Effect Of Oral Magnesium Supplementation Research Articles

Oral magnesium supplementation does not affect insulin sensitivity in people with insulin-treated type 2 diabetes and a low serum magnesium: a randomised controlled trial

Aims/hypothesisHypomagnesaemia has been associated with insulin resistance and an increased risk of type 2 diabetes. Whether magnesium supplementation improves insulin sensitivity in people with type 2 diabetes and a low serum magnesium level is unknown.MethodsUsing a randomised, double-blind (both participants and investigators were blinded to the participants’ treatment sequences), placebo-controlled, crossover study design, we compared the effect of oral magnesium supplementation (15 mmol/day) for 6 weeks with that of matched placebo in individuals with insulin-treated type 2 diabetes (age ≥18 years, BMI 18–40 kg/m2, HbA1c <100 mmol/mol [11.3%], serum magnesium ≤0.79 mmol/l). Participants were recruited from the outpatient clinic and through advertisements. Randomisation to a treatment sequence order was done using a randomisation list. We used block randomisation and the two possible treatment sequences were evenly distributed among the trial population. The primary outcome was the mean glucose infusion rate during the final 30 min of a hyperinsulinaemic–euglycaemic clamp (i.e. M value). Secondary outcomes included variables of glucose control, insulin need, BP, lipid profile and hypomagnesaemia-related symptoms during follow-up.ResultsWe recruited 14 participants (50% women, 100% White, mean ± SD age 67±6 years, BMI 31±5 kg/m2, HbA1c 58±9 mmol/mol [7.4±0.9%]) with insulin-treated type 2 diabetes. Magnesium supplementation increased both mean ± SEM serum magnesium level (0.75±0.02 vs 0.70±0.02 mmol/l, p=0.016) and urinary magnesium excretion (magnesium/creatinine ratio, 0.23±0.02 vs 0.15±0.02, p=0.005), as compared with placebo. The M value of the glucose clamp did not differ between the magnesium and placebo study arms (4.6±0.5 vs 4.4±0.6 mg kg−1 min−1, p=0.108). During the 6 weeks of treatment, continuous glucose monitoring outcomes, HbA1c, insulin dose, lipid profile and BP also did not differ, except for a lower HDL-cholesterol concentration after magnesium compared with placebo (1.14±0.08 vs 1.20±0.09 mmol/l, p=0.026). Symptoms potentially related to hypomagnesaemia were similar for both treatment arms.Conclusions/interpretationDespite an albeit modest increase in serum magnesium concentration, oral magnesium supplementation does not improve insulin sensitivity in people with insulin-treated type 2 diabetes and low magnesium levels.Trial registrationEudraCT number 2021-001243-27.FundingThis study was supported by a grant from the Dutch Diabetes Research Foundation (2017–81–014).Graphical

Clinical trial on the effects of oral magnesium supplementation in stable-phase COPD patients

Background and aimsCOPD is a common chronic condition in older age that impacts on daily activities and quality of life. Previous studies suggest that magnesium deficit in COPD patients affects bronco-obstruction, inflammation, and physical performance. We investigated whether oral magnesium supplementation in stable-phase COPD patients improves lung function, physical performance, and quality of life.MethodsWe conducted a double-blind randomized-controlled clinical study with 49 participants divided into two groups: one given 300 mg/day of magnesium citrate (n = 25) and the other one sachet/day of a placebo (n = 24). The following parameters were assessed at baseline and after 3 and 6 months: lung function (spirometry), physical performance (handgrip strength, lower limb strength, six-minute walk test), inflammation (e.g., C-reactive protein, CRP), disease-related symptoms, and quality of life (St George’s Respiratory Questionnaire, EuroQoL-5D, the Modified British Medical Research Council Questionnaire).ResultsLinear mixed models revealed significantly lower CRP values in the intervention group than in the placebo group at the 6 month follow-up (β = − 3.2, 95% CI − 6.0, − 0.4, p = 0.03). Moreover, the maximum work for flexion tended to increase in both groups between the 3 and the 6 month assessments, especially in the placebo group. No significant differences within and between groups over the study period were observed for the other parameters tested.ConclusionsAlthough the established minimum sample size was not reached, our results suggests that oral magnesium supplementation may have a potential anti-inflammatory role. On the other hand, it does not seem to substantially influence lung function, physical performance, and quality of life in COPD patients.Trial registrationThe study is registered in clinicaltrial.gov (Trial Registration: NCT02680769, 13 June 2016, retrospectively registered).

