Magnesium intake decreases Type 2 diabetes risk through the improvement of insulin resistance and inflammation: the Hisayama Study

Serum magnesium and calcium were inversely associated with hemoglobin glycation index and triglyceride-glucose index in adults with coronary artery disease

Little is known about the associations of magnesium (Mg) and calcium (Ca) with hemoglobin glycation index (HGI) and triglyceride-glucose index (TyG) in adults. In this study, we examined the associations of serum Mg and Ca with HGI and TyG in adults with coronary artery disease (CAD). This hospital-based cross-sectional study included 10757 CAD patients with a mean age of 61.6 years. Serum concentrations of Mg and Ca were measured in clinical laboratory. Overall, serum Mg and Ca were inversely associated with HGI and TyG. In multivariable analyses, Mg and Ca were inversely associated with HGI (MgQ4 vs. Q3: -0.601 vs. -0.528; CaQ4 vs. Q1: -0.769 vs. -0.645). In terms of TyG, inverse associations of serum Mg and Ca with TyG were observed. The corresponding TyG values were 9.054 (vs. 9.099) for Mg and 9.068 (vs. 9.171) for Ca in the fourth quartile compared with the first quartile. Moreover, Mg, Ca or Mg/Ca ratio were also inversely associated with HbA1c and FBG. In path analysis, no mediating effects of obesity on "serum Mg (or Ca)- HGI (or TyG)" associations were observed. Generally, our study identified the inverse associations of the serum Mg and Ca levels with HGI and TyG in adults with CAD. Large sample longitudinal study, and particularly randomized controlled trials, are warranted to validate our findings and overcome the limitations of cross-sectional studies.

Study on the Dose-Response Relationship between Magnesium and Type 2 Diabetes of Childbearing Women in the China Adult Chronic Disease and Nutrition Surveillance 2015

Background: Magnesium (Mg) is an essential element and participates in many metabolic pathways. Many studies have found a certain negative correlation between magnesium and blood glucose parameters, but the dose-response relationship between them is still a relatively narrow research field. We aim to explore the dose-response relationship between plasma and dietary Mg and type 2 diabetes (T2DM) among childbearing women in a nationally representative sample. And we will also initially explore the threshold of dietary and plasma magnesium in the prevention of T2DM and their consistency. Methods: A total of 2912 18-44 year-old childbearing women were recruited from the China Adult Chronic Disease and Nutrition Surveillance (2015). Multivariate logistic regression was used to explore the dose-response relationship between plasma and dietary Mg and glucose parameters. The threshold effect between Mg and T2DM was explored by a restricted cubic spline regression. Results: It was found that when plasma Mg was increased by 0.041 mmol/L, the risk of T2DM, impaired fasting glucose (IFG), and HbA1c-hyperglycemia was reduced by 18%, 19%, and 18%, respectively. The possible threshold value for plasma Mg to prevent the risk of T2DM was 0.87 mmol/L. Through the quality control of the sample dietary survey data, 2469 cases were finally included for dietary analysis. And the possible threshold value for dietary Mg to prevent the risk of T2DM was 408 mg/d. Taking the recommended dietary Mg intake of 330 mg/d as the reference group, when the Mg intake reached 408 mg/d, the risk of T2DM was significantly reduced. And the average plasma Mg level of the people whose dietary intake reached 408 mg/d was 0.87 mmol/L. Conclusions: These results indicate that dietary Mg and plasma Mg have good consistency on the threshold effect of glucose parameters in women of childbearing age.

Attenuation of albumin glycation and oxidative stress by minerals and vitamins: An in vitro perspective of dual-purpose therapy

Nonenzymatic glycation of proteins is accelerated in the context of elevated blood sugar levels in diabetes. Vitamin and mineral deficiencies are strongly linked to the onset and progression of diabetes. The antiglycation ability of various water- and fat-soluble vitamins, along with trace minerals like molybdenum (Mo), manganese (Mn), magnesium (Mg), chromium, etc., have been screened using Bovine Serum Albumin (BSA) as in vitro model. BSA was incubated with methylglyoxal (MGO) at 37 °C for 48 h, along with minerals and vitamins separately, along with controls and aminoguanidine (AG) as a standard to compare the efficacy of the minerals and vitamins. Further, their effects on renal cells' (HEK-293) antioxidant potential were examined. Antiglycation potential is measured by monitoring protein glycation markers, structural and functional modifications. Some minerals, Mo, Mn, and Mg, demonstrated comparable inhibition of protein-bound carbonyl content and ß-amyloid aggregation at maximal physiological concentrations. Mo and Mg protected the thiol group and free amino acids and preserved the antioxidant potential. Vitamin E, D, B1 and B3 revealed significant glycation inhibition and improved antioxidant potential in HEK-293 cells as assessed by estimating lipid peroxidation, SOD and glyoxalase activity. These results emphasize the glycation inhibitory potential of vitamins and minerals, indicating the use of these micronutrients in the prospect of the therapeutic outlook for diabetes management.

Lower Dietary Magnesium Is Associated with a Higher Hemoglobin Glycation Index in the National Health and Nutrition Examination Survey

The data for the effect of dietary magnesium (Mg) on hemoglobin glycation index (HGI) is limited. Thus, this study aimed to examine the relationship between dietary Mg and HGI in the general population. Our research used data from the National Health and Nutrition Examination Survey from 2001 to 2002. The dietary intake of Mg was assessed by two 24-h dietary recalls. The predicted HbA1c was calculated based on fasting plasma glucose. Logistic regression and restricted cubic spline models were applied to assess the relationship between dietary Mg intake and HGI. We found a significant inverse association between dietary Mg intake and HGI (β =  - 0.00016, 95%CI: - 0.0003, - 0.00003, P = 0.019). Dose-response analyses revealed that HGI decreased with increasing intakes of Mg when reached the point above 412 mg/day. There was a linear dose-response relationship between dietary Mg intake and HGI in diabetic subjects, and there was an L-shape dose-response relationship in non-diabetic individuals. Increasing the intake of Mg might help lower the risk associated with high HGI. Further prospective studies are requested before dietary recommendations.

Effects of pistachios on glycaemic control: a systematic review and meta-analysis of randomised controlled trials

To evaluate the effects of pistachio consumption on the glucoregulatory status in individuals with a high risk of CVD, a systematic review and meta-analysis of randomised controlled trials (RCT) were conducted. Online databases including PubMed, Scopus, Web of Science and Cochrane Library were searched from inception until June 2019. Human trials that reported data for fasting blood sugar (FBS), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were included. Data were pooled using the random effect models and expressed as weighted mean difference (WMD) with 95 % CI. Eight RCTs were included in the analyses. Pistachio consumption, exchanged isocalorically for other foods, decreased FBS (WMD: -5·32 mg/dl, 95 % CI (-7·80, -2·64), P < 0·001) and insulin (WMD: -1·86 µIU/ml, 95 % CI (-3·13, -0·59), P < 0·01) concentrations in individuals with a high risk of CVD. However, no changes were observed in the levels of HOMA-IR between the groups (WMD: -0·66, 95 % CI (-1·89, 0·58), P = 0·30). Pistachio consumption may improve glucoregulatory status in individuals at risk for CVD, as evidenced by reduced FBS and insulin concentrations. However, due to the limited availability of studies with diabetic cases and relatively small sample sizes of available studies, well-designed trials with adequate sample sizes aimed at diabetic populations are recommended.

