Oral magnesium supplementation improves insulin sensitivity and metabolic control in type 2 diabetic subjects: a randomized double-blind controlled trial

Fatty Acids Consumption: The Role Metabolic Aspects Involved in Obesity and Its Associated Disorders

Obesity and its associated disorders, such as insulin resistance, dyslipidemia, metabolic inflammation, dysbiosis, and non-alcoholic hepatic steatosis, are involved in several molecular and inflammatory mechanisms that alter the metabolism. Food habit changes, such as the quality of fatty acids in the diet, are proposed to treat and prevent these disorders. Some studies demonstrated that saturated fatty acids (SFA) are considered detrimental for treating these disorders. A high fat diet rich in palmitic acid, a SFA, is associated with lower insulin sensitivity and it may also increase atherosclerosis parameters. On the other hand, a high intake of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids may promote positive effects, especially on triglyceride levels and increased high-density lipoprotein (HDL) levels. Moreover, polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) are effective at limiting the hepatic steatosis process through a series of biochemical events, such as reducing the markers of non-alcoholic hepatic steatosis, increasing the gene expression of lipid metabolism, decreasing lipogenic activity, and releasing adiponectin. This current review shows that the consumption of unsaturated fatty acids, MUFA, and PUFA, and especially EPA and DHA, which can be applied as food supplements, may promote effects on glucose and lipid metabolism, as well as on metabolic inflammation, gut microbiota, and hepatic metabolism.

Effect of magnesium supplementation on type 2 diabetes associated cardiovascular risk factors: a systematic review and meta-analysis

BACKGROUND

Cardiovascular disorders remain the leading cause of death in type 2 diabetic patients. In the present study, a systematic review and a meta-analysis of randomised controlled trials (RCTs) were conducted aiming to evaluate the effect of magnesium supplementation on type 2 diabetes (T2D) associated cardiovascular risk factors in both diabetic and nondiabetic individuals.

METHODS

PubMed, Scopus, Cochrane, Web of Science and Google Scholar databases were searched from inception to 30 June 2016 aiming to identify RCTs evaluating the effect of magnesium supplementation on T2D associated cardiovascular risk factors. The data were analysed using a random effect model with inverse variance methodology. Sensitivity analysis, risk of bias analysis, subgroup analysis, meta-regression and publication bias analysis were also conducted for the included studies using standard methods.

RESULTS

Following magnesium supplementation, a significant improvement was observed in fasting plasma glucose (FPG) [weighted mean difference (WMD) = -4.641 mg dL-1 , 95% confidence interval (CI) = -7.602, -1.680, P = 0.002], high-density lipoprotein (HDL) (WMD = 3.197 mg dL-1 , 95% CI = 1.455, 4.938, P < 0.001), low-density lipoprotein (LDL) (WMD = -10.668 mg dL-1 , 95% CI = -19.108, -2.228, P = 0.013), plasma triglycerides (TG) (WMD = -15.323 mg dL-1 , 95% CI = -28.821, -1.826, P = 0.026) and systolic blood pressure (SBP) (WMD = -3.056 mmHg, 95% CI = -5.509, -0.603, P = 0.015). During subgroup analysis, a more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

CONCLUSIONS

Magnesium supplementation can produce a favourable effect on FPG, HDL, LDL, TG and SBP. Therefore, magnesium supplementation may decrease the risk T2D associated cardiovascular diseases, although future large RCTs are needed for making robust guidelines for clinical practice.

The effect of magnesium supplementation on blood pressure in individuals with insulin resistance, prediabetes, or noncommunicable chronic diseases: a meta-analysis of randomized controlled trials

Background: To our knowledge, the effect of magnesium supplementation on blood pressure (BP) in individuals with preclinical or noncommunicable diseases has not been previously investigated in a meta-analysis, and the findings from randomized controlled trials (RCTs) have been inconsistent.Objective: We sought to determine the pooled effect of magnesium supplementation on BP in participants with preclinical or noncommunicable diseases.Design: We identified RCTs that were published in English before May 2017 that examined the effect of magnesium supplementation on BP in individuals with preclinical or noncommunicable diseases through PubMed, ScienceDirect, Cochrane, clinicaltrials.gov, SpringerLink, and Google Scholar databases as well as the reference lists from identified relevant articles. Random- and fixed-effects models were used to estimate the pooled standardized mean differences (SMDs) with 95% CIs in changes in BP from baseline to the end of the trial in both systolic blood pressure (SBP) and diastolic blood pressure (DBP) between the magnesium-supplementation group and the control group.Results: Eleven RCTs that included 543 participants with follow-up periods that ranged from 1 to 6 mo (mean: 3.6 mo) were included in this meta-analysis. The dose of elemental magnesium that was used in the trials ranged from 365 to 450 mg/d. All studies reported BP at baseline and the end of the trial. The weighted overall effects indicated that the magnesium-supplementation group had a significantly greater reduction in both SBP (SMD: -0.20; 95% CI: -0.37, -0.03) and DBP (SMD: -0.27; 95% CI: -0.52, -0.03) than did the control group. Magnesium supplementation resulted in a mean reduction of 4.18 mm Hg in SBP and 2.27 mm Hg in DBP.Conclusion: The pooled results suggest that magnesium supplementation significantly lowers BP in individuals with insulin resistance, prediabetes, or other noncommunicable chronic diseases.

Fiber-rich diet with brown rice improves endothelial function in type 2 diabetes mellitus: A randomized controlled trial

Background & Aims

A fiber-rich diet has a cardioprotective effect, but the mechanism for this remains unclear. We hypothesized that a fiber-rich diet with brown rice improves endothelial function in patients with type 2 diabetes mellitus.

Methods

Twenty-eight patients with type 2 diabetes mellitus at a single general hospital in Japan were randomly assigned to a brown rice (n = 14) or white rice (n = 14) diet and were followed for 8 weeks. The primary outcome was changes in endothelial function determined from flow debt repayment by reactive hyperemia using strain-gauge plethysmography in the fasting state. Secondary outcomes were changes in HbA_1c, postprandial glucose excursions, and markers of oxidative stress and inflammation. The area under the curve for glucose after ingesting 250 kcal of assigned rice was compared between baseline (T0) and at the end of the intervention (T1) to estimate glucose excursions in each group.

Results

Improvement in endothelial function, assessed by fasting flow debt repayment (20.4% vs. −5.8%, p = 0.004), was significantly greater in the brown rice diet group than the white rice diet group, although the between-group difference in change of fiber intake was small (5.6 g/day vs. −1.2 g/day, p<0.0001). Changes in total, HDL-, and LDL-cholesterol, and urine 8-isoprostane levels did not differ between the two groups. The high-sensitivity C-reactive protein level tended to improve in the brown rice diet group compared with the white rice diet group (0.01 μg/L vs. −0.04 μg/L, p = 0.063). The area under the curve for glucose was subtly but consistently lower in the brown rice diet group (T0: 21.4 mmol/L*h vs. 24.0 mmol/L*h, p = 0.043, T1: 20.4 mmol/L*h vs. 23.3 mmol/L*h, p = 0.046) without changes in HbA_1c.

Conclusions

Intervention with a fiber-rich diet with brown rice effectively improved endothelial function, without changes in HbA1c levels, possibly through reducing glucose excursions.