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 0.75mg/L; P = 0.44), IL-6 (WMD, - 0.03; 95% CI, - 0.40 to 0.33pg/mL; P = 0.86), and TNF-α (WMD, 0.12; 95% CI, - 0.08 to 0.31pg/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.

The effect of oral magnesium supplementation on acute non-specific low back pain: Prospective randomized clinical trial.

We aimed to investigate the effect of oral magnesium supplementation for acute low back pain. This is a three-arm, prospective randomized open label clinical trial, which included two hundred and forty patients. We based our sample size calculation assumptions on a recently published clinical trial, thus we enrolled 80 patients for each group. NSAID alone group included (400 mg etodolac twice a day), NSAID + mg group included NSAID - magnesium combination treatment (400 mg etodolac twice a day with 365 mg oral magnesium supplementation) and NSAID + paracetamol group included NSAID - paracetamol combination treatment (400 mg etodolac twice a day with 500 mg paracetamol twice a day). Follow-up visits after initiation of relevant treatment were performed at 4th and 10th days and outcome measures included pain (Visual analogue scale - VAS), mobility of lumbar spine and functional outcome (RMDQ). Thirty-one patients were considered lost to follow-up or excluded due to use of other medications and final analysis was performed with 209 participants in three groups (71 patients in NSAID alone group, 68 patients in NSAID + mg group and 70 patients in NSAID + paracetamol group). NSAID + mg showed a significantly higher improvement in RMDQ and VAS scores at acute stage (at 4th day visit) compared to two other study groups However, there was no significant difference between three groups in terms of mean improvement of RMDQ, VAS scores and lumbar mobility between initial visit and 10-day. Results of this study suggest that addition of magnesium to acute low-back pain treatment does not significantly improve final clinical outcomes. Level I, prospective randomized controlled study.

Effect of oral magnesium supplementation on serum magnesium levels in children recovering from severe acute malnutrition

The Journal is the primary organ of Continuing Paediatric Medical Education in Sri Lanka. The journal also has a website. Free full text access is available for all readers.The Sri Lanka Journal of Child Health is now indexed in SciVerse Scopus (Source Record ID 19900193609), Index Medicus for South-East Asia Region (IMSEAR), CABI (Centre for Agriculture and Bioscience International Global Health Database), DOAJ and is available in Google, as well as Google Scholar.The policies of the journal are modelled on the Committee on Publication Ethics (COPE) Guidelines on Principles of Transparency and Best Practice in Scholarly Publishing. Sri Lanka Journal of Child Health is recognised by the International Committee of Medical Journal Editors (ICMJE) as a publication following the ICMJE Recommendations.

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.

Metformin-Mg2+ adjunct therapy synergistically modulates insulin and PDX-1 gene signatures in STZ-NAD induced diabetic model

Diabetes mellitus (DM) is a multi-factorial debilitating disorder of metabolism, usually due to a combination of hereditary and environmental causes, resulting in abnormally high blood sugar levels (hyperglycemia) as a result of defects in either insulin secretion or insulin action in the body. DM is usually accompanied by hypomagnesemia. This study was aimed at investigating the effect of oral magnesium supplementation on pancreatic gene expression of insulin and PDX-1 in type-2 streptozotocin-nicotinamide induced Sprague dawley diabetic rats. A total of 24Sprague dawleyrats (Four groups of six rats each), were used for this study; Group 1: Normal rats (CONTROL) given distilled water for 4weeks; Group 2: Metformin + Magnesium treated rats (DMM) orally given 100mg/kg and 1000mg/kg body weight respectively for 4weeks; Group 3: Metformin treated diabetic rats (DM), orally given 100mg/kg body weight for 4weeks; Group 4: Diabetic untreated control rats (DU) given distilled water for 4weeks. Measured data were analyzed statistically. The result revealed that there was significant (p&lt;0.05) increase in the feed and water intake of the treated rats but the metformin-magnesium supplement treated group showed more increase when compared with only metformin treated group. PDX-1 and insulin gene expression levels were significantly (p&lt;0.05) higher in the control when compared with all the diabetic groups. However, PDX-1 and insulin mRNA levels were significantly (p&lt;0.05) higher in DMM, when compared with DM. DMM showed improvements when compared with DM which suggests magnesium supplementation as an adjunct therapy with metformin may help inthe regeneration of the beta cells of the pancreas.