Beta Cell Dysfunction in Youth- and Adult-Onset Type 2 Diabetes: An Extensive Narrative Review with a Special Focus on the Role of Nutrients

Traditionally a disease of adults, type 2 diabetes (T2D) has been increasingly diagnosed in youth, particularly among adolescents and young adults of minority ethnic groups. Especially, during the recent COVID-19 pandemic, obesity and prediabetes have surged not only in minority ethnic groups but also in the general population, further raising T2D risk. Regarding its pathogenesis, a gradually increasing insulin resistance due to central adiposity combined with a progressively defective β-cell function are the main culprits. Especially in youth-onset T2D, a rapid β-cell activity decline has been observed, leading to higher treatment failure rates, and early complications. In addition, it is well established that both the quantity and quality of food ingested by individuals play a key role in T2D pathogenesis. A chronic imbalance between caloric intake and expenditure together with impaired micronutrient intake can lead to obesity and insulin resistance on one hand, and β-cell failure and defective insulin production on the other. This review summarizes our evolving understanding of the pathophysiological mechanisms involved in defective insulin secretion by the pancreatic islets in youth- and adult-onset T2D and, further, of the role various micronutrients play in these pathomechanisms. This knowledge is essential if we are to curtail the serious long-term complications of T2D both in pediatric and adult populations.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

Hypomagnesemia and Cardiovascular Risk in Type 2 Diabetes

Hypomagnesemia is tenfold more common in individuals with type 2 diabetes (T2D), compared to the healthy population. Factors that are involved in this high prevalence are low Mg2+ intake, gut microbiome composition, medication use and presumably genetics. Hypomagnesemia is associated with insulin resistance, which subsequently increases the risk to develop T2D or deteriorates glycaemic control in existing diabetes. Mg2+ supplementation decreases T2D associated features like dyslipidaemia and inflammation; which are important risk factors for cardiovascular disease (CVD). Epidemiological studies have shown an inverse association between serum Mg2+ and the risk to develop heart failure (HF), atrial fibrillation (AF) and microvascular disease in T2D. The potential protective effect of Mg2+ on HF and AF may be explained by reduced oxidative stress, fibrosis and electrical remodeling in the heart. In microvascular disease, Mg2+ reduces the detrimental effects of hyperglycemia and improves endothelial dysfunction. Though, clinical studies assessing the effect of long-term Mg2+ supplementation on CVD incidents are lacking and gaps remain on how Mg2+ may reduce CVD risk in T2D. Despite the high prevalence of hypomagnesemia in people with T2D, routine screening of Mg2+ deficiency to provide Mg2+ supplementation when needed is not implemented in clinical care as sufficient clinical evidence is lacking. In conclusion, hypomagnesemia is common in people with T2D and is both involved as cause, probably through molecular mechanisms leading to insulin resistance, and consequence and is prospectively associated with development of HF, AF and microvascular complications. Whether long-term supplementation of Mg2+ is beneficial, however, remains to be determined.

Herbal Sources of Magnesium as a Promising Multifaceted Intervention for the Management of COVID-19

The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization (WHO), and it affected all human groups. Severe COVID-19 is characterized by cytokine storms, which can lead to multiorgan failure and death, although fever and cough are the most typical symptoms of mild COVID-19. Plant-based diets provide a 73% lower risk of moderate-to-severe COVID-19. Additionally, the association between low levels of some micronutrients and the adverse clinical consequences of COVID-19 has been demonstrated. So, nutritional therapy can become part of patient care for the survival of this life-threatening disease (COVID-19) also short-term recovery. Magnesium as an essential micronutrient due to its anti-inflammatory and beneficial effects can effectively prevent COVID-19 pandemic by playing a role in the treatment of comorbidities such as diabetes and cardiovascular disorders as major risk factors for mortality. Sufficient magnesium to stay healthy is provided by a proper daily diet, and there is usually no need to take magnesium supplements. Considering that almost half of the dietary magnesium comes from fruits, vegetables, nuts, and grains, it seems necessary to pay attention to the consumption of edible plants containing sufficient magnesium as part of the diet to prevent severe COVID-19. In this study, we have described the beneficial effects of sufficient magnesium levels to control COVID-19 and the importance of plant-based magnesium-rich diets. Additionally, we have listed some edible magnesium-rich plants.

Active commuting, commuting modes, and the risk of diabetes: 14-year follow-up data from the Hisayama Study

Aims/Introduction

We aimed to investigate the association of active commuting (cycling or walking to work), as well as the association of the individual commuting modes, with the risk of diabetes in a prospective cohort of community‐dwelling adults in Japan.

Material and Methods

A total of 1,270 residents aged 40–79 years were followed up for a median of 14 years. Active commuting was defined as either cycling or walking to work. A Cox proportional hazards model was used to examine the association of active commuting with the risk of diabetes. Associations for different forms of active commuting (cycling, walking and mixed modes of cycling or walking with non‐active components) were also examined.

Results

During the follow‐up period, 191 participants developed diabetes. Active commuting was associated with a lower risk of diabetes than non‐active commuting after adjustment for potential confounders (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.31–0.92). With regard to the commuting modes, the risk of diabetes was significantly lower in individuals who commuted by cycling alone (HR 0.46, 95% CI 0.22–0.98), and tended to be lower in individuals who commuted by walking alone (HR 0.14, 95% CI 0.02–1.02) compared with that in individuals with non‐active commuting. Meanwhile, no significant associations were observed for the mixed mode of walking and non‐active commuting (HR 1.69, 95% CI 0.77–3.71).

Conclusions

Active commuting, particularly that consisting exclusively of cycling or walking, was associated with a reduced risk of diabetes. Our findings support a public health policy that promotes the choice of active commuting for the prevention of diabetes.

Association between Dietary Magnesium Intake and Glycemic Markers in Ghanaian Women of Reproductive Age: A Pilot Cross-Sectional Study

Low magnesium intake has been shown to be associated with an increased risk of type 2 diabetes mellitus (T2DM) in several studies conducted in high-income countries. However, very few studies have been performed in Africa, where many countries have a growing rate of T2DM. We conducted a pilot cross-sectional study among 63 women in Ghana to investigate the association between magnesium intake and glycemic markers. We assessed dietary magnesium using a food frequency questionnaire and glycemic markers using fasting blood glucose and glycated hemoglobin A1c (HbA1c). Our findings showed that the mean magnesium intake was 200 ± 116 mg/day. The prevalence of T2DM was 5% by measuring fasting blood glucose and 8% by measuring HbA1c. Unadjusted linear regression models revealed that higher magnesium intake significantly predicted higher fasting blood glucose levels (β = 0.31; 95% CI: 0.07, 0.55; p = 0.01) and HbA1c levels (β = 0.26; 95% CI: 0.01, 0.51; p = 0.04). In adjusted analyses, magnesium intake was no longer significantly associated with either fasting blood glucose levels (β = 0.22; 95% CI: −0.03, 0.46; p = 0.08) or HbA1c levels (β = 0.15; 95% CI: −0.08, 0.39; p = 0.20). In conclusion, our study did not show a significant association between magnesium intake and glycemic markers in women of reproductive age in Ghana. The results of this study need to be further substantiated because this was the first study to examine magnesium intake and glycemic markers in this population in Africa.

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

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

Changes in Dietary Magnesium Intake and Risk of Type 2 Diabetes Mellitus in Middle School Students: Using Data from the HEALTHY Study

BACKGROUND

The HEALTHY Study was a multicomponent school-based intervention, designed to prevent type 2 diabetes mellitus (T2DM) in middle-school students.

OBJECTIVES

We examined whether the difference in dietary magnesium intake, BMI percentile, and plasma glucose and insulin concentrations from 6th to 8th grade were related in the intervention schools and in the control schools that participated in the HEALTHY Study.

METHODS

A total of 2181 ethnically diverse students, from 11.3 to 13.7 y of age, with completed dietary records, BMI percentile, and plasma glucose and insulin concentrations at 6th and 8th grades were included. Dietary magnesium intake was self-reported using the Block Kids FFQ. A hierarchical multiple regression model was used to determine whether the differences in dietary magnesium intake, BMI percentile, and plasma glucose and insulin concentrations from 6th to 8th grades were related, while adjusting for dietary calcium intake and total energy intake.

RESULTS

The difference in dietary magnesium intake was significantly related to changes in BMI percentile from 6th to 8th grade in intervention and in control schools [intervention: β: -0.07; 95% CI: -0.58, -0.02; P = 0.03; R2 (regression coefficient effect size): 0.14; 95% CI for R2: 0.10, 0.17; control: β: -0.08; 95% CI: -0.63, -0.09; P = 0.01; R2: 0.12; 95% CI for R2: 0.08, 0.15]. The difference in dietary magnesium intake was not related to plasma glucose and insulin concentrations in intervention and in control schools.

CONCLUSIONS

We conclude that a multicomponent intervention was associated with reduced risk of T2DM, and that this association may be modulated, in part, by magnesium. The differences in dietary magnesium intake from 6th to 8th grade were negatively related to changes in BMI percentile among middle-school students.

Retrospective study of factors associated with progression and remission/regression of diabetic kidney disease-hypomagnesemia was associated with progression and elevated serum alanine aminotransferase levels were associated with remission or regression

Aim

This study was aimed at retrospectively investigating some common clinical factors, including the serum level of magnesium (Mg), associated with progression and remission/regression of diabetic kidney disease (DKD).