Habitual coffee consumption and genetic predisposition to obesity: gene-diet interaction analyses in three US prospective studies

BACKGROUND

Whether habitual coffee consumption interacts with the genetic predisposition to obesity in relation to body mass index (BMI) and obesity is unknown.

METHODS

We analyzed the interactions between genetic predisposition and habitual coffee consumption in relation to BMI and obesity risk in 5116 men from the Health Professionals Follow-up Study (HPFS), in 9841 women from the Nurses' Health Study (NHS), and in 5648 women from the Women's Health Initiative (WHI). The genetic risk score was calculated based on 77 BMI-associated loci. Coffee consumption was examined prospectively in relation to BMI.

RESULTS

The genetic association with BMI was attenuated among participants with higher consumption of coffee than among those with lower consumption in the HPFS (P _interaction  = 0.023) and NHS (P _interaction  = 0.039); similar results were replicated in the WHI (P _interaction  = 0.044). In the combined data of all cohorts, differences in BMI per increment of 10-risk allele were 1.38 (standard error (SE), 0.28), 1.02 (SE, 0.10), and 0.95 (SE, 0.12) kg/m² for coffee consumption of < 1, 1-3 and > 3 cup(s)/day, respectively (P _interaction  < 0.001). Such interaction was partly due to slightly higher BMI with higher coffee consumption among participants at lower genetic risk and slightly lower BMI with higher coffee consumption among those at higher genetic risk. Each increment of 10-risk allele was associated with 78% (95% confidence interval (CI), 59-99%), 48% (95% CI, 36-62%), and 43% (95% CI, 28-59%) increased risk for obesity across these subgroups of coffee consumption (P _interaction  = 0.008). From another perspective, differences in BMI per increment of 1 cup/day coffee consumption were 0.02 (SE, 0.09), -0.02 (SE, 0.04), and -0.14 (SE, 0.04) kg/m² across tertiles of the genetic risk score.

CONCLUSIONS

Higher coffee consumption might attenuate the genetic associations with BMI and obesity risk, and individuals with greater genetic predisposition to obesity appeared to have lower BMI associated with higher coffee consumption.

Serum magnesium and the risk of prediabetes: a population-based cohort study

AIMS/HYPOTHESIS

Previous studies have found an association between serum magnesium and incident diabetes; however, this association may be due to reverse causation, whereby diabetes may induce urinary magnesium loss. In contrast, in prediabetes (defined as impaired fasting glucose), serum glucose levels are below the threshold for urinary magnesium wasting and, hence, unlikely to influence serum magnesium levels. Thus, to study the directionality of the association between serum magnesium levels and diabetes, we investigated its association with prediabetes. We also investigated whether magnesium-regulating genes influence diabetes risk through serum magnesium levels. Additionally, we quantified the effect of insulin resistance in the association between serum magnesium levels and diabetes risk.

METHODS

Within the population-based Rotterdam Study, we used Cox models, adjusted for age, sex, lifestyle factors, comorbidities, kidney function, serum levels of electrolytes and diuretic use, to study the association between serum magnesium and prediabetes/diabetes. In addition, we performed two mediation analyses: (1) to study if common genetic variation in eight magnesium-regulating genes influence diabetes risk through serum magnesium levels; and (2) to quantify the proportion of the effect of serum magnesium levels on diabetes that is mediated through insulin resistance (quantified by HOMA-IR).

RESULTS

A total of 8555 participants (mean age, 64.7 years; median follow-up, 5.7 years) with normal glucose levels (mean ± SD: 5.46 ± 0.58 mmol/l) at baseline were included. A 0.1 mmol/l decrease in serum magnesium level was associated with an increase in diabetes risk (HR 1.18 [95% CI 1.04, 1.33]), confirming findings from previous studies. Of interest, a similar association was found between serum magnesium levels and prediabetes risk (HR 1.12 [95% CI 1.01, 1.25]). Genetic variation in CLDN19, CNNM2, FXYD2, SLC41A2, and TRPM6 significantly influenced diabetes risk (p < 0.05), and for CNNM2, FXYD2, SLC41A2 and TRPM6 this risk was completely mediated by serum magnesium levels. We found that 29.1% of the effect of serum magnesium levels on diabetes was mediated through insulin resistance, whereas for prediabetes 13.4% was mediated through insulin resistance.

CONCLUSIONS/INTERPRETATION

Low serum magnesium levels are associated with an increased risk of prediabetes and this increased risk is similar to that of diabetes. Furthermore, common variants in magnesium-regulating genes modify diabetes risk through serum magnesium levels. Both findings support a potential causal role of magnesium in the development of diabetes, where the hypothesised pathway is partly mediated through insulin resistance.

Nutrition for diabetic retinopathy: plummeting the inevitable threat of diabetic vision loss

Diabetic retinopathy (DR) is among the leading causes of preventable blindness. Hyperglycemia, hypertension, hyperlipidemia and anemia majorly predispose its pathogenesis. The current treatment modalities of DR include laser photocoagulation therapy, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents and vitreo-retinal surgery which are costly, highly invasive, unproven for prolonged use and opted in advanced stages of DR. By then retina already encounters a vast damage. Nutrients by their natural physiological, biochemical and molecular action can preserve retinal structure and functions by interfering with the various pathological steps prompting DR incidence, thereby altering the risk of developing this ocular morbidity. Nutrients can also play a central role in DR patients resistant towards the conventional medical treatments. However due to the byzantine interplay existing between nutrients and DR, the worth of nutrition in curbing this vision-threatening ocular morbidity remains silent. This review highlights how nutrients can halt DR development. A nutritional therapy, if adopted in the initial stages, can provide superior-efficacy over the current treatment modalities and can be a complementary, inexpensive, readily available, anodyne option to the clinically unmet requirement for preventing DR. Assessment of nutritional status is presently considered relevant in various clinical conditions except DR. Body Mass Index (BMI) conferred inconclusive results in DR subjects. Subjective Global Assessment (SGA) of nutritional status has recently furnished relevant association with DR status. By integrating nutritional strategies, the risk of developing DR can be reduced substantially. This review summarizes the subsisting knowledge on nutrition, potentially beneficial for preventing DR and sustaining good vision among diabetic subjects.

Oral magnesium supplementation improves glycemic control and lipid profile in children with type 1 diabetes and hypomagnesaemia

Dietary supplementation with magnesium (Mg) in addition to classical therapies for diabetes may help in prevention or delaying of diabetic complications.We aimed to evaluate the status of serum Mg in children with type 1 diabetes and assessing its relationship to glycemic control and lipid profile. Then evaluating the effect of oral Mg supplementation on glycemic control and lipid parameters.We included 71 children at Pediatric Endocrinology Outpatient Clinic, Zagazig University, Egypt with type 1 diabetes and assessed HBA1c, lipid profile, and serum Mg at the start of study. Patients with serum Mg level < 1.7 mg/dL were given 300 mg Mg oxide for 3 months. After that we reevaluated HBA1c, lipid profile, and serum Mg in all patients.The study included 71 patients with type 1 diabetes (32 males and 39 females); their mean age was 9.68 ± 3.99 years. The mean serum Mg level was 1.83 ± .27 mg/dL. Hypomagnesemia was detected in 28.2% study patients. Serum Mg was found to be positively correlated with high density lipoprotein, mean corpuscular volume and platelet count (P < 0.001), and negatively correlated with age, HbA1c, triglycerides, total cholesterol, low density lipoprotein, and duration of diabetes (P < 0.001). There was significant reduction in HBA1c in group given Mg supplementation. HBA1c was initially 10.11% ± 0.87%. After 3 months of oral Mg supplementation it is reduced to 7.88% ± 0.42% (P < 0.001). There was statistically significant difference in lipid parameters in hypomagnesemic diabetic patients before and after Mg supplementation with significant reduction in serum triglycerides, LDL, and total cholesterol following Mg supplementation with P < 0.001. Although HDL shows a significant increase after Mg supplementation in hypomagnesemic diabetic children with P < 0.001.Correction of hypomagnesemia in type 1 diabetic children with oral Mg supplements is associated with optimization of glycemic control and reduction of atherogenic lipid fraction as well as increase in protective lipid fraction.

