT02837328.

Effects of Oral Magnesium Supplementation on Vascular Function: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The effects of magnesium (Mg) supplementation on vascular function have been evaluated in some randomized controlled trials (RCT) but their results are conflicting.

AIM

A systematic review and meta-analysis were conducted to summarize the effects of oral Mg supplementation on vascular function in RCT.

METHODS

The databases MEDLINE (PubMed), Embase, Web of Science and Cochrane Library were accessed from inception to May 27, 2019. Intergroup differences (treatment vs. control group) related to changes in flow-mediated dilation (FMD) and pulse wave velocity (PWV), expressed as mean and standard deviation, were used to evaluate the effect of Mg supplementation on these outcomes. The results of the meta-analysis were expressed using a random-effects model. The heterogeneity between studies was evaluated using the I² statistic.

RESULTS

The oral supplementation of Mg had no significant effect on FMD (mean difference 2.13; 95% CI - 0.56, 4.82; p = 0.12) and PWV (mean difference - 0.54, 95% CI - 1.45, 0.36, p = 0.24). Heterogeneity for both outcomes (FMD and PWV) was high (I² = 99%, p < 0.001). However, in subgroup analyses, oral Mg significantly improved FMD in studies longer than 6 months, in unhealthy subjects, in individuals older than 50 years, or in those with body mass index (BMI) ≥ 25 kg/m². The reduced number of RCT and the heterogeneity among them were the main limitations.

CONCLUSIONS

This meta-analysis suggest that oral Mg supplementation may improve endothelial function when conducted at least for 6 months and in unhealthy, overweight or older individuals. Registration number: PROSPERO CRD42019111462.

Effect of α-linolenic acid on vascular function and metabolic risk markers during the fasting and postprandial phase: A randomized placebo-controlled trial in untreated (pre-)hypertensive individuals

BACKGROUND

Only a limited number of studies have examined the vascular and postprandial effects of α-linolenic acid (ALA, C18:3n-3). Therefore, we performed a well-controlled trial focusing specifically on the effects of ALA on vascular function and metabolic risk markers during the fasting and postprandial phase in untreated (pre-)hypertensive individuals.

METHODS

In a double-blind randomized, placebo-controlled parallel study, 59 overweight and obese adults (40 men and 19 women, aged 60 ± 8 years) with a high-normal blood pressure or mild (stage I) hypertension consumed daily either 10 g of refined cold-pressed flaxseed oil, providing 4.7 g ALA (n = 29), or 10 g of high-oleic sunflower (control) oil (n = 30) for 12 weeks.

RESULTS

As compared with the high-oleic oil control, intake of flaxseed oil did not change brachial artery flow-mediated vasodilation, carotid-to-femoral pulse wave velocity, retinal microvascular calibers and plasma markers of microvascular endothelial function during the fasting and postprandial phase. Fasting plasma concentrations of free fatty acid (FFA) and TNF-α decreased by 58 μmol/L (P = 0.02) and 0.14 pg/mL (P = 0.03), respectively. No differences were found in other fasting markers of lipid and glucose metabolism, and low-grade systemic inflammation. In addition, dietary ALA did not affect postprandial changes in glucose, insulin, triacylglycerol, FFA and plasma inflammatory markers after meal intake.

CONCLUSION

A high intake of ALA, about 3-5 times the recommended daily intake, for 12 weeks decreased fasting FFA and TNF-α plasma concentrations. No effects were found on other metabolic risk markers and vascular function during the fasting and postprandial phase in untreated high-normal and stage I hypertensive individuals.

Serum magnesium levels and risk of coronary artery disease: Mendelian randomisation study

BACKGROUND

Observational studies have shown that serum magnesium levels are inversely associated with risk of cardiovascular disease, but whether this association is causal is unknown. We conducted a Mendelian randomisation study to investigate whether serum magnesium levels may be causally associated with coronary artery disease (CAD).

METHODS

This Mendelian randomisation analysis is based on summary-level data from the CARDIoGRAMplusC4D consortium's 1000 Genomes-based genome-wide association meta-analysis of 48 studies with a total of 60,801 CAD cases and 123,504 non-cases. Six single-nucleotide polymorphisms associated with serum magnesium levels at genome-wide significance were used as instrumental variables.

RESULTS

A genetic predisposition to higher serum magnesium levels was inversely associated with CAD. In conventional Mendelian randomisation analysis, the odds ratio of CAD was 0.88 (95% confidence interval [CI] 0.78 to 0.99; P = 0.03) per 0.1-mmol/L (about 1 standard deviation) increase in genetically predicted serum magnesium levels. Results were consistent in sensitivity analyses using the weighted median and heterogeneity-penalised model averaging methods, with odds ratios of 0.84 (95% CI 0.72 to 0.98; P = 0.03) and 0.83 (95% CI 0.71 to 0.96; P = 0.02), respectively.