Methods

The subjects were 690 Japanese patients with type 2 diabetes mellitus who were receiving treatment with oral antidiabetic drugs other than SGLT2 inhibitors. Routine clinical data were collected on the first and last day of the observation period. The prognosis of DKD is categorized into four stages according to the Kidney Disease Improving Global Outcomes classification. Progression was defined as transition from any of the lower three risk categories (LR, MIR, HR) at the start of the observation period, to the VHR stage/category at the end of the observation period. Remission/regression was defined as improvement of the risk category by at least one stage from the start to the end of the observation period. Factors associated with progression and regression/remission were investigated using Cox proportional hazards analysis. Furthermore, the factors associated with the annual decrease in eGFR of 5 ml/min/1.73 m² or more were examined by logistic regression analysis. Factors associated with transition of urinary protein negative to trace or positive, or transition of negative or trace to positive, were investigated by Cox proportional hazard analysis.

Results

The observation period was 2251 ± 1614 days. Age (Exp [B] = 1.10, 95% CI; 1.06-1.14; P < 0.01; 1 year old), serum Mg (Exp [B] = 0.82, 95% CI; 0.71-0.95; P < 0.01); 0.1 mg/dl), and serum HbA1c (Exp [B] = 1.03, 95% CI; 1.01-1.05; P < 0.01: 0.1%) were associated with progression of DKD; on the other hand, serum ALT was associated with the likelihood of remission/regression of DKD (Exp [B] = 1.01, 95% CI; 1.002-1.018; P < 0.05; 1 IU/L). The decline in eGFR was associated with higher HbA1c levels, hypomagnesemia, and lower ALT. The new appearance of trace or overt proteinuria was correlated with higher HbA1c levels, advancing age, hypomagnesemia and hypertriglycemia.

Conclusion

Our findings confirmed previous reports that advancing age and serum HbA1c levels were associated with an increased risk of progression of DKD. Lower serum Mg concentrations were also found to be associated with a high risk of progression of DKD, and interventional studies are needed to confirm a causal relationship. Elevated HbA1c levels and hypomagnesemia were common factors in the decline in eGFR and the appearance of trace or overt proteinuria. Lower serum ALT levels were associated with the decline in eGFR. Since serum ALT is known to decrease as the renal function deteriorates, serum ALT is considered to be a marker of renal function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-020-00483-1.

Magnesium intake is inversely associated with the risk of metabolic syndrome in the REasons for geographic and racial differences in stroke (REGARDS) cohort study

OBJECTIVE

To investigate the longitudinal association between magnesium (Mg) intake and the risk of metabolic syndrome (MetS).

METHODS

Poisson regression models with robust standard error estimation were used to examine the association between total Mg intake and the risk of MetS in 6802 participants aged ≥45 years at baseline in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Dietary data were collected using the modified Block 98 food frequency questionnaire (FFQ) at baseline and incident MetS was diagnosed during follow-up if a participant had three or more of the five components of MetS based on the harmonized definition.

RESULTS

A total of 1470 participants developed MetS during an average follow-up of 10 years. Comparing the highest quintile of total Mg intake (>437.9 mg/day) to the lowest group (<223.5 mg/day), total Mg intake had a significant inverse association with the risk of MetS [relative risk (RR) = 0.79 (0.63, 0.98), P_trend = 0.043]. Dietary Mg intake was inversely associated with MetS [RR = 0.72 (0.56, 0.91), P_trend = 0.006]. Adjusting for baseline components of MetS attenuated the associations, but the linear trends remained.

CONCLUSION

The findings from this study indicate that dietary Mg intake was inversely associated with the risk of MetS. We recommend further studies to explain the underlying mechanisms of action.

Role of Minerals and Trace Elements in Diabetes and Insulin Resistance

Minerals and trace elements are micronutrients that are essential to the human body but present only in traceable amounts. Nonetheless, they exhibit well-defined biochemical functions. Deficiencies in these micronutrients are related to widespread human health problems. This review article is focused on some of these minerals and trace element deficiencies and their consequences in diabetes and insulin resistance. The levels of trace elements vary considerably among different populations, contingent on the composition of the diet. In several Asian countries, large proportions of the population are affected by a number of micronutrient deficiencies. Local differences in selenium, zinc, copper, iron, chromium and iodine in the diet occur in both developed and developing countries, largely due to malnutrition and dependence on indigenous nutrition. These overall deficiencies and, in a few cases, excess of essential trace elements may lead to imbalances in glucose homeostasis and insulin resistance. The most extensive problems affecting one billion people or more worldwide are associated with inadequate supply of a number of minerals and trace elements including iodine, selenium, zinc, calcium, chromium, cobalt, iron, boron and magnesium. This review comprises various randomized controlled trials, cohort and case-controlled studies, and observational and laboratory-based studies with substantial outcomes of micronutrient deficiencies on diabetes and insulin resistance in diverse racial inhabitants from parts of Asia, Africa, and North America. Changes in these micronutrient levels in the serum and urine of subjects may indicate the trajectory toward metabolic changes, oxidative stress and provide disease-relevant information.

Association of magnesium intake with type 2 diabetes and total stroke: an updated systematic review and meta-analysis

OBJECTIVE

The detailed associations between type 2 diabetes (T2D) and total stroke and magnesium intake as well as the dose-response trend should be updated in a timely manner.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

PubMed, Embase, Cochrane Library, Web of Science and ClinicalTrials.gov were rigorously searched from inception to 15 March 2019.

ELIGIBILITY CRITERIA

Prospective cohort studies investigating these two diseases were included.

DATA SYNTHESIS

Relative risk (RR) and 95% CI in random effects models as well as absolute risk (AR) were pooled to calculate the risk of T2D and stroke. Methodological quality was assessed by the Newcastle-Ottawa Scale.

RESULTS

Forty-one studies involving 53 cohorts were included. The magnitude of the risk was significantly reduced by 22% for T2D (RR 0.78 (95% CI 0.75 to 0.81); p<0.001; AR reduction 0.120%), 11% for total stroke (RR 0.89 (95% CI 0.83 to 0.94); p<0.001; AR reduction 0.281%) and 12% for ischaemic stroke (RR 0.88 (95% CI 0.81 to 0.95); p=0.001; AR reduction 0.246%) when comparing the highest magnesium intake to the lowest. The inverse association still existed when studies on T2D were adjusted for cereal fibre (RR 0.79; p<0.001) and those on total stroke were adjusted for calcium (RR 0.89; p=0.040). Subgroup analyses suggested that the risk for total and ischaemic stroke was significantly decreased in females, participants with ≥25 mg/m² body mass index and those with ≥12-year follow-up; the reduced risk in Asians was not as notable as that in North American and European populations.

CONCLUSIONS

Magnesium intake has significantly inverse associations with T2D and total stroke in a dose-dependent manner. Feasible magnesium-rich dietary patterns may be highly beneficial for specific populations and could be highlighted in the primary T2D and total stroke prevention strategies disseminated to the public.

PROSPERO REGISTRATION NUMBER

CRD42018092690.

Natural Magnesium-Enriched Deep-Sea Water Improves Insulin Resistance and the Lipid Profile of Prediabetic Adults: A Randomized, Double-Blinded Crossover Trial

Previous in vitro and in vivo studies have shown that the antidiabetic effect of balanced deep-sea water (BDSW) works through the suppression of hyperglycemia and improvement of glucose tolerance. Based on these promising results, we conducted an eight week randomized, double-blinded crossover trial of the effects of BDSW in prediabetic adults. The subjects consumed 440 mL of BDSW (hardness 4000) per day, and maintained an otherwise normal lifestyle and diet throughout. Efficacy assessments were made by measuring fasting glucose, postprandial glucose, fasting insulin, homeostasis model assessment for insulin resistance (HOMA-IR), C-peptide, glycosylated hemoglobin, lipid metabolism indicators, and physical metrics, along with safety assessments. Fasting insulin and HOMA-IR values of the BDSW group were significantly lower than those of the placebo group after eight weeks of BDSW ingestion. Total cholesterol and low-density lipoprotein–cholesterol were also significantly decreased in the BDSW group after eight weeks of BDSW ingestion compared with the placebo group. There were no statistically and clinically meaningful changes in adverse events, physical examination, laboratory medicine examination, or vital signs of the BDSW intake group. These results suggested that the intake of BDSW in prediabetic adults can improve glucose metabolism and lipid profiles and is safe for human consumption.