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

The effects of magnesium (Mg) supplementation on vascular function have been evaluated in some randomized controlled trials (RCT) but their results are conflicting. Asystematic review and meta-analysis were conducted to summarize the effects of oral Mg supplementation on vascular function in RCT. 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. 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 6months, in unhealthy subjects, in individuals older than 50years, or in those with body mass index (BMI) ≥ 25kg/m2. The reduced number of RCT and the heterogeneity among them were the main limitations. This meta-analysis suggest that oral Mg supplementation may improve endothelial function when conducted at least for 6months and in unhealthy, overweight or older individuals. Registration number: PROSPERO CRD42019111462.

The Effects of Oral Magnesium Supplementation on Glycemic Response among Type 2 Diabetes Patients.

Background: Magnesium (Mg) supplementation may help control glycemic response among type 2 diabetes (T2D) patients. Objective: This study means to determine whether Mg supplementation improves glycemic control indicators in patients with T2D. Methods: After one week of the dietary stabilization phase, 42 T2D patients were stratified according to sex, age, fasting blood sugar (FBS) and Mg levels and then randomly allocated into two groups. The intervention group was on 250 mg/day of elemental Mg for three months while the control group did not receive any type of supplements throughout the intervention period. Results: The daily administration of 250 mg of elemental Mg indicated a significant improvement in HbA1C (8.32 to 7.96%, p < 0.001), insulin levels (IL) (15.56 to 12.18 μIU/mL, p < 0.001), C-peptide (2.28 to 1.90 ng/mL, p = 0.001), HOMA.IR (6.16 to 4.44, p < 0.001) and HOMA.β% (59.99 to 52.37, p = 0.036) of the intervention group when compared with the control group after three months of intervention. Conclusion: The results of this study revealed that oral Mg supplementation reduces insulin resistance and improves the glycemic control indicators among T2D patients. Trial registration: current controlled trials PHRC/HC/32/15. Registered 5 October 2015.

1804P - Effect of oral magnesium supplementation on the kinetics of magnesium wasting induced by EGFR targeted antibody therapy for colorectal carcinoma (MAGNET trial)

1804P - Effect of oral magnesium supplementation on the kinetics of magnesium wasting induced by EGFR targeted antibody therapy for colorectal carcinoma (MAGNET trial)

Effect of Magnesium Supplementation on Plasma C-reactive Protein Concentrations: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Results of previous clinical trials evaluating the effect of magnesium supplementation on inflammatory markers are controversial. A systematic review and meta-analysis of randomized controlled trials (RCTs) were performed to evaluating the effect of oral magnesium supplementation on plasma C-reactive protein (CRP) concentrations. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched (from inception to August 09, 2016) to identify RCTs, evaluating the effect of magnesium on CRP levels. A random-effects model and a generic inverse variance method were used to compensate for the heterogeneity of studies. Publication bias, sensitivity analysis, and meta-regression assessments were conducted using standard methods. Overall, the impact of magnesium supplementation on plasma concentrations of CRP was assessed in 11 studies. Magnesium treatment was not found to significantly affect plasma concentrations of CRP (WMD: -0.11 mg/L, 95% CI: -0.75, 0.52, p=0.727). When the analysis was stratified to compare subgroups of studies in populations with baseline plasma CRP values of ≤ 3 and > 3 mg/L, a significant reduction of CRP values was observed in the latter subgroup (WMD: -1.12 mg/L, 95% CI: -2.05, -0.18, p=0.019) but not in the former group (WMD: 0.61 mg/L, 95% CI: -0.10, 1.32, p=0.090). The difference between subgroups was statistically significant (p=0.004). Results of the present meta-analysis indicated that magnesium supplementation reduces CRP levels among individuals with inflammation (CRP levels > 3 mg/dL). This finding suggests that magnesium supplements may have a beneficial role as an adjuvant for the management of low-grade chronic systemic inflammation.

Effect of oral magnesium supplementation on the transcription of TRPM6, TRPM7, and SLC41A1 in individuals newly diagnosed of pre-hypertension. A randomized, double-blind, placebo-controlled trial.

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.

Effect of magnesium supplementation on lipid profile: a systematic review and meta-analysis of randomized controlled trials.