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

PURPOSE

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.

METHODS

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.

RESULTS

Magnesium treatment was not found to significantly affect plasma concentrations of any of the lipid indices including total cholesterol (WMD 0.03 mmol/L, 95% CI -0.11, 0.16, p = 0.671), LDL-C (WMD -0.01 mmol/L, 95% CI -0.13, 0.11, p = 0.903), HDL-C (WMD 0.03 mmol/L, 95% CI -0.003, 0.06, p = 0.076), and triglycerides concentrations (WMD -0.10 mmol/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.

CONCLUSIONS

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.

Magnesium Deficiency is Associated with Periodontal Disease

In the multifactorial pathogenesis of periodontitis, there are still unknown factors influencing the outcome of the disease. An association between magnesium and periodontitis has been suggested by preliminary studies. However, relevant clinical data are lacking. We investigated the association between magnesium status and periodontal health in a population-based analysis. We conducted a cross-sectional epidemiological investigation involving 4290 subjects aged 20–80 yrs. We recorded periodontal risk factors and determined concentrations of serum magnesium and calcium, relating them to periodontal parameters. In a matched-pair study, 60 subjects using oral magnesium-containing drugs and 120 without were compared. In subjects aged 40 yrs and older, increased serum Mg/Ca was significantly associated with reduced probing depth (p < 0.001), less attachment loss (p = 0.006), and a higher number of remaining teeth (p = 0.005). Subjects taking Mg drugs showed less attachment loss (p < 0.01) and more remaining teeth than did their matched counterparts. These results suggest that nutritional magnesium supplementation may improve periodontal health.

Perspective: The Case for an Evidence-Based Reference Interval for Serum Magnesium: The Time Has Come

The 2015 Dietary Guidelines Advisory Committee indicated that magnesium was a shortfall nutrient that was underconsumed relative to the Estimated Average Requirement (EAR) for many Americans. Approximately 50% of Americans consume less than the EAR for magnesium, and some age groups consume substantially less. A growing body of literature from animal, epidemiologic, and clinical studies has demonstrated a varied pathologic role for magnesium deficiency that includes electrolyte, neurologic, musculoskeletal, and inflammatory disorders; osteoporosis; hypertension; cardiovascular diseases; metabolic syndrome; and diabetes. Studies have also demonstrated that magnesium deficiency is associated with several chronic diseases and that a reduced risk of these diseases is observed with higher magnesium intake or supplementation. Subclinical magnesium deficiency can exist despite the presentation of a normal status as defined within the current serum magnesium reference interval of 0.75-0.95 mmol/L. This reference interval was derived from data from NHANES I (1974), which was based on the distribution of serum magnesium in a normal population rather than clinical outcomes. What is needed is an evidenced-based serum magnesium reference interval that reflects optimal health and the current food environment and population. We present herein data from an array of scientific studies to support the perspective that subclinical deficiencies in magnesium exist, that they contribute to several chronic diseases, and that adopting a revised serum magnesium reference interval would improve clinical care and public health.

Obesity and hypomagnesemia

BACKGROUND

Whether low serum magnesium is an epiphenomenon related with obesity or, whether obesity per se is cause of hypomagnesemia, remains to be clarified.

OBJECTIVE

To examine the relationship between body weight status and hypomagnesemia in apparently healthy subjects.

METHODS

A total of 681 healthy individuals aged 30 to 65years were enrolled in A cross-sectional study. Extreme exercise, chronic diarrhea, alcohol intake, use of diuretics, smoking, oral magnesium supplementation, diabetes, malnutrition, hypertension, liver disease, thyroid disorders, and renal damage were exclusion criteria. Based in the Body Mass Index (BMI), body weight status was defined as follows: normal weight (BMI <25kg/m²); overweight (BMI ≥25<30 BMIkg/m²); and obesity (BMI ≥30kg/m²). Hypomagnesemia was defined by serum magnesium concentration ≤0.74mmol/L. A multiple logistic regression analysis was used to compute the odds ratio (OR) between body weight status (independent variables) and hypomagnesemia (dependent variable).

RESULTS

The multivariate logistic regression analysis showed that dietary magnesium intake (OR 2.11; 95%CI 1.4-5.7) but no obesity (OR 1.53; 95%CI 0.9-2.5), overweight (OR 1.40; 95%CI 0.8-2.4), and normal weight (OR 0.78; 95%CI 0.6-2.09) were associated with hypomagnesemia. A subsequent logistic regression analysis adjusted by body mass index, waist circumference, total body fat, systolic and diastolic blood pressure, and triglycerides levels showed that hyperglycemia (2.19; 95%CI 1.1-7.0) and dietary magnesium intake (2.21; 95%CI 1.1-8.9) remained associated with hypomagnesemia.

CONCLUSIONS

Our results show that body weight status is not associated with hypomagnesemia and that, irrespective of obesity, hyperglycemia is cause of hypomagnesemia in non-diabetic individuals.

Effect of magnesium supplementation on glucose metabolism in people with or at risk of diabetes: a systematic review and meta-analysis of double-blind randomized controlled trials

Although higher dietary intakes of magnesium (Mg) seem to correspond to lower diabetes incidence, research concerning Mg supplementation in people with or at risk of diabetes is limited. Thus, we 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 placebo. A literature search in PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials and Clinicaltrials.gov without language restriction, was undertaken. Eligible studies were randomized controlled trials (RCTs) investigating the effect of oral Mg supplementation vs placebo in patients with diabetes or at high risk of diabetes. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used for summarizing outcomes with at least two studies; other outcomes were summarized descriptively. Eighteen RCTs (12 in people with diabetes and 6 in people at high risk of diabetes) were included. Compared with placebo (n=334), Mg treatment (n=336) reduced fasting plasma glucose (studies=9; SMD=-0.40; 95% CI: -0.80 to -0.00; I²=77%) in people with diabetes. In conditions in people at high risk of diabetes (Mg: 226; placebo=227 participants), Mg supplementation significantly improved plasma glucose levels after a 2 h oral glucose tolerance test (three studies; SMD=-0.35; 95% CI: -0.62 to -0.07; I²=0%) and demonstrated trend level reductions in HOMA-IR (homeostatic model assessment-insulin resistance; five studies; SMD=-0.57; 95% CI: -1.17 to 0.03; I²=88%). Mg supplementation appears to have a beneficial role and improves glucose parameters in people with diabetes and also improves insulin-sensitivity parameters in those at high risk of diabetes.