Reduced Insulin Resistance Partly Mediated the Association of High Dietary Magnesium Intake with Less Metabolic Syndrome in a Large Chinese Population

PURPOSE

High dietary magnesium intake may reduce insulin resistance (IR) and metabolic syndrome (MetS). The aim of the cross-sectional analysis was to evaluate the association between dietary magnesium intake, IR, and MetS using data from China Health and Nutrition Survey.

METHODS

Dietary magnesium intake was defined as daily dietary magnesium intake divided by body weight. Logistic regression analysis was used to calculate the odds ratio (OR) for IR and the prevalence of MetS across the quartile categories of dietary magnesium intake. In addition, we used the macro PROCESS to perform the mediation analyses.

RESULTS

A total of 8120 participants were included in the final analysis. We found a significant negative association between dietary magnesium intake and IR, the multivariable-adjusted OR for HOMA-IR comparing the highest to the lowest quartile of dietary magnesium intake was 0.435 (95% confidence intervals [CI] 0.376 to 0.502). The prevalence of the MetS was 38.6%, 28.9%, 22.5%, and 16.5% for increasing quartiles of dietary magnesium intake (p <0.001). The mediation model analysis displayed that insulin resistance mediated the effect of dietary magnesium on MetS. The direct effect and indirect effect of dietary magnesium on MetS were found significant, and the calculated percentage of mediation by insulin resistance was 19.6%.

CONCLUSION

Our study demonstrated a significant and independent negative relationship among weight-adjusted dietary magnesium intake, HOMA-IR, and MetS in a large Chinese population. IR partly mediated the relationship between dietary magnesium intake and MetS.

Differences in Serum Magnesium Levels in Diabetic and Non-Diabetic Patients Following One-Anastomosis Gastric Bypass

Patients with obesity and type 2 diabetes mellitus (T2DM) are regarded to have reduced serum magnesium (Mg) concentrations. We aimed to assess the changes in serum Mg concentrations at 12-month follow-up in patients, with and without T2DM, who underwent one anastomosis gastric bypass surgery. Overall, 50 patients (80% female, age 42.2 (12.5) years) with morbid obesity (mean baseline BMI 43.8 (4.3) kg/m2) were included in the analysis. Half of the included patients had T2DM diagnosed at baseline, and these patients showed lower serum Mg concentration (0.78 (0.07)) vs. 0.83 (0.05) mmol/L; p = 0.006), higher blood glucose levels (129.9 (41.3) vs. 87.6 (8.1) mg/dL; p < 0.001) as well as HbA1c concentrations (6.7 (1.4) vs. 5.3 (0.5)%; p < 0.001). During follow-up, BMI and glucose levels showed a decrease; however, serum Mg levels remained stable. At baseline 42% of patients were found to be Mg deficient, which was reduced to 33% at six months and to 30% at 12 months follow-up. Moreover, patients with T2DM had an odds ratio of 9.5 (95% CI = 3.0-29.7; p < 0.001) for magnesium deficiency when compared to patients without T2DM. Further research into the role of Mg and its role in T2DM and other obesity-related comorbidities are needed.

Dietary Approaches to Stop Hypertension (DASH): potential mechanisms of action against risk factors of the metabolic syndrome

The metabolic syndrome is a cluster of disorders dominated by abdominal obesity, hypertriacylglycerolaemia, low HDL-cholesterol, high blood pressure and high fasting glucose. Diet modification is a safe and effective way to treat the metabolic syndrome. Dietary Approaches to Stop Hypertension (DASH) is a dietary pattern rich in fruits, vegetables and low-fat dairy products, and low in meats and sweets. DASH provides good amounts of fibre, K, Ca and Mg, and limited quantities of total fat, saturated fat, cholesterol and Na. Although DASH was initially designed for the prevention or control of hypertension, using a DASH diet has other metabolic benefits. In the present review, the effect of each dietary component of DASH on the risk factors of the metabolic syndrome is discussed. Due to limited fat and high fibre and Ca content, individuals on the DASH diet are less prone to overweight and obesity and possess lower concentrations of total and LDL-cholesterol although changes in TAG and HDL-cholesterol have been less significant and available evidence in this regard is still inconclusive. Moreover, high amounts of fruit and vegetables in DASH provide great quantities of K, Mg and fibre, all of which have been shown to reduce blood pressure. K, Mg, fibre and antioxidants have also been effective in correcting glucose and insulin abnormalities. Evidence is provided from cross-sectional investigations, cohort studies and randomised controlled trials, and, where available, from published meta-analyses. Mechanisms are described according to human studies and, in the case of a lack of evidence, from animal and cell culture investigations.

Objectively measured sedentary time and diabetes mellitus in a general Japanese population: The Hisayama Study

AIMS/INTRODUCTION

The present study aimed to examine cross-sectional associations between objectively measured sedentary time and the prevalence of diabetes mellitus in a general Japanese population, and to elucidate possible mediating roles of diet, obesity and insulin resistance in this relationship.

MATERIALS AND METHODS

A total of 1,758 community-dwelling individuals aged 40-79 years wore an accelerometer for ≥7 days and underwent a comprehensive health examination in 2012. Diabetes mellitus was diagnosed by a 75-g oral glucose tolerance test. The associations of sedentary time with the presence of diabetes mellitus and the levels of the homeostasis model assessment of insulin resistance were estimated by logistic and linear regression models.

RESULTS

After adjustment for demographic and lifestyle factors including moderate-to-vigorous physical activity, participants who spent ≥10 h in sedentary time had a significantly higher odds ratio of the presence of diabetes than those who spent <6 h in sedentary time (odds ratio 1.84, 95% confidence interval 1.02-3.31). This significant association remained after adjusting for overall and central obesity (as measured by body mass index and waist circumference), but weakened after adjusting for dietary energy intake or homeostasis model assessment of insulin resistance. Sedentary time was positively associated with homeostasis model assessment of insulin resistance levels among non-diabetic participants after adjusted for obesity or energy intake (P for trend <0.01).

CONCLUSIONS

Longer sedentary time was associated with a higher prevalence of diabetes mellitus in a general Japanese population. Insulin resistance appeared to be mainly involved in this association. These results highlight the importance of public health strategies targeting reductions in sedentary time for the primary prevention of diabetes mellitus.

No Difference in Magnesium Intake between Obese Women and Healthy Controls

Magnesium is a predominantly intracellular ion and plays an important role in energy metabolism and in the maintenance of energy homeostasis. This study aimed to estimate the dietary intake of magnesium and its association with adiposity parameters in obese women. This cross-sectional study included 125 women, aged between 20 and 50 years, who were divided into two groups: obese group (n = 62) and control group (n = 63). The control group was age-matched. Adiposity parameters determined were weight, body mass index and waist circumference as well as the intake of calories, macronutrients, and magnesium were calculated. The cut-off for obesity was body mass index between 30.0 and 39.9 kg/m² and for control group was between 18.5 and 24.9 kg/m² Food intake was calculated using 3-day food records, and energy consumption as well as the intake of macronutrients and magnesium was calculated using the NutWin software version 1.5. The reference values used were the Acceptable Macronutrient Distribution Range for macronutrients and the Estimated Average Requirement (EAR) for magnesium. The average levels of magnesium found in the diet were lower than those recommended (169.1 ± 64.5 mg Mg/day and 158.5 ± 42.9 mg Mg/day, for obese women and control group, respectively) and the differences between the groups were not statistically different (p > 0.05). The correlation analysis indicated that the association between the dietary intake of magnesium and adiposity was not significant. The results of this study indicate that dietary magnesium does not influence the adiposity parameters in obese women.

[Nutrition for diabetic patients (Update 2019)]

Evidence demonstrates that medical diabetes treatment has to be accompanied by lifestyle modifications. Structured nutrition interventions and increased physical activity will help patients to normalise, respectively maintain their body weight.The main target of a medical nutrition therapy aims at achieving normal or nearly normal blood glucose levels, prevention of delay of diabetes associated complications.

Association Between Magnesium Status, Dietary Magnesium Intake, and Metabolic Control in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Hypomagnesemia could worsen glycemic control by impairing insulin release and promoting insulin resistance. On the contrary, type 2 diabetes mellitus (T2DM) may induce and/or exacerbate low serum magnesium levels, and this could, in turn, worsen glycemic control of diabetes.