We performed a meta-analysis of randomized controlled trials (RCTs) in order to evaluate the effect of oral magnesium supplementation on lipid profile of both diabetic and non-diabetic individuals. PubMed-Medline, SCOPUS, Web of Science, and Google Scholar databases were searched (from inception to February 23, 2016) to identify RCTs evaluating the effect of magnesium on lipid concentrations. A random-effects model and generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. A weighted random-effects meta-regression was performed to evaluate the impact of potential confounders on lipid concentrations. Magnesium treatment was not found to significantly affect plasma concentrations of any of the lipid indices including total cholesterol (WMD 0.03mmol/L, 95% CI -0.11, 0.16, p=0.671), LDL-C (WMD -0.01mmol/L, 95% CI -0.13, 0.11, p=0.903), HDL-C (WMD 0.03mmol/L, 95% CI -0.003, 0.06, p=0.076), and triglycerides concentrations (WMD -0.10mmol/L, 95% CI -0.25, 0.04, p=0.149). In a subgroup analysis comparing studies with and without diabetes, no difference was observed between subgroups in terms of changes in plasma total cholesterol (p=0.924), LDL-C (p=0.161), HDL-C (p=0.822), and triglyceride (p=0.162) concentrations. Results of the present meta-analysis indicated that magnesium supplementation showed no significant effects on the lipid profile of either diabetic or non-diabetic individuals.

Oral magnesium supplementation reduces the incidence of gastrointestinal complications following cardiac surgery: a randomized clinical trial.

Gastrointestinal complications are common after coronary artery bypass graft surgery. These complications are ranged from nausea and vomiting to mesenteric ischemia and liver failure. It seems that nausea, vomiting, and constipation are related to magnesium deficiency. This study was designed to examine the effect of oral magnesium supplementation on the incidence of gastrointestinal complications in patients undergoing cardiac surgery. In a single blinded randomized clinical trial, 102 patients who were undergoing coronary artery bypass graft surgery were randomly allocated into two groups, 52 patients in the intervention and 50 patients in control group. Patients in the experimental group received 800 milligram magnesium oxide (2 tablets each of them containing 240mg elemental magnesium) daily from the admission to discharge from hospital. The incidence of post-operative nausea and vomiting, constipation, and atrial fibrillation was compared between the groups. Our results showed that postoperative hypomagnesemia is present in 41.20 and 70.80 percent of the patients in the intervention and control group patients, respectively. The overall incidence of constipation was 62%. Patients who received magnesium supplementation experienced less atrial fibrillation, nausea, vomiting, and constipation. Our data showed that oral magnesium supplementation could reduce the postoperative complications. Despite the better status in the intervention group, the hypomagnesemia was present in many of intervention group patients. It seems that supplementation with higher doses is needed.

Magnesium in metabolic syndrome: a review based on randomized, double-blind clinical trials.

A growing body of evidence shows the effect of magnesium on serum glucose, HDL-cholesterol, and triglycerides levels, as well as on blood pressure, which strongly suggests that magnesium might play an important role in metabolic syndrome (MetS), a cluster of risk factors for cardiovascular disease and type 2 diabetes. We performed a systematic review of clinical evidence derived from randomized, double-blind, controlled clinical trials, regarding the efficacy of magnesium supplementation on the components of MetS. Using the electronic databases of Medline, Embase, and the Cochrane Controlled Trials Register up to May 2016, we looked for randomized controlled trials focused on the effects of oral magnesium supplementation on insulin sensitivity, glucose, triglyceride and HDL-cholesterol levels, as well as its effects on high blood pressure, irrespective of the magnesium salt used, and with a duration of at least four weeks. Crossover studies, irrespective of blinding criteria, were not included. Results of this review show that magnesium supplementation in individuals with hypomagnesemia can be effective in the treatment of MetS.

Abstract 49: Effects of Oral Magnesium Supplementation on Blood Pressure Among Healthy or Hypertensive Adults: A Meta-analysis of Randomized Double-blinded Placebo-controlled Trials