Effects of Magnesium Supplementation on Blood Pressure

The antihypertensive effect of magnesium (Mg) supplementation remains controversial. We aimed to quantify the effect of oral Mg supplementation on blood pressure (BP) by synthesizing available evidence from randomized, double-blind, placebo-controlled trials. We searched trials of Mg supplementation on normotensive and hypertensive adults published up to February 1, 2016 from MEDLINE and EMBASE databases; 34 trials involving 2028 participants were eligible for this meta-analysis. Weighted mean differences of changes in BP and serum Mg were calculated by random-effects meta-analysis. Mg supplementation at a median dose of 368 mg/d for a median duration of 3 months significantly reduced systolic BP by 2.00 mm Hg (95% confidence interval, 0.43–3.58) and diastolic BP by 1.78 mm Hg (95% confidence interval, 0.73–2.82); these reductions were accompanied by 0.05 mmol/L (95% confidence interval, 0.03, 0.07) elevation of serum Mg compared with placebo. Using a restricted cubic spline curve, we found that Mg supplementation with a dose of 300 mg/d or duration of 1 month is sufficient to elevate serum Mg and reduce BP; and serum Mg was negatively associated with diastolic BP but not systolic BP (all P <0.05). In the stratified analyses, a greater reduction in BP tended to be found in trials with high quality or low dropout rate (all P values for interaction <0.05). However, residual heterogeneity may still exist after considering these possible factors. Our findings indicate a causal effect of Mg supplementation on lowering BPs in adults. Further well-designed trials are warranted to validate the BP-lowering efficacy of optimal Mg treatment.

In vitro studies on the pleotropic antidiabetic effects of zinc oxide nanoparticles

Aim: Our earlier study demonstrated antidiabetic activity of zinc oxide nanoparticles (ZON) in diabetic rats. The present study was performed to elucidate its mechanism of antidiabetic action. Methods: Protein tyrosine phosphatase 1B, protein kinase B and hormone sensitive lipase phosphorylation; glucose transporter 4 translocation and glucose uptake; glucose 6 phosphatase, phosphoenol pyruvate carboxykinase and glucokinase expression; and pancreatic beta cell proliferation were evaluated after ZON treatment to cells. Result: ZON treatment resulted in PKB activation, protein tyrosine phosphatase 1B inactivation, increased glucose transporter 4 translocation and enhanced glucose uptake, decreased glucose 6 phosphatase and phosphoenol pyruvate carboxykinase expression, hormone sensitive lipase inactivation and pancreatic beta cell proliferation. Conclusion: To the best of our knowledge, we report for the first time, pleiotropic antidiabetic effects of ZON viz. improved insulin signaling, enhanced glucose uptake, decreased hepatic glucose output, decreased lipolysis and enhanced pancreatic beta cell mass.

Dietary supplements and disease prevention - a global overview

Dietary supplements are widely used and offer the potential to improve health if appropriately targeted to those in need. Inadequate nutrition and micronutrient deficiencies are prevalent conditions that adversely affect global health. Although improvements in diet quality are essential to address these issues, dietary supplements and/or food fortification could help meet requirements for individuals at risk of deficiencies. For example, supplementation with vitamin A and iron in developing countries, where women of reproductive age, infants and children often have deficiencies; with folic acid among women of reproductive age and during pregnancy; with vitamin D among infants and children; and with calcium and vitamin D to ensure bone health among adults aged ≥65 years. Intense debate surrounds the benefits of individual high-dose micronutrient supplementation among well-nourished individuals because the alleged beneficial effects on chronic diseases are not consistently supported. Daily low-dose multivitamin supplementation has been linked to reductions in the incidence of cancer and cataracts, especially among men. Baseline nutrition is an important consideration in supplementation that is likely to modify its effects. Here, we provide a detailed summary of dietary supplements and health outcomes in both developing and developed countries to help guide decisions about dietary supplement recommendations.

A systematic review and meta-analysis of randomized controlled trials on the effects of magnesium supplementation on insulin sensitivity and glucose control

A systematic review and meta-analysis was conducted to evaluate the effect of oral magnesium supplementation on insulin sensitivity and glucose control in both diabetic and non-diabetic individuals. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched (from inception to November 25, 2015) to identify RCTs evaluating the effect of magnesium on insulin sensitivity and glucose control. A random-effects model and 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. The impact of magnesium supplementation on plasma concentrations of glucose, glycated hemoglobin (HbA1c), insulin, and HOMA-IR index was assessed in 22, 14, 12 and 10 treatment arms, respectively. A significant effect of magnesium supplementation was observed on HOMA-IR index (WMD: -0.67, 95% CI: -1.20, -0.14, p=0.013) but not on plasma glucose (WMD: -0.20mmol/L, 95% CI: -0.45, 0.05, p=0.119), HbA1c (WMD: 0.018mmol/L, 95% CI: -0.10, 0.13, p=0.756), and insulin (WMD: -2.22mmol/L, 95% CI: -9.62, 5.17, p=0.556). A subgroup analysis comparing magnesium supplementation durations of <4 months versus ≥4 months, exhibited a significant difference for fasting glucose concentrations (p<0.001) and HOMA-IR (p=0.001) in favor of the latter subgroup. Magnesium supplementation for ≥4 months significantly improves the HOMA-IR index and fasting glucose, in both diabetic and non-diabetic subjects. The present findings suggest that magnesium may be a beneficial supplement in glucose metabolic disorders.

Whole food approach for type 2 diabetes prevention

Diet is intimately associated with the risk of type 2 diabetes (T2D). Recently, attention has focused on the contributions of individual nutrients, food groups and eating patterns to the outcome of T2D. High consumption of coffee, whole grains, fruits and vegetables, and nuts are each independently associated with the reduced risk of T2D in high risk, glucose intolerant individuals. Experimental and clinical trials have given insight to the diverse mechanisms that may be responsible for the observed protective effects of certain foods on T2D, including nutrients, phytochemicals and dietary fiber, weight control, enhanced satiety and improvement in glucose tolerance and insulin sensitivity in diabetic patients. Elevated consumption of refined grains and sugar-sweetened beverages has shown to significantly elevate the risk of incident T2D. An overall healthy diet primarily comprising whole plant-based foods, together with regular physical activity and weight manage, could significantly reduce the risk of T2D. The present review consolidates current research and delineates major food groups shown to significantly influence risk of T2D. Documenting and quantifying the effects of diet on the outcome of T2D are of great scientific and public health importance as there is urgent need to implement dietary strategies to prevent and manage the outcome of T2D.

Altered serum levels of FGF-23 and magnesium are independent risk factors for an increased albumin-to-creatinine ratio in type 2 diabetics with chronic kidney disease

AIMS

To investigate the role of FGF-23 and magnesium in relation to the albumin-to-creatinine ratio in type 2 diabetics with chronic kidney disease (CKD) stages 2-4.

METHODS

In a cross-sectional study we included all eligible type 2 diabetic patients with CKD stages 2-4, followed in our outpatient Diabetic Kidney clinic. We used descriptive statistics, the Student'st-test, ANOVA and the chi-square tests. Our population was divided according to the UACR (G1 30-300 mg/g and G2≥300 mg/g), and compared these groups regarding several biological and laboratorial parameters. We employed a multiple regression model to identify risk factors of increased UACR.