OBJECTIVE

The aim of this study was to investigate the relationship between serum magnesium level, dietary magnesium intake, and metabolic control parameters in patients with T2DM.

METHODS

The study included 119 patients with T2DM (26 male, 93 female; mean age 54.7 ± 8.4 years). Serum magnesium level was measured by spectrophotometric method. Magnesium intake was assessed by food frequency questionnaire. Anthropometric measurements were taken. The General Linear Model procedure was applied to determine the relationship of serum magnesium with quantitative variables.

RESULTS

Of the 119 patients, 23.5% of the patients had inadequate magnesium intake (lower than 67% of the recommended daily allowance), and 18.5% had hypomagnesemia. In patients with hypomagnesemia (< 0.75 mmol/l), serum levels of fasting plasma glucose (FPG), postprandial plasma glucose (PPG), and serum glycosylated hemoglobin (HbA1c) were higher compared to patients with normomagnesemia. FPG levels were significantly higher in patients with hypomagnesemia in Model 1 (179.0 ± 64.9 vs. 148.7 ± 52.0 mg/dl, p = 0.009) but the significance disappeared in other models. PPG levels were significantly higher in patients with hypomagnesemia in all models (287.9 ± 108.4 vs. 226.8 ± 89.4 mg/dl, p = 0.006 for Model 1, p = 0.027 for Model 2, p = 0.016 for Model 3). Serum HbA1c levels were significantly higher in patients with hypomagnesemia, and this significance proceeded (8.0 ± 1.9% vs. 6.5 ± 1.2%, p = 0.000 for all models). Body fat mass was significantly higher in patients with hypomagnesemia as compared to patients with normomagnesemia in model 3 (35.4 ± 9.4 kg, 34.6 ± 10.2 kg; p = 0.034). Dietary magnesium intake was not significantly associated with either metabolic parameters or anthropometric measurements.

CONCLUSION

Hypomagnesemia in T2DM is directly associated with poor metabolic control. Clinical assessment should, therefore, focus on augmentation of magnesium status and adequate magnesium intake in patients with T2DM.

The Resulting Variation in Nutrient Intake With the Inclusion of Walnuts in the Diets of Adults at Risk for Type 2 Diabetes: A Randomized, Controlled, Crossover Trial

PURPOSE

We previously demonstrated that including walnuts in the diets of adults at risk for type 2 diabetes mellitus (T2DM) led to improved overall diet quality. This report examines the specific changes in their nutrient intake.

DESIGN

This was a randomized, controlled, modified Latin square parallel design trial with 2 treatment arms. Participants were randomized to walnut intake with, or without, dietary advice to regulate caloric intake. Within each treatment arm, they were further randomized to one of 2 sequence permutations (walnut-included/walnut-excluded or walnut-excluded/walnut-included diet), with a 3-month washout between treatment phases.

SETTING

Community hospital in Lower Naugatuck Valley in Connecticut.

PARTICIPANTS

Cohort of 112 participants (31 men and 81 women) at risk for T2DM.

INTERVENTION

Participants included 56 g (366 kcal) of walnuts in their daily diets for 6 months.

MEASURES

Nutrient intake was assessed using web-based Automated Self-Administered 24-Hour Dietary Assessment.

ANALYSIS

Data were analyzed using generalized linear models.

RESULTS

Walnut inclusion led to increased intake of total fat, calcium, magnesium, thiamin, total saturated fatty acids, and monounsaturated and polyunsaturated fatty acids (379.0 ± 90.3 g vs -136.5 ± 92.7 g, P < .01; 230.7 ± 114.2 mg vs -95.2 ± 117.4 mg, P = .05; 111.0 ± 33.9 mg vs -32.3 ± 34.9 mg, P < .01; 0.28 ± 0.2 mg vs -0.47 ± 0.2 mg, P = .02; 8.6 ± 3.4 g vs -1.1 ± 3.5 g, P =.05; 6.3 ± 3.9 g vs -6.3 ± 4.0 g, P = .03; and 25.4 ± 4.0 vs -6.6 ± 4.2 g, P < .01, respectively). Vitamin C intake decreased (-65.3 ± 55.3 mg vs 98.9 ± 56.8 mg, P = .04). Protein intake increased from baseline with the inclusion of walnuts (20.0 ± 8.8 g, P < .05). Walnut inclusion led to an increase in total calories consumed when caloric intake is not regulated.

CONCLUSION

Including walnuts in the diets of these adults led to increased dietary intake of some nutrients associated with lower risk of developing T2DM and other cardiometabolic risk factors.

A new method to evaluate the dose-effect relationship of a TCM formula Gegen Qinlian Decoction: "Focus" mode of integrated biomarkers

It is difficult to accurately evaluate the efficacy of traditional Chinese medicine (TCM), which leads to the uncertainty and complexity of dose-effect analysis. In this study we established the "Focus" mode of biomarkers to characterize the dose-effect relationship of Gegen Qinlian Decoction (GQD), a TCM formula for treating type 2 diabetes mellitus (2-DM). A rat model of 2-DM was established through high fat diet feeding combined with low-dose STZ injection. Rats with 2-DM were administered high, middle or low doses (6.785, 4.071, 1.357 mg·kg^-1·d^-1, respectively) of GQD extract for 60 d. Metformin (300 mg·kg^-1·d^-1) was taken as the positive control. Blood samples were collected to assess serum biochemical indexes and metabolic profiling. After "Focus" analysis, the biochemical index triglycerides (TG) and insulin sensitivity (ISI) were identified as focused integrated biomarkers (FIBs), while arachidonic acid and docosatetraenoic acid were the metabolic FIBs. Dose-effect relationship curves of GQD were built based on these types of FIBs. Furthermore, the two dose-effect relationship curves showed similar trends with the middle dosage displaying the greatest efficacy, suggesting that insulin function and arachidonic acid metabolism played important roles in 2-DM and the responses to GQD. The metabolic FIB docosatetraenoic should be further explored for understanding its involvement in the process of 2-DM occurrence and the treatment. This "Focus" mode provides a novel strategy to evaluate the dose-effect relationship of a TCM. The system and concepts established here may also be applicable for assessing the dose-effect relationships of Western medicines.

Association between Toenail Magnesium and Type 2 Diabetes in Chinese Adults

Previous studies have showed an inverse association between magnesium level and type 2 diabetes, but the results are inconsistent, and the evidence relates only to dietary and serum magnesium. Moreover, it is not certain how these findings are applicable to Asian people. This study was designed to examine the association between toenail magnesium and type 2 diabetes in Chinese adults. The sample was 5683 adults aged 18 years or older from the 2009 China Health and Nutrition Survey. We used hemoglobin A1c equal to or greater than 6.5% as the diagnostic criterion for type 2 diabetes. Inductively coupled plasma–mass spectrometry determined toenail magnesium. Mean toenail magnesium in participants with and without type 2 diabetes was 263.0 ± 170.9 and 282.3 ± 191.9 micrograms per gram, respectively. The multivariable-adjusted odds ratio for type 2 diabetes comparing the highest to the lowest quartile of toenail magnesium was 0.72 (95% confidence interval, 0.52–0.99). We found a statistically significant interaction between toenail magnesium and geographic region on the prevalence of type 2 diabetes (p for interaction = 0.009). Our findings suggest that toenail magnesium is inversely associated with the prevalence of type 2 diabetes. Promoting the intake of magnesium-rich foods may bring considerable benefits for the prevention of type 2 diabetes, especially in those at high risk.

Dietary magnesium intake and the risk of cardiovascular disease, type 2 diabetes, and all-cause mortality: a dose-response meta-analysis of prospective cohort studies

BACKGROUND

Although studies have examined the association between dietary magnesium intake and health outcome, the results are inconclusive. Here, we conducted a dose-response meta-analysis of prospective cohort studies in order to investigate the correlation between magnesium intake and the risk of cardiovascular disease (CVD), type 2 diabetes (T2D), and all-cause mortality.

METHODS

PubMed, EMBASE, and Web of Science were searched for articles that contained risk estimates for the outcomes of interest and were published through May 31, 2016. The pooled results were analyzed using a random-effects model.