Introduction: The role of magnesium (Mg) in blood pressure (BP) is controversial, due to inconsistent results from prior individual trials or systematic reviews and meta-analyses. Hypothesis: We aimed to quantify the effect of oral Mg supplementation on systolic and diastolic BP by synthesizing available evidence from randomized double-blinded placebo-controlled trials. We also examined whether changes in BP were related to elevation in serum Mg levels by Mg supplementation. Methods: We searched all trials of oral Mg supplementation among healthy or hypertensive adults published before February 1, 2015 from databases of MEDLINE and EMBASE. A random-effects meta-analysis was performed to estimate weighted mean differences (WMDs) and 95% confidence intervals (CIs) of BP changes. The possible heterogeneity between studies were explored by subgroup analyses. We used restricted cubic spline curves to depict time- and dose-responses of BP in relation to changes of serum Mg levels. Results: In total, 33 eligible trials involving 2,500 participants were included. Mg supplementation at a median dose of 368 mg/day elemental Mg for a median duration of 3 months led to significantly reduced supine BPs by 2.08 mmHg (95% CI: 0.49, 3.68) for systolic BP and 1.83 mmHg (95% CI: 0.77, 2.90) for diastolic BP compared with the placebo. Overall, Mg supplementation significantly increased serum Mg concentrations by 0.05 mmol/L (95% CI: 0.03, 0.07 mmol/L). Our time- and dose-response analyses showed that Mg supplementation with 200 mg/day for 1 month was sufficient to significantly raise serum Mg and lower supine BPs (all P-values &lt; 0.0001). However, higher doses (≥ 300 mg/day) and longer durations (≥ 2 months) were needed to achieve maximal effects. On average, per 0.1 mmol/L increment in serum Mg was associated with a supine DBP reduction of 2.26 mmHg (95% CI: 0.27, 4.26 mmHg), while the linear or curvilinear relationship with supine SBP was non-significant. In addition, there were non-significant changes in standing BPs (all P-values &gt; 0.05). Conclusions: Our meta-analysis showed that Mg supplementation significantly lowered supine BPs which were significantly related with elevated serum Mg levels. Our findings support an antihypertensive effect of Mg, although future large well-designed randomized controlled trials with longer follow-up, selection of participants with low Mg levels, and ambulatory BP monitoring are warranted.

The effect of acute vs chronic magnesium supplementation on exercise and recovery on resistance exercise, blood pressure and total peripheral resistance on normotensive adults.

BackgroundMagnesium supplementation has previously shown reductions in blood pressure of up to 12 mmHg. A positive relationship between magnesium supplementation and performance gains in resistance exercise has also been seen. However, no previous studies have investigated loading strategies to optimise response. The aim of this study was to assess the effect of oral magnesium supplementation on resistance exercise and vascular response after intense exercise for an acute and chronic loading strategy on a 2-day repeat protocol.MethodsThe study was a randomised, double-blind, cross-over design, placebo controlled 2 day repeat measure protocol (n = 13). Intense exercise (40 km time trial) was followed by bench press at 80% 1RM to exhaustion, with blood pressure and total peripheral resistance (TPR) recorded. 300 mg/d elemental magnesium was supplemented for either a 1 (A) or 4 (Chr) week loading strategy. Food diaries were recorded.ResultsDietary magnesium intake was above the Reference Nutrient Intake (RNI) for all groups. Bench press showed a significant increase of 17.7% (p = 0.031) for A on day 1. On day 2 A showed no decrease in performance whilst Chr showed a 32.1% decrease. On day 2 post-exercise systolic blood pressure (SBP) was significantly lower in both A (p = 0.0.47) and Chr (p = 0.016) groups. Diastolic blood pressure (DBP) showed significant decreases on day 2 solely for A (p = 0.047) with no changes in the Chr. TPR reduced for A on days 1 and 2 (p = 0.031) with Chr showing an increase on day 1 (p = 0.008) and no change on day 2.ConclusionThere was no cumulative effect of Chr supplementation compared to A. A group showed improvement for bench press concurring with previous research which was not seen in Chr. On day 2 A showed a small non-significant increase but not a decrement as expected with Chr showing a decrease. DBP showed reductions in both Chr and A loading, agreeing with previous literature. This is suggestive of a different mechanism for BP reduction than for muscular strength. TPR showed greater reductions with A than Chr, which would not be expected as both interventions had reductions in BP, which is associated with TPR.