RESULTS

The patients in G2 displayed a lower eGFR (p=0.0001) and, had lower levels of magnesium (p=0.004) as well as higher levels of FGF-23 (p=0.043) compared to patients in G1. FGF-23 (β=0.562, P=0.0001) and the magnesium (β=- 8.916, p=0.0001) were associated with increased UACR.

CONCLUSIONS

A dysregulation of mineral metabolism, reflected by altered levels of magnesium and FGF-23, correlates with an increased UACR in type 2 diabetic patients with CKD stages 2-4.

Hypomagnesemia in Type 2 Diabetes: A Vicious Circle?

Over the past decades, hypomagnesemia (serum Mg(2+) <0.7 mmol/L) has been strongly associated with type 2 diabetes mellitus (T2DM). Patients with hypomagnesemia show a more rapid disease progression and have an increased risk for diabetes complications. Clinical studies demonstrate that T2DM patients with hypomagnesemia have reduced pancreatic β-cell activity and are more insulin resistant. Moreover, dietary Mg(2+) supplementation for patients with T2DM improves glucose metabolism and insulin sensitivity. Intracellular Mg(2+) regulates glucokinase, KATP channels, and L-type Ca(2+) channels in pancreatic β-cells, preceding insulin secretion. Moreover, insulin receptor autophosphorylation is dependent on intracellular Mg(2+) concentrations, making Mg(2+) a direct factor in the development of insulin resistance. Conversely, insulin is an important regulator of Mg(2+) homeostasis. In the kidney, insulin activates the renal Mg(2+) channel transient receptor potential melastatin type 6 that determines the final urinary Mg(2+) excretion. Consequently, patients with T2DM and hypomagnesemia enter a vicious circle in which hypomagnesemia causes insulin resistance and insulin resistance reduces serum Mg(2+) concentrations. This Perspective provides a systematic overview of the molecular mechanisms underlying the effects of Mg(2+) on insulin secretion and insulin signaling. In addition to providing a review of current knowledge, we provide novel directions for future research and identify previously neglected contributors to hypomagnesemia in T2DM.

Association of hypermagnesemia and blood pressure in the critically ill

BACKGROUND

Although magnesium is important in the biology of blood pressure regulation, little clinical data exist on the association of hypermagnesemia and blood pressure.

METHOD

We examined the association of hypermagnesemia and SBP in a cross-sectional study of 10 521 ICU patients from a single tertiary care medical center, 6% of whom had a serum magnesium above 2.6 mg/dl at time of admission.

RESULTS

In a multivariable analysis, hypermagnesemia was associated with SBP 6.2 mmHg lower [95% confidence interval (CI) -8.2, -4.2, P < 0.001] than in patients with admission values of serum magnesium 2.6 mg/dl or less. Each mg/dl increase in serum magnesium was associated with a decrease in SBP of 4.3 mmHg (95% CI -5.5, -3.1, P < 0.001). In addition, hypermagnesemic patients had a 2.48-fold greater likelihood (95% CI 2.06, 3.00, P < 0.001) of receiving intravenous vasopressors during the first 24 h of ICU care, independent of admission SBP.

CONCLUSION

Our findings add support to the biologic importance of magnesium regulation in blood pressure control.

Hypomagnesemia and the Risk of New-Onset Diabetes Mellitus after Kidney Transplantation

Several studies suggest a link between post-transplant hypomagnesemia and new-onset diabetes after transplantation (NODAT), but this relationship remains controversial. We conducted a retrospective cohort study of 948 nondiabetic kidney transplant recipients from January 1, 2000, to December 31, 2011, to examine the association between serum magnesium level and NODAT. Multivariable Cox proportional hazards models were fitted to evaluate the risk of NODAT as a function of baseline (at 1 month), time-varying (every 3 months), and rolling-average (i.e., mean for 3 months moving at 3-month intervals) serum magnesium levels while adjusting for potential confounders. A total of 182 NODAT events were observed over 2951.2 person-years of follow-up. Multivariable models showed an inverse relationship between baseline serum magnesium level and NODAT (hazard ratio [HR], 1.24 per 0.1 mmol/L decrease; 95% confidence interval [95% CI], 1.05 to 1.46; P=0.01). The association with the risk of NODAT persisted in conventional time-varying (HR, 1.32; 95% CI, 1.14 to 1.52; P<0.001) and rolling-average models (HR, 1.34; 95% CI, 1.13 to 1.57; P=0.001). Hypomagnesemia (serum magnesium <0.74 mmol/L) also significantly associated with increased risk of NODAT in baseline (HR, 1.58; 95% CI, 1.07 to 2.34; P=0.02), time-varying (HR, 1.78; 95% CI, 1.29 to 2.45; P<0.001), and rolling-average models (HR, 1.83; 95% CI, 1.30 to 2.57; P=0.001). Our results suggest that lower post-transplant serum magnesium level is an independent risk factor for NODAT in kidney transplant recipients. Interventions targeting serum magnesium to reduce the risk of NODAT should be evaluated.

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.

Magnesium and type 2 diabetes

Type 2 diabetes is frequently associated with both extracellular and intracellular magnesium (Mg) deficits. A chronic latent Mg deficit or an overt clinical hypomagnesemia is common in patients with type 2 diabetes, especially in those with poorly controlled glycemic profiles. Insulin and glucose are important regulators of Mg metabolism. Intracellular Mg plays a key role in regulating insulin action, insulin-mediated-glucose-uptake and vascular tone. Reduced intracellular Mg concentrations result in a defective tyrosine-kinase activity, postreceptorial impairment in insulin action and worsening of insulin resistance in diabetic patients. A low Mg intake and an increased Mg urinary loss appear the most important mechanisms that may favor Mg depletion in patients with type 2 diabetes. Low dietary Mg intake has been related to the development of type 2 diabetes and metabolic syndrome. Benefits of Mg supplementation on metabolic profiles in diabetic patients have been found in most, but not all clinical studies and larger prospective studies are needed to support the potential role of dietary Mg supplementation as a possible public health strategy in diabetes risk. The aim of this review is to revise current evidence on the mechanisms of Mg deficiency in diabetes and on the possible role of Mg supplementation in the prevention and management of the disease.

Dysmagnesemia in Hospitalized Patients: Prevalence and Prognostic Importance

OBJECTIVE

To examine the prevalence of serum magnesium (Mg) alterations and outcomes in hospitalized patients.

PATIENTS AND METHODS

All admissions to Mayo Clinic in Rochester, Minnesota, from January 1, 2009, through December 31, 2013 (288,120 patients), were screened. Admission Mg from each unique patient and relevant clinical data were extracted from the institutional electronic database.

RESULTS

After excluding patients aged less than 18 years, those without Mg measurement, and readmission episodes, a total of 65,974 patients were studied. Magnesium levels of 2.1 mg/dL or higher were found in 20,777 patients (31.5%), and levels less than 1.7 mg/dL were noted in 13,320 (20.2%). Hypomagnesemia was common in patients with hematologic/oncological disorders, and hypermagnesemia was common in those with cardiovascular disease. The lowest hospital mortality, assessed by restricted cubic spline and percentage death, occurred in patients with Mg levels between 1.7 and 1.89 mg/dL. An Mg level of less than 1.7 mg/dL was independently associated with an increased risk of hospital mortality after adjusting for all variables except the admission diagnosis; risk for longer hospital stay and being discharged to a care facility were increased in the fully adjusted model. An elevated Mg level of 2.3 mg/dL or higher was a predictor for all adverse outcomes. The magnitude of Mg elevations in patients with levels of 2.3 mg/dL or higher (N=7908) was associated with worse hospital mortality in a dose-response manner. In patients with cardiovascular diseases, Mg levels of 1.5 to 1.69 mg/dL and 2.3 mg/dL or higher both independently predicted poor outcomes including hospital mortality.