CONCLUSIONS

This study based on genetics provides evidence that serum magnesium levels are inversely associated with risk of CAD. Randomised controlled trials elucidating whether magnesium supplementation lowers the risk of CAD, preferably in a setting at higher risk of hypomagnesaemia, are warranted.

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.

Magnesium as a Calcification Inhibitor

Vascular calcification (VC) is associated with elevated cardiovascular mortality rates in patients with CKD. Recent clinical studies of patients with advanced CKD have observed an association between low serum magnesium (Mg) levels on one hand and elevated VC and cardiovascular mortality on the other. These findings have stimulated interest in understanding Mg's impact on CKD in general and the associated VC in particular. In vitro and preclinical in vivo data indicate that Mg has the potential to protect vascular smooth muscle cells against calcification via several different molecular mechanisms. Accordingly, data from pilot interventional studies in the clinic suggest that oral Mg supplementation reduces VC in patients with CKD. The present review provides an overview of our current understanding of the impact of Mg on the development of VC in patients with CKD.

Main Considerations of Cardiogenic Shock and Its Predictors: Systematic Review

The mortality rate of post-infarction cardiogenic shock (CS) was 80.0-90.0%. Recent studies show a significant reduction of hospital mortality to approximately 50.0%. CS is defined as systemic tissue hypoperfusion resulting from systolic and/or diastolic heart dysfunction, the main cause of which is acute myocardial infarction (AMI). The main predictors are biological markers such as troponin, CKMB and lactate. A systematic literature review and meta-analysis is performed in order to present and correlate the main literary findings on CS and its evolution with possible changes in biomarkers such as troponin, lactate and CKMB. After criteria of literary search with the use of the mesh terms: cardiogenic shock; acute myocardial infarction; biomarkers; troponin; CKMB; lactate; clinical trials and use of the bouleanos "and" between the mesh terms and "or" among the historical findings. In the main databases such as Pubmed, Medline, Bireme, EBSCO, Scielo, etc., a total of 96 papers that were submitted to the eligibility analysis were collated and, after that, 41 studies were selected, following the rules of systematic review - PRISMA (Transparent reporting of systematic reviews and meta-analyzes-http://www.prisma-statement.org/). Some risk factors for its development in AMI are advanced age, female gender, anterior wall infarction, diabetes mellitus, systemic arterial hypertension, previous history of infarction and angina. The CS associated with AMI depends on its extent and its complications, being the main ones: mitral regurgitation, rupture of the interventricular septum and rupture of the free wall of the left ventricule. The diagnosis is based on the clinical manifestations, such as mental confusion, oliguria, hypotension, tachycardia, fine pulse, sweating, and cold extremities; in hemodynamic aspects: systolic blood pressure was < 90.0 mm Hg or 30 mm Hg below baseline, pulmonary capillary pressure was > 18.0 mm Hg and cardiac index was < 2.2 L/min/m². Laboratory and imaging exams should be requested to evaluate the possible etiology of CS, its systemic repercussions and comorbidities. The treatment aims at the rapid reestablishment of the blood flow in the affected artery, to improve the patient's prognosis. The biomarkers dosage in the daily clinical practice of the different cardiological centers can facilitate the diagnosis and the conduction of the dubious cases and the best evaluation of the degree of myocardial suffering after CS.

Magnesium deficiency and increased inflammation: current perspectives

Animal studies have shown that magnesium deficiency induces an inflammatory response that results in leukocyte and macrophage activation, release of inflammatory cytokines and acute-phase proteins, and excessive production of free radicals. Animal and in vitro studies indicate that the primary mechanism through which magnesium deficiency has this effect is through increasing cellular Ca²⁺, which is the signal that results in the priming of cells to give the inflammatory response. Primary pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-1; the messenger cytokine IL-6; cytokine responders E-selectin, intracellular adhesion molecule-1 and vascular cell adhesion molecule-1; and acute-phase reactants C-reactive protein and fibrinogen have been determined to associate magnesium deficiency with chronic low-grade inflammation (inflammatory stress). When magnesium dietary intake, supplementation, and/or serum concentration suggest/s the presence of magnesium deficiency, it often is associated with low-grade inflammation and/or with pathological conditions for which inflammatory stress is considered a risk factor. When magnesium intake, supplementation, and/or serum concentration suggest/s an adequate status, magnesium generally has not been found to significantly affect markers of chronic low-grade inflammation or chronic disease. The consistency of these findings can be modified by other nutritional and metabolic factors that affect inflammatory and oxidative stress. In spite of this, findings to date provide convincing evidence that magnesium deficiency is a significant contributor to chronic low-grade inflammation that is a risk factor for a variety of pathological conditions such as cardiovascular disease, hypertension, and diabetes. Because magnesium deficiency commonly occurs in countries where foods rich in magnesium are not consumed in recommended amounts, magnesium should be considered an element of significant nutritional concern for health and well-being in these countries.