RESULTS

Forty prospective cohort studies totaling more than 1 million participants were included in the analysis. During the follow-up periods (ranging from 4 to 30 years), 7678 cases of CVD, 6845 cases of coronary heart disease (CHD), 701 cases of heart failure, 14,755 cases of stroke, 26,299 cases of T2D, and 10,983 deaths were reported. No significant association was observed between increasing dietary magnesium intake (per 100 mg/day increment) and the risk of total CVD (RR: 0.99; 95% CI, 0.88-1.10) or CHD (RR: 0.92; 95% CI, 0.85-1.01). However, the same incremental increase in magnesium intake was associated with a 22% reduction in the risk of heart failure (RR: 0.78; 95% CI, 0.69-0.89) and a 7% reduction in the risk of stroke (RR: 0.93; 95% CI, 0.89-0.97). Moreover, the summary relative risks of T2D and mortality per 100 mg/day increment in magnesium intake were 0.81 (95% CI, 0.77-0.86) and 0.90 (95% CI, 0.81-0.99), respectively.

CONCLUSIONS

Increasing dietary magnesium intake is associated with a reduced risk of stroke, heart failure, diabetes, and all-cause mortality, but not CHD or total CVD. These findings support the notion that increasing dietary magnesium might provide health benefits.

Dose-Response Relationship between Dietary Magnesium Intake and Risk of Type 2 Diabetes Mellitus: A Systematic Review and Meta-Regression Analysis of Prospective Cohort Studies

The epidemiological evidence for a dose-response relationship between magnesium intake and risk of type 2 diabetes mellitus (T2D) is sparse. The aim of the study was to summarize the evidence for the association of dietary magnesium intake with risk of T2D and evaluate the dose-response relationship. We conducted a systematic review and meta-analysis of prospective cohort studies that reported dietary magnesium intake and risk of incident T2D. We identified relevant studies by searching major scientific literature databases and grey literature resources from their inception to February 2016. We included cohort studies that provided risk ratios, i.e., relative risks (RRs), odds ratios (ORs) or hazard ratios (HRs), for T2D. Linear dose-response relationships were assessed using random-effects meta-regression. Potential nonlinear associations were evaluated using restricted cubic splines. A total of 25 studies met the eligibility criteria. These studies comprised 637,922 individuals including 26,828 with a T2D diagnosis. Compared with the lowest magnesium consumption group in the population, the risk of T2D was reduced by 17% across all the studies; 19% in women and 16% in men. A statistically significant linear dose-response relationship was found between incremental magnesium intake and T2D risk. After adjusting for age and body mass index, the risk of T2D incidence was reduced by 8%–13% for per 100 mg/day increment in dietary magnesium intake. There was no evidence to support a nonlinear dose-response relationship between dietary magnesium intake and T2D risk. The combined data supports a role for magnesium in reducing risk of T2D, with a statistically significant linear dose-response pattern within the reference dose range of dietary intake among Asian and US populations. The evidence from Europe and black people is limited and more prospective studies are needed for the two subgroups.

Association among dietary magnesium, serum magnesium, and diabetes: a cross-sectional study in middle-aged and older adults

BACKGROUND

A number of studies have reported the association between magnesium (Mg) and diabetes. However, the various conclusions were inconsistent and the data on the Chinese population was limited. The objective of this study was to evaluate the association among dietary Mg, serum Mg, and diabetes in Chinese adults.

METHODS

A cross-sectional study that contained 2904 subjects was conducted. Biochemical test results and dietary intakes of subjects were collected for analysis. The adjusted odds ratios (ORs) and the corresponding 95 % confidence intervals (95 % CIs) were used to determine the relationship between Mg status and diabetes by logistic regression.

RESULTS

The prevalence of diabetes of the investigated population was 10.1 %. Dietary Mg intake was not significantly correlated with diabetes (P > 0.05). The significant negative association between serum Mg and diabetes existed, and the multivariate adjusted OR was 0.34 (95 % CI 0.24, 0.49) in model 3 for the highest quartile of serum Mg compared with the lowest. The P values for trend were all less than 0.001 for the relationship between serum Mg and diabetes. Dietary Mg intake and serum Mg were not significantly correlated in the diabetes population (P = 0.936).

CONCLUSIONS

Dietary Mg was not significantly correlated with diabetes, while serum Mg was inversely correlated with diabetes in the Chinese population. Meanwhile, dietary Mg intake and serum Mg were not significantly correlated in the diabetes population.

Investigation of non-covalent complexations of Ca(II) and Mg(II) ions with insulin by using electrospray ionization mass spectrometry

RATIONALE

Insulin is a peptide hormone secreted by pancreatic β-cells. Ca(II) and Mg(II) ions play an important role in the secretion of insulin. There is no study about a direct complexation of Ca(II) or Mg(II) with insulin and their equilibrium constants. Electrospray ionization mass spectrometry (ESI-MS) is a practical method for the monitoring of non-covalent complexes such as Ca(II)-insulin and Mg(II)-insulin. Here, the equilibrium constants of Ca(II)-insulin and Mg(II)-insulin non-covalent complexes have been calculated after ESI-MS measurements in aqueous solutions.

METHODS

The effects of pH, competitive binding, ion exchange, and Na(I) and K(I) ions on Ca(II)-insulin and Mg(II)-insulin complexation have been examined by measuring by ESI-MS. The dissociation equilibrium constants (K1 and K2 ) of Ca(II)-insulin and Mg(II)-insulin complexes were calculated from the binomial graph derived from the ESI-MS normalized peak intensities. The MS/MS spectra of the complexes have been examined.

RESULTS

The dissociation equilibrium constants were found to K1 : 1.29 × 10(-4)  M and K2 : 9.69 × 10(-4)  M for the Ca(II)-insulin complexes, and K1 : 1.37 × 10(-4)  M and K2 : 9.12 × 10(-4)  M for Mg(II)-insulin complexes. Ca(II) ions have higher complexation capability with insulin than Mg(II) ions.

CONCLUSIONS

The binding equilibrium constants of Ca(II)- and Mg(II)-insulin non-covalent complexes have been determined successfully by ESI-MS. Ca(II) and Mg(II) ions are involved in the insulin secretion by forming non-covalent complexes. Copyright © 2016 John Wiley & Sons, Ltd.

[Nutrition for diabetic patients]

Evidence demonstrates that medical diabetes treatment has to be accompanied by lifestyle modifications. Structured nutrition interventions and increased physical activity will help patients to normalise, respectively maintain their body weight. The main target of a diabetes therapy is aimed at achieving normal or nearly normal blood glucose levels. Reaching this goal may be facilitated by the following nutritional patterns: Using mainly carbohydrates from vegetables, whole grains, legumes and fruits, Restriction of mono- and disaccharides are often important factors in normalising body weight and blood glucose, Reduction of dietary fat could be indicated. However, the primary goal is the limitation of saturated fatty acids which to high percentage are consumed with animal products. There is not sufficient evidence to recommend a dietary protein consumption of more than 20% of energy intake. Individuals with diabetes should be aware of the importance of acquiring daily vitamin and mineral requirements. Natural food sources should be preferred.

Prevalence of Thrombocytopenia and Its Association with Serum Magnesium

The present study aimed to investigate the prevalence of thrombocytopenia and its association with serum magnesium in a nationally representative cohort. A total of 8478 participants aged 18 years and over were recruited in a cross-sectional survey. Thrombocytopenia was defined as platelet count less than 150 × 10(9)/L. Multivariable logistic regression models were applied to examine the association between serum magnesium and thrombocytopenia. The prevalence of thrombocytopenia in total was 16.5% with 18.8% for men and 14.4% for women (P < 0.0001), respectively. Compared with men in the first quartile of serum magnesium, the odds ratios (ORs) and 95% confidence intervals (CIs) for those in the second, third, and fourth quartiles of serum magnesium were 0.96 (0.75, 1.21), 0.78 (0.62, 0.98), and 0.82 (0.65, 1.04), respectively, after adjusting for multiple confounders. Likewise, the corresponding ORs (95% CIs) were 0.80 (0.63, 1.01), 0.79 (0.62, 0.99), and 0.65 (0.51, 0.84) in women. When serum magnesium was treated as a continuous variable, each one standard deviation increase of magnesium was associated with 12 and 8% lower risk of thrombocytopenia in men and women, respectively. Serum magnesium was inversely associated with thrombocytopenia, and the association was slightly different in men compared with that in women.