CONCLUSION

Dysmagnesemia in hospitalized patients is common, with hypermagnesemia being most prevalent. Compared with hypomagnesemia, hypermagnesemia is a stronger predictor for poor outcomes. Magnesium supplementation for patients without Mg deficiency should be avoided in the absence of randomized controlled trials documenting a benefit.

Does magnesium matter in patients of Medical Intensive Care Unit: A study in rural Central India

INTRODUCTION

Hypomagnesemia has been common, but mostly underdiagnosed electrolyte abnormality. Studies regarding this is lacking in India especially in rural setting. Here, we have correlated serum magnesium (Mg) level with outcome in patients of medicine Intensive Care Unit (ICU) with respect to length of ICU stay, need for mechanical ventilatory support and its duration and ultimate outcome (discharge/death).

MATERIALS AND METHODS

This is a prospective observational study carried out over a period of 1-year enrolling 601 patients of Medical ICU (MICU). The Chi-square test is applied to correlate hypomagnesemia with the outcome.

RESULT AND OBSERVATION

About 25% patients had admission hypomagnesemia. When compared with the normal Mg group, there was significant association of hypomagnesemia with outcome in terms of duration of MICU stay 5.46 (5.75) versus 3.93 (3.88), need for mechanical ventilation (56.86% vs. 24.33%), discharge/cured from ICU (61.43% vs. 85.26%), and death (38.56% vs. 14.73%). However, no significant difference was found in the duration of ventilation between the two groups.

CONCLUSION

Hypomagnesemia is associated with a higher mortality rate in critically ill patients. The need for ventilatory support, but not its duration is significantly higher in hypomagnesemic patients. Hypomagnesemia is commonly associated with sepsis and diabetes mellitus. The duration of MICU stay is significantly higher in patients with low serum Mg.

Magnesium supplementation affects metabolic status and pregnancy outcomes in gestational diabetes: a randomized, double-blind, placebo-controlled trial

BACKGROUND

To our knowledge, prior research has not examined the effects of magnesium supplementation on metabolic status and pregnancy outcomes in maternal-child dyads affected by gestational diabetes (GDM).

OBJECTIVE

This study was designed to assess the effects of magnesium supplementation on metabolic status and pregnancy outcomes in magnesium-deficient pregnant women with GDM.

DESIGN

A randomized, double-blind, placebo-controlled clinical trial was performed in 70 women with GDM. Patients were randomly assigned to receive either 250 mg magnesium oxide (n = 35) or a placebo (n = 35) for 6 wk. Fasting blood samples were taken at baseline and after a 6-wk intervention.

RESULTS

The change in serum magnesium concentration was greater in women consuming magnesium than in the placebo group (+0.06 ± 0.3 vs. -0.1 ± 0.3 mg/dL, P = 0.02). However, after controlling for baseline magnesium concentrations, the changes in serum magnesium concentrations were not significantly different between the groups. Changes in fasting plasma glucose (-9.7 ± 10.1 vs. +1.8 ± 8.1 mg/dL, P < 0.001), serum insulin concentration (-2.1 ± 6.5 vs. +5.7 ± 10.7 μIU/mL, P = 0.001), homeostasis model of assessment-estimated insulin resistance (-0.5 ± 1.3 vs. +1.4 ± 2.3, P < 0.001), homeostasis model of assessment-estimated β-cell function (-4.0 ± 28.7 vs. +22.0 ± 43.8, P = 0.006), and the quantitative insulin sensitivity check index (+0.004 ± 0.021 vs. -0.012 ± 0.015, P = 0.005) in supplemented women were significantly different from those in women in the placebo group. Changes in serum triglycerides (+2.1 ± 63.0 vs. +38.9 ± 37.5 mg/dL, P = 0.005), high sensitivity C-reactive protein (-432.8 ± 2521.0 vs. +783.2 ± 2470.1 ng/mL, P = 0.03), and plasma malondialdehyde concentrations (-0.5 ± 1.6 vs. +0.3 ± 1.2 μmol/L, P = 0.01) were significantly different between the supplemented women and placebo group. Magnesium supplementation resulted in a lower incidence of newborn hyperbilirubinemia (8.8% vs. 29.4%, P = 0.03) and newborn hospitalization (5.9% vs. 26.5%, P = 0.02).

CONCLUSION

Magnesium supplementation among women with GDM had beneficial effects on metabolic status and pregnancy outcomes. This trial was registered at www.irct.ir as IRCT201503055623N39.

Effect of multivitamin versus multivitamin-mineral supplementation on metabolic profiles and biomarkers of oxidative stress in pregnant women: a double-blind randomized clinical trial

OBJECTIVE

This study was designed to determine the favorable effects of received multivitamin versus multivitamin-mineral supplements on metabolic profiles and biomarkers of oxidative stress among Iranian pregnant women.

METHODS

This double-blind randomized-controlled clinical trial was conducted among 70 pregnant women, primigravida, aged 18-35 years old between 16 and 37 weeks gestation. Subjects were randomly assigned to receive either the multivitamin (n = 35) or multivitamin-mineral supplements (n = 35) for 20 weeks. Fasting blood samples were taken at baseline and after a 20-week intervention to measure lipid profiles and biomarkers of oxidative stress.

RESULTS

After 20 weeks of intervention, multivitamin-mineral supplementation resulted in a significant difference on serum triglycerides levels (changes from baseline in multivitamin-mineral group: +6.1 versus in multivitamin group: +45.9 mg/dl, p = 0.04) compared with the multivitamin group. In addition, increased concentrations of serum HDL-cholesterol (changes from baseline in multivitamin-mineral group: +0.1 versus in multivitamin group: -7.4 mg/dl, p = 0.02) and total glutathione (GSH) levels (changes from baseline in multivitamin-mineral group: +151.09 versus in multivitamin group: -116.21 µmol/l, p = 0.003) were also seen in the multivitamin-mineral group compared with the multivitamin group.

CONCLUSION

Supplementation of multivitamin-mineral compared to multivitamin supplementation for 20 weeks during pregnancy had beneficial effects on triglycerides, HDL-cholesterol and GSH levels.

Magnesium in disease

Although the following text will focus on magnesium in disease, its role in healthy subjects during physical exercise when used as a supplement to enhance performance is also noteworthy. Low serum magnesium levels are associated with metabolic syndrome, Type 2 diabetes mellitus (T2DM) and hypertension; consequently, some individuals benefit from magnesium supplementation: increasing magnesium consumption appears to prevent high blood pressure, and higher serum magnesium levels are associated with a lower risk of developing a metabolic syndrome. There are, however, conflicting study results regarding magnesium administration with myocardial infarction with and without reperfusion therapy. There was a long controversy as to whether or not magnesium should be given as a first-line medication. As the most recent trials have not shown any difference in outcome, intravenous magnesium cannot be recommended in patients with myocardial infarction today. However, magnesium has its indication in patients with torsade de pointes and has been given successfully to patients with digoxin-induced arrhythmia or life-threatening ventricular arrhythmias. Magnesium sulphate as an intravenous infusion also has an important established therapeutic role in pregnant women with pre-eclampsia as it decreases the risk of eclamptic seizures by half compared with placebo.