Effect of magnesium supplementation on blood pressure and vascular reactivity in nitric oxide synthase inhibition-induced hypertension model

The aim of this study was to assess the effect of oral magnesium supplementation (Mg-supp) on blood pressure (BP) and possible mechanism in nitric oxide synthase (NOS) inhibition-induced hypertension model. Hypertension and/or Mg-supp were created by N-nitro-l-arginine methyl ester (25 mg/kg/day by drinking water) and magnesium-oxide (0.8% by diet) for 6 weeks. Systolic BP was measured weekly by tail-cuff method. The effects of hypertension and/or Mg-supp in thoracic aorta and third branch of mesenteric artery constriction and relaxation responses were evaluated. NOS-inhibition produced a gradually developing hypertension and the magnitude of the BP was significantly attenuated after five weeks of Mg-supp. The increased phenylephrine-induced contractile and decreased acetylcholine (ACh)-induced dilation responses were found in both artery segments of hypertensive groups. Mg-supp was restored ACh-relaxation response in both arterial segments and also Phe-constriction response in thoracic aorta but not in mesenteric arteries. The contributions of NO, prostaglandins and K+ channels to the dilator response of ACh were similar in the aorta of all the groups. The contribution of the NO to the ACh-mediated relaxation response of mesenteric arteries was suppressed in hypertensive rats, whereas this was corrected by Mg-supp. The flow-mediated dilation response of mesenteric arteries in hypertensive rats failed and could not be corrected by Mg-supp. Whereas, vascular eNOS protein and magnesium levels were not changed and plasma nitrite levels were reduced in hypertensive rats. The results of this study showed that Mg-supp lowered the arterial BP in NOS-inhibition induced hypertension model by restoring the agonist-induced relaxation response of the arteries.

Magnesium and disturbances in carbohydrate metabolism.

Magnesium is actively involved in a number of metabolic reactions as an important co-factor, with special emphasis on carbohydrate metabolism. After a brief overview of the regulation of intra- and extracellular magnesium, the present review first describes the regulatory role of magnesium in important metabolic pathways involved in energy metabolism and glycaemic control. Next the clinical significance of hypomagnesaemic conditions with regard to the management of glucose in prediabetic stages, such as insulin resistance/impaired glucose tolerance and in type 2 diabetes mellitus are characterized. Cross-sectional as well as longitudinal studies suggest that a reduced dietary magnesium intake serves as a risk factor for the incidence of both impaired glucose regulation and type 2 diabetes. Mechanisms that might be responsible for diabetes-associated hypomagnesaemia are discussed. Furthermore, the role of hypomagnesaemia in the development and progression of chronic diabetic complications are addressed. Finally, the available literature on the effects of magnesium supplementation on glycaemic control parameters during prediabetic conditions (preventive approach) as well as type 2 diabetes mellitus (therapeutic approach) are reviewed systematically. There is considerable evidence that chronic magnesium supplementation may delay the progression from impaired glucose regulation to type 2 diabetes; however, the effects of oral magnesium supplementation as an adjunct therapy for type 2 diabetes are quite heterogeneous with respect to the various measures of glycaemic control. The results of this review suggest a requirement for critical consideration of the pros and cons of magnesium replacement therapy, based on variables such as magnesium status, stage of disease and glycaemic control.

Effect of oral magnesium supplementation on physical performance in healthy elderly women involved in a weekly exercise program: a randomized controlled trial , ,

Magnesium deficiency is associated with poor physical performance, but no trials are available on how magnesium supplementation affects elderly people's physical performance. The aim of our study was to investigate whether 12 wk of oral magnesium supplementation can improve physical performance in healthy elderly women. In a parallel-group, randomized controlled trial, 139 healthy women (mean ± SD age: 71.5 ± 5.2 y) attending a mild fitness program were randomly allocated to a treatment group (300 mg Mg/d; n = 62) or a control group (no placebo or intervention; n = 77) by using a computer-generated randomization sequence, and researchers were blinded to their grouping. After assessment at baseline and again after 12 wk, the primary outcome was a change in the Short Physical Performance Battery (SPPB); secondary outcomes were changes in peak torque isometric and isokinetic strength of the lower limbs and handgrip strength. A total of 124 participants allocated to the treatment (n = 53) or control (n = 71) group were considered in the final analysis. At baseline, the SPPB scores did not differ between the 2 groups. After 12 wk, the treated group had a significantly better total SPPB score (Δ = 0.41 ± 0.24 points; P = 0.03), chair stand times (Δ = -1.31 ± 0.33 s; P < 0.0001), and 4-m walking speeds (Δ = 0.14 ± 0.03 m/s; P = 0.006) than did the control group. These findings were more evident in participants with a magnesium dietary intake lower than the Recommended Dietary Allowance. No significant differences emerged for the secondary outcomes investigated, and no serious adverse effects were reported. Daily magnesium oxide supplementation for 12 wk seems to improve physical performance in healthy elderly women. These findings suggest a role for magnesium supplementation in preventing or delaying the age-related decline in physical performance.