Dietary magnesium intake and the risk of diabetes in the Japanese community: results from the Takayama study

PURPOSE

Several experimental studies showed that magnesium intake improved insulin resistance and glucose uptake in diabetes patients. However, epidemiological studies on the association between magnesium intake and diabetes risk have yielded inconsistent results. We investigated whether magnesium intake is related to the risk of developing diabetes in a population-based cohort study in Japan.

METHODS

Study subjects were participants in the Takayama study. A total of 13,525 residents in Takayama City, Japan, responded to a self-administered questionnaire in 1992 and to a follow-up questionnaire seeking information about diabetes in 2002. Magnesium and other nutrient intakes were estimated from a validated food frequency questionnaire administered at the baseline.

RESULTS

During a follow-up of 10 years, 438 subjects reported diabetes newly diagnosed by physician. Compared with women in the low quartile of magnesium intake, women in the high quartile were at a significantly reduced risk of diabetes (HR 0.50; 95 % CI 0.30-0.84; P-trend 0.005) after adjustments for covariates. In men, there was no association between magnesium intake and the risk of diabetes.

CONCLUSION

These results suggest that diets with a high intake of magnesium may decrease the risk of diabetes in women.

Association of Serum Magnesium Deficiency with Insulin Resistance in Type 2 Diabetes Mellitus

Background:

Insulin resistance (IR) is the key pathophysiological defect that leads to the development of type 2 diabetes mellitus. The purpose of this study was to estimate serum magnesium level and insulin sensitivity indices among type 2 diabetes mellitus patients and to see an association between them.

Methods:

This study was carried out among 38 type 2 diabetic patients and forty age and sex matched controls. Serum fasting glucose, magnesium, insulin, urea, and creatinine levels were estimated. Insulin sensitivity indices, homeostasis model assessment for insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) levels were calculated as per formulae.

Results:

A highly significant low serum magnesium level was found in diabetic subjects as compared to the controls. Statistically significant high HOMA levels (>2.6) and low QUICKI levels (<0.33) were found among the case group. An inverse, statistically significant correlation was found between serum magnesium and fasting insulin level. A highly statistically significant inverse correlation was found between serum magnesium and HOMA level, and a positive correlation was found between serum magnesium and QUICKI level, that is, serum magnesium level decreases with increase in IR. A strong association was also found between fasting serum insulin level and insulin sensitivity indices.

Conclusion:

This study showed a lower serum magnesium level in diabetic patients compared to control. A strong association was also found between serum magnesium level and insulin sensitivity indices. For proper management of type 2 diabetes, it may, therefore, be necessary to treat hypomagnesemia in these patients.

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.

Intakes of magnesium, potassium, and calcium and the risk of stroke among men

BACKGROUND

Intakes of magnesium, potassium, and calcium have been inversely associated with the incidence of hypertension, a known risk factor for stroke. However, only a few studies have examined intakes of these cations in relation to risk of stroke.

AIM

The aim of this study was to investigate whether high intake of magnesium, potassium, and calcium is associated with reduced stroke risk among men.

METHODS

We prospectively examined the associations between intakes of magnesium, potassium, and calcium from diet and supplements, and the risk of incident stroke among 42 669 men in the Health Professionals Follow-up Study, aged 40 to 75 years and free of diagnosed cardiovascular disease and cancer at baseline in 1986. We calculated the hazard ratio of total, ischemic, and haemorrhagic strokes by quintiles of each cation intake, and of a combined dietary score of all three cations, using multivariate Cox proportional hazard models.

RESULTS

During 24 years of follow-up, 1547 total stroke events were documented. In multivariate analyses, the relative risks and 95% confidence intervals of total stroke for men in the highest vs. lowest quintile were 0·87 (95% confidence interval, 0·74-1·02; P, trend = 0·04) for dietary magnesium, 0·89 (95% confidence interval, 0·76-1·05; P, trend = 0·10) for dietary potassium, and 0·89 (95% confidence interval, 0·75-1·04; P, trend = 0·25) for dietary calcium intake. The relative risk of total stroke for men in the highest vs. lowest quintile was 0·74 (95% confidence interval, 0·59-0·93; P, trend = 0·003) for supplemental magnesium, 0·66 (95% confidence interval, 0·50-0·86; P, trend = 0·002) for supplemental potassium, and 1·01 (95% confidence interval, 0·84-1·20; P, trend = 0·83) for supplemental calcium intake. For total intake (dietary and supplemental), the relative risk of total stroke for men in the highest vs. lowest quintile was 0·83 (95% confidence interval, 0·70-0·99; P, trend = 0·04) for magnesium, 0·88 (95% confidence interval, 0·75-4; P, trend = 6) for potassium, and 3 (95% confidence interval, 79-09; P, trend = 84) for calcium. Men in the highest quintile for a combined dietary score of all three cations had a multivariate relative risk of 0·79 (95% confidence interval, 0·67-0·92; P, trend = 0·008) for total stroke, compared with those in the lowest.

CONCLUSIONS

A diet rich in magnesium, potassium, and calcium may contribute to reduced risk of stroke among men. Because of significant collinearity, the independent contribution of each cation is difficult to define.

Oral magnesium supplementation improves glycaemic status in subjects with prediabetes and hypomagnesaemia: A double-blind placebo-controlled randomized trial

AIM

This study evaluated the efficacy of oral magnesium supplementation in the reduction of plasma glucose levels in adults with prediabetes and hypomagnesaemia.

METHODS

A total of 116 men and non-pregnant women, aged 30 to 65 years with hypomagnesaemia and newly diagnosed with prediabetes, were enrolled into a randomized double-blind placebo-controlled trial to receive either 30 mL of MgCl2 5% solution (equivalent to 382 mg of magnesium) or an inert placebo solution once daily for four months. The primary trial endpoint was the efficacy of magnesium supplementation in reducing plasma glucose levels.

RESULTS

At baseline, there were no significant statistical differences in terms of anthropometric and biochemical variables between individuals in the supplement and placebo groups. At the end of follow-up, fasting (86.9 ± 7.9 and 98.3 ± 4.6 mg/dL, respectively; P = 0.004) and post-load glucose (124.7 ± 33.4 and 136.7 ± 23.9 mg/dL, respectively; P = 0.03) levels, HOMA-IR indices (2.85 ± 1.0 and 4.1 ± 2.7, respectively; P = 0.04) and triglycerides (166.4 ± 90.6 and 227.0 ± 89.7, respectively; P = 0.009) were significantly decreased, whereas HDL cholesterol (45.6 ± 10.9 and 46.8 ± 9.2 mg/dL, respectively; P = 0.04) and serum magnesium (1.96 ± 0.27 and 1.60 ± 0.26 mg/dL, respectively; P = 0.005) levels were significantly increased in those taking MgCl2 compared with the controls. A total of 34 (29.4%) people improved their glucose status (50.8% and 7.0% in the magnesium and placebo groups, respectively; P < 0.0005).

CONCLUSION

Our results show that magnesium supplementation reduces plasma glucose levels, and improves the glycaemic status of adults with prediabetes and hypomagnesaemia.

Influence of dietary intake of fish oil, magnesium, and zinc on metabolic parameters among individuals tested for diabetes

OBJECTIVE

The aim of this study was to assess the significance and degree of correlation between the intake of fish oil, magnesium (Mg), and zinc (Zn) and metabolic parameters.

METHODS

Correlation coefficients among nutrient intake and physical and laboratory parameters were determined using Spearman's rho (ρ) test or a multiple regression model among Japanese individuals (male:female, 37:66; median age, 55 y) who completed a semiquantitative food questionnaire and underwent testing for diabetes. Individuals with diabetes were excluded.

RESULTS

Spearman's test revealed several weak but significant correlations between intake of fish oil including ω-3 polyunsaturated fatty acids (PUFAs) and various metabolic parameters. The test showed that Zn intake in women significantly correlated with reduced systolic blood pressure (SBP), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GPT), and homeostasis model assessment-insulin resistance (HOMA-IR). Multivariate analysis revealed that intake of fish oil, eicosapentaenoic acid (EPA), and Zn was significantly associated with increased serum levels of high-density lipoprotein cholesterol (HDL-C; fish oil versus HDL-C, P = 0.0438; 95% confidence interval [CI], 0.0055-0.3724; EPA versus HDL-C, P = 0.0439; 95% CI, 0.0053-0.3724; Zn versus HDL-C, P = 0.0041; 95% CI, 0.0890-0.4609). Multivariate analysis revealed that ω-3 PUFAs were associated with decreased serum ALT levels (P = 0.0240; 95% CI, -5.000 to -0.0367) and that Zn correlated with SBP (P = 0.0239; 95% CI, -0.5149 to -0.0377) in women.