Magnesium modifies the association between serum phosphate and the risk of progression to end-stage kidney disease in patients with non-diabetic chronic kidney disease

It is known that magnesium antagonizes phosphate-induced apoptosis of vascular smooth muscle cells and prevents vascular calcification. Here we tested whether magnesium can also counteract other pathological conditions where phosphate toxicity is involved, such as progression of chronic kidney disease (CKD). We explored how the link between the risk of CKD progression and hyperphosphatemia is modified by magnesium status. A post hoc analysis was run in 311 non-diabetic CKD patients who were divided into four groups according to the median values of serum magnesium and phosphate. During a median follow-up of 44 months, 135 patients developed end-stage kidney disease (ESKD). After adjustment for relevant clinical factors, patients in the lower magnesium-higher phosphate group were at a 2.07-fold (95% CI: 1.23-3.48) risk for incident ESKD and had a significantly faster decline in estimated glomerular filtration rate compared with those in the higher magnesium-higher phosphate group. There were no significant differences in the risk of these renal outcomes among the higher magnesium-higher phosphate group and both lower phosphate groups. Incubation of tubular epithelial cells in high phosphate and low magnesium medium in vitro increased apoptosis and the expression levels of profibrotic and proinflammatory cytokine; these changes were significantly suppressed by increasing magnesium concentration. Thus, magnesium may act protectively against phosphate-induced kidney injury.

Magnesium in CKD: more than a calcification inhibitor?

Magnesium fulfils important roles in multiple physiological processes. Accordingly, a tight regulation of magnesium homeostasis is essential. Dysregulated magnesium serum levels, in particular hypomagnesaemia, are common in patients with chronic kidney disease (CKD) and have been associated with poor clinical outcomes. In cell culture studies as well as in clinical situations magnesium levels were associated with vascular calcification, cardiovascular disease and altered bone-mineral metabolism. Magnesium has also been linked to diseases such as metabolic syndrome, diabetes, hypertension, fatigue and depression, all of which are common in CKD. The present review summarizes and discusses the latest clinical data on the impact of magnesium and possible effects of higher levels on the health status of patients with CKD, including an outlook on the use of magnesium-based phosphate-binding agents in this context.

Management of glycemia in diabetic patients with stage IV and V chronic kidney disease

Diabetic kidney disease is a leading cause of end-stage kidney disease worldwide. Data suggest that prevention of progression to end-stage may lie in excellent blood glucose control; however, as kidney disease progresses, the risk of hypoglycemia increases, due to unpredictable insulin kinetics and altered pharmacokinetics of hypoglycemic agents. In addition, whole classes of hypoglycemic agents become contraindicated and regimens must be adjusted for declining kidney function. There is no consensus regarding the best therapy for the patient with advanced chronic kidney disease. In the best of circumstances, the care of these patients will involve intensive monitoring, with the input of a team of health care providers creating a coordinated care plan, including dietary advice and a drug regimen tailored to the specific issues faced by the individual patient. An open dialogue is necessary at all times, as patients may become frustrated and attempt self-treatment using over the counter alternatives.

Magnesium in man: implications for health and disease

Magnesium (Mg(2+)) is an essential ion to the human body, playing an instrumental role in supporting and sustaining health and life. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Although Mg(2+) availability has been proven to be disturbed during several clinical situations, serum Mg(2+) values are not generally determined in patients. This review aims to provide an overview of the function of Mg(2+) in human health and disease. In short, Mg(2+) plays an important physiological role particularly in the brain, heart, and skeletal muscles. Moreover, Mg(2+) supplementation has been shown to be beneficial in treatment of, among others, preeclampsia, migraine, depression, coronary artery disease, and asthma. Over the last decade, several hereditary forms of hypomagnesemia have been deciphered, including mutations in transient receptor potential melastatin type 6 (TRPM6), claudin 16, and cyclin M2 (CNNM2). Recently, mutations in Mg(2+) transporter 1 (MagT1) were linked to T-cell deficiency underlining the important role of Mg(2+) in cell viability. Moreover, hypomagnesemia can be the consequence of the use of certain types of drugs, such as diuretics, epidermal growth factor receptor inhibitors, calcineurin inhibitors, and proton pump inhibitors. This review provides an extensive and comprehensive overview of Mg(2+) research over the last few decades, focusing on the regulation of Mg(2+) homeostasis in the intestine, kidney, and bone and disturbances which may result in hypomagnesemia.

SERUM magnesium levels as an indicator of status of Diabetes Mellitus type 2

CONTEXT

Magnesium deficiency is commonly associated with endocrine and metabolic disorders, especially with Diabetes Mellitus type 2 though the mechanism of hypomagnesemia in Diabetes Mellitus is not completely known. There is a close association between metabolic control of Diabetes Mellitus and impaired magnesium balance.

AIMS

To estimate the serum levels of magnesium in patients of with Diabetes Mellitus type 2 and to find a correlation if any, with the duration and control (by estimating HbA1c) of Diabetes Mellitus type 2.

MATERIALS AND METHODS

Fifty patients of Diabetes Mellitus type 2 were included in the study. Blood samples were analyzed for fasting and post prandial glucose, HbA1c and magnesium. The patients were grouped into three categories based upon their HbA1c levels into those with good control, need intervention and poor control. The three groups were compared with reference to their mean levels of blood glucose and magnesium. Association of serum magnesium levels with HbA1c, Fasting and postprandial blood glucose and duration of Diabetes Mellitus was also done.

RESULTS

Serum magnesium levels were found to decline with rise in HbA1c levels and with duration of Diabetes Mellitus type 2.

CONCLUSION

Hypomagnesemia is linked to poor control of Diabetes Mellitus type 2 and depletion of serum magnesium occurs exponentially with duration of disease.

Effects of magnesium supplements on blood pressure, endothelial function and metabolic parameters in healthy young men with a family history of metabolic syndrome

BACKGROUND AND AIMS

Magnesium plays an important role in the modulation of vascular tone and endothelial function and can regulate glucose and lipid metabolism. Patients with hypertension, metabolic syndrome (MetS) and diabetes mellitus (T2DM) have low body magnesium content; indeed, magnesium supplementation has been shown to have a positive effect on blood pressure (BP) and gluco-metabolic parameters. The aim of our study was to evaluate the effect of magnesium supplements on hemodynamic and metabolic parameters in healthy men with a positive family history of MetS or T2DM.

METHODS AND RESULTS

In a randomized, double-blind, placebo-controlled 8-week crossover trial with a 4 week wash-out period, oral supplements of 8.1 mmol of magnesium-pidolate or placebo were administered twice a day to 14 healthy normomagnesemic participants, aged 23-33 years. The primary endpoint was office BP, measured with a semiautomatic oscillometric device. Secondary endpoints included characteristics of the MetS, namely endothelial function, arterial stiffness and inflammation. Plasma and urinary magnesium were measured in all participants while free intracellular magnesium was measured only in a subsample. There was no significant difference in either systolic and diastolic BP in participants post-magnesium supplementation and post-placebo treatment when compared to baseline BP measurements. Further, the metabolic, inflammatory and hemodynamic parameters did not vary significantly during the study.