CONCLUSION

Intake of fish oil, Mg, and Zn was associated with some metabolic parameters. Abundant intake of fish oil including ω-3 PUFAs and Zn can exert antiarteriosclerotic effects through increasing serum levels of HDL-C. ω-3 PUFAs can reduce liver inflammation and Zn can reduce SBP in women.

Effects of magnesium depletion on inflammation in chronic disease

PURPOSE OF REVIEW

To update findings supporting the opinion that commonly occurring subclinical magnesium deficiency induced by a low dietary intake is a predisposing factor for chronic inflammatory stress that contributes to the incidence of chronic diseases such as cardiovascular disease and diabetes.

RECENT FINDINGS

Both deficient magnesium intakes (<250 mg/day) and serum magnesium concentrations (≤ 0.75 mmol/l) have been associated with elevated serum C-reactive protein concentration, a widely used indicator of inflammation. Achieving magnesium intakes or serum magnesium concentrations that indicate an adequate magnesium status generally attenuates elevated serum C-reactive protein to concentrations that are not indicative of chronic low-grade inflammation. Individuals that are obese or have chronic diseases for which low-grade inflammation is a risk factor are commonly found to be magnesium-deficient.

SUMMARY

Subclinical magnesium deficiency caused by low dietary intake often occurring in the population is a predisposing factor for chronic inflammatory stress that is conducive for chronic disease. Magnesium deficiency should be considered a nutrient of significant concern for health and well-being.

Dietary magnesium intake and risk of metabolic syndrome: a meta-analysis

AIMS

To estimate quantitatively the association between dietary magnesium intake and risk of metabolic syndrome by combining the relevant published articles using meta-analysis.

METHODS

We reviewed the relevant literature in PubMed and EMBASE published up until August 2013 and obtained additional information through Google or a hand search of the references in relevant articles. A random-effects or fixed-effects model, as appropriate, was used to pool the effect sizes on metabolic syndrome comparing individuals with the highest dietary magnesium intake with those having the lowest intake. The dose-response relationship was assessed for every 100-mg/day increment in magnesium intake and risk of metabolic syndrome.

RESULT

Six cross-sectional studies, including a total of 24 473 individuals and 6311 cases of metabolic syndrome, were identified as eligible for the meta-analysis. A weighted inverse association was found between dietary magnesium intake and the risk of metabolic syndrome (odds ratio 0.69, 95% CI 0.59, 0.81) comparing the highest with the lowest group. For every 100-mg/day increment in magnesium intake, the overall risk of having metabolic syndrome was lowered by 17% (odds ratio 0.83, 95% CI 0. 77, 0.89).

CONCLUSION

Findings from the present meta-analysis suggest that dietary magnesium intake is inversely associated with the prevalence of metabolic syndrome. Further studies, in particular well-designed longitudinal cohort studies and randomized placebo-controlled clinical trials, are warranted to provide solid evidence and to establish causal inference.

Effects of pistachio nut supplementation on blood glucose in patients with type 2 diabetes: a randomized crossover trial

BACKGROUND

Diabetes is a chronic, potentially debilitating, and often fatal disease. Dietary strategies to reduce postprandial glycemia are important in the prevention and treatment of diabetes. Nuts are rich in mono- and polyunsaturated fatty acids, which may reduce hyperglycemia and improve metabolism.

OBJECTIVES

To evaluate the effectiveness of pistachio nut supplementation on glycemic and inflammatory measures in patients with type 2 diabetes.

METHODS

In this double-blind, randomized, placebo-controlled, crossover trial, 48 diabetic patients were equally assigned to groups A and B. Patients in group A received a snack of 25 g pistachio nuts twice a day for 12 weeks and group B received a control meal without nuts. After 12 weeks of intervention, the patients had an 8-week washout. Then the groups were displaced, and group B received the same amount of pistachios for 12 weeks.

RESULTS

With respect to the total change in variables over both phases, there was a marked decrease in HbA1c (-0.4%) and fasting blood glucose (FBG) concentrations (-16 mg/dl) in the pistachio group compared with the control group (p ≤ 0.001 for both). There was no overall significant change in BMI, blood pressure, HOMA-IR, and C-reactive protein (CRP) concentrations. Analysis of the two phases separately showed a decrease in FBG by 14 mg/dl and in HbA1c by 0.45% in the treatment group (A) after 12 weeks, while no significant differences were seen in group B (control group). In the second phase, FBG decreased from 151.36 ± 39.22 to 137.28 ± 28.65 mg/dl (-14 mg/dl) and HbA1c decreased from 7.42 ± 0.97 to 7.15 ± 0.68 mg/dl (-0.28%, p = 0.013 and p = 0.033, respectively) in the pistachio group (B). Pistachio consumption reduced systolic blood pressure (p = 0.007), BMI (p = 0.011), and CRP (p = 0.002) in patients from the treatment groups, but not insulin resistance.

CONCLUSIONS

Dietary consumption of pistachio nuts as a snack has beneficial effects on glycemic control, blood pressure, obesity, and inflammation markers in diabetic patients.

Modulation of glucose metabolism by balanced deep-sea water ameliorates hyperglycemia and pancreatic function in streptozotocin-induced diabetic mice

The aim of this study was to determine the effects of balanced deep-sea water (BDSW) on hyperglycemia and glucose intolerance in streptozotocin (STZ)-induced diabetic mice. BDSW was prepared by mixing DSW mineral extracts and desalinated water to yield a final hardness of 1000–4000 ppm. Male ICR mice were assigned to 6 groups; mice in each group were given tap water (normal and STZ diabetic groups) or STZ with BDSW of varying hardness (0, 1000, 2000, and 4000 ppm) for 4 weeks. The STZ with BDSW group exhibited lowered fasting plasma glucose levels than the STZ-induced diabetic group. Oral glucose tolerance tests showed that BDSW improves impaired glucose tolerance in STZ-induced diabetic mice. Histopathological evaluation of the pancreas showed that BDSW restores the morphology of the pancreatic islets of Langerhans and increases the secretion of insulin in STZ-induced diabetic mice. Quantitative real-time PCR assay revealed that the expression of hepatic genes involved in gluconeogenesis, glucose oxidation, and glycogenolysis was suppressed, while the expression of the genes involved in glucose uptake, β-oxidation, and glucose oxidation in muscle were increased in the STZ with BDSW group. BDSW stimulated PI3-K, AMPK, and mTOR pathway-mediated glucose uptake in C₂C₁₂ myotubes. BDSW increased AMPK phosphorylation in C₂C₁₂ myotubes and improved impaired AMPK phosphorylation in the muscles of STZ-induced diabetic mice. Taken together, these results suggest that BDSW is a potential anti-diabetic agent, owing to its ability to suppress hyperglycemia and improve glucose intolerance by modulating glucose metabolism, recovering pancreatic islets of Langerhans and increasing glucose uptake.

Low serum magnesium levels and diabetic foot ulcers

Objective: Magnesium plays an important role in glucose homeostasis and insulin sensitivity. The aim of this study was to investigate the association between serum magnesium levels and diabetic foot ulcers.

Methods: A total of 147 subjects were included in this study. The participants were divided into three groups, including a study group of 49 patients with diabetes and foot ulcers, a control group of patients with diabetes without foot ulcers and a control group of 49 healthy subjects. Measurements and comparisons were made of the participants’ magnesium levels, HBA1C percentages, serum fasting glucose levels, creatinine levels and serum lipid levels for all groups. MedCalc version 12.0 (MedCalc, Turkey) was used for the statistical analysis.

Results: The groups were similar in terms of age and sex (p=0.116 and 0.897, respectively). The magnesium levels of the patients with diabetes and foot ulcers were lower than those in the patients with diabetes without foot ulcers and the healthy subjects (p<0.001). There was a strong relationship between the serum magnesium levels and the incidence of diabetic foot ulcers (OR 5.9, Cl 95% 2.7-12.6, p<0.001).

Conclusions: A low serum magnesium level is associated with diabetic foot ulcers. Therefore, the magnesium levels should be controlled in patients with diabetes (with or without foot ulcers) and magnesium supplementation can be a complimentary treatment in such cases.