CONCLUSIONS

Our study showed no beneficial effect of magnesium supplements on BP, vascular function and glycolipid profile in young men with a family history of MetS/T2DM (trial registration at clinicaltrial.gov ID: NCT01181830; 12th of Aug 2010).

The use of plants in the traditional management of diabetes in Nigeria: pharmacological and toxicological considerations

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.

MATERIALS AND METHODS

Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. 'Diabetes' and 'Nigeria' were used as keywords for the primary searches; and then 'Plant name - accepted or synonyms', 'Constituents', 'Drug interaction' and/or 'Toxicity' for the secondary searches.

RESULTS

The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.

CONCLUSION

This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb-drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided.

Magnesium replacement does not improve insulin resistance in patients with metabolic syndrome: a 12-week randomized double-blind study

Background

To evaluate the effect of magnesium (Mg) replacement on insulin resistance and cardiovascular risk factors in women with metabolic syndrome (MS) without diabetes.

Methods

This 12-week clinical randomized double-blind study compared the effects of 400 mg/day of Mg with those of a placebo (n = 72) on fasting glucose, insulin, HOMA-IR, lipid profile and CRP. Mg was measured in serum (SMg) and in mononuclear cells (MMg).

Results

Hypomagnesemia (SMg < 1.7 mg/dL) was seen in 23.2% of patients and intracellular depletion in 36.1% of patients. The MMg means were lower in patients with obesity (0.94 ± 0.54 μg/mg vs. 1.19 ± 0.6 μg/mg, P = 0.04), and insulin resistance (0.84 ± 0.33 μg/mg vs. 1.14 ± 0.69 µg/mg, P < 0.05). Mg replacement did not alter SMg (1.82 ± 0.14 mg/dL vs. 1.81 ± 0.16 mg/dL, P = 0.877) and tended to increment MMg (0.90 ± 0.40 μg/mg vs. 1.21 ± 0.73 μg/mg, P = 0.089). HOMA-IR did not alter in interventions nor in placebo group (3.2 ± 2.0 to 2.8 ± 1.9, P = 0.368; 3.6 ± 1.9 to 3.2 ± 1.8, respectively), neither did other metabolic parameters.

Conclusion

Serum and intracellular Mg depletion is common in patients with MS; however, Mg replacement in recommended dosage did not increase significantly Mg levels, neither reduced insulin resistance or metabolic control.

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

BACKGROUND

Magnesium deficiency is associated with poor physical performance, but no trials are available on how magnesium supplementation affects elderly people's physical performance.

OBJECTIVE

The aim of our study was to investigate whether 12 wk of oral magnesium supplementation can improve physical performance in healthy elderly women.

DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Anti-diabetic effect of a preparation of vitamins, minerals and trace elements in diabetic rats: a gender difference

BACKGROUND

Although multivitamin products are widely used as dietary supplements to maintain health or as special medical food in certain diseases, the effects of these products were not investigated in diabetes mellitus, a major cardiovascular risk factor. Therefore, here we investigated if a preparation of different minerals, vitamins, and trace elements (MVT) for human use affects the severity of experimental diabetes.

METHODS

Two days old neonatal Wistar rats from both genders were injected with 100 mg/kg of streptozotocin or its vehicle to induce diabetes. At week 4, rats were fed with an MVT preparation or vehicle for 8 weeks. Well established diagnostic parameters of diabetes, i.e. fasting blood glucose and oral glucose tolerance test were performed at week 4, 8 and 12. Moreover, serum insulin and blood HbA1c were measured at week 12.

RESULTS

An impaired glucose tolerance has been found in streptozotocin-treated rats in both genders at week 4. In males, fasting blood glucose and HbA1c were significantly increased and glucose tolerance and serum insulin was decreased at week 12 in the vehicle-treated diabetic group as compared to the vehicle-treated non-diabetic group. All of the diagnostic parameters of diabetes were significantly improved by MVT treatment in male rats. In females, streptozotocin treatment resulted in a less severe prediabetic-like phenotype as only glucose tolerance and HbA1c were altered by the end of the study in the vehicle-treated diabetic group as compared to the vehicle-treated non-diabetic group. MVT treatment failed to improve the diagnostic parameters of diabetes in female streptozotocin-treated rats.

CONCLUSION

This is the first demonstration that MVT significantly attenuates the progression of diabetes in male rats with chronic experimental diabetes. Moreover, we have confirmed that females are less sensitive to STZ-induced diabetes and MVT preparation did not show protection against prediabetic state. This may suggest a gender difference in the pathogenesis of diabetes.

The BRAzil MAGnesium (BRAMAG) trial: a randomized clinical trial of oral magnesium supplementation in pregnancy for the prevention of preterm birth and perinatal and maternal morbidity

BACKGROUND

Preterm birth is the leading cause of infant mortality globally, including Brazil. We will evaluate whether oral magnesium citrate reduces the risk of placental dysfunction and its negative consequences for both the fetus and mother, which, in turn, should reduce the need for indicated preterm delivery.

METHODS/DESIGN

We will complete a multicenter, randomized double-blind clinical trial comparing oral magnesium citrate 150 mg twice daily (n = 2000 women) to matched placebo (n = 1000 women), starting at 121/7 to 206/7 weeks gestation and continued until delivery. We will include women at higher risk for placental dysfunction, based on clinical factors from a prior pregnancy (e.g., prior preterm delivery, stillbirth or preeclampsia) or the current pregnancy (e.g., chronic hypertension, pre-pregnancy diabetes mellitus, maternal age > 35 years or pre-pregnancy maternal body mass index > 30 kg/m2). The primary perinatal outcome is a composite of preterm birth < 37 weeks gestation, stillbirth > 20 weeks gestation, neonatal death < 28 days, or SGA birthweight < 3rd percentile. The primary composite maternal outcome is preeclampsia arising < 37 weeks gestation, severe non-proteinuric hypertension arising < 37 weeks gestation, placental abruption, maternal stroke during pregnancy or ≤ 7 days after delivery, or maternal death during pregnancy or ≤ 7 days after delivery.

DISCUSSION

The results of this randomized clinical trial may be especially relevant in low and middle income countries that have high rates of prematurity and limited resources for acute newborn and maternal care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02032186, registered December 19, 2013.

Micronutrient status in type 2 diabetes: a review

Type 2 diabetes is characterized by significant losses of important micronutrients due to metabolic basis of the disease and its complications. Evidence of changes in trace mineral and vitamin metabolism as a consequence of type 2 diabetes is reviewed in this chapter. This review is not a meta-analysis but an overview of the micronutrient status, metabolic needs, and potential micronutrient requirements in type 2 diabetics. This chapter will not concentrate on vitamin D and type 2 diabetes as this is a topic that has been extensively reviewed before. The less well-known micronutrients notably zinc, magnesium, chromium, copper, manganese, iron, selenium, vanadium, B-group vitamins, and certain antioxidants are assessed. While some evidence is available to demonstrate the positive influence of micronutrient supplementation on glycemic control, much remains to be investigated. Additional research is necessary to characterize better biomarkers of micronutrient status and requirements in type 2 diabetics. The optimal level of micronutrient supplementation to achieve glucose homeostasis in type 2 diabetics remains a challenge.