High dietary magnesium intake is associated with low insulin resistance in the Newfoundland population

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

Nutrient patterns in relation to metabolic health status and serum levels of brain-derived neurotrophic factor (BDNF) and adropin in adults

The present study aimed to investigate the association of nutrient patterns (NPs) with metabolic health status and serum levels of brain-derived neurotrophic factor (BDNF) and adropin in Iranian adults. This cross-sectional survey was performed on 527 adults aged 20-60 years in Isfahan, Iran. To evaluate dietary intake, a validated 168-item semi-quantitative food frequency questionnaire (FFQ) was used. Participants were categorized as metabolically healthy (MH) and metabolically unhealthy (MU) according to their glycemic and lipid profile, insulin resistance (IR), and inflammation status. An overnight fasting blood sample was collected from each participant and serum levels of BDNF and adropin were assessed. A total of 42.50% of participants were recognized as MU. Three NPs were recognized by factor analysis that labeled as "high animal protein" (NP1), "high vegetable" (NP2), and "high carbohydrate" (NP3) patterns. Moderate adherence to NP2 was related to a lower risk of MU (ORT2 vs. T1 = 0.38, 95% CI: 0.18-0.76). Moreover, high adherence of NP2 (T3 vs. T1) was inversely associated with hypertriglyceridemia (OR = 0.27, 95% CI: 0.11-0.65; P-trend < 0.001) and high hs-CRP values (OR = 0.29, 95% CI: 0.09-1.00; P-trend = 0.03). No significant association was observed between adherence of NP1 and NP3 with MU in crude and adjusted models. However, negative associations were found between moderate adherence to NP3 and insulin resistance (IR) (OR = 0.23, 95% CI: 0.06-0.91) as well as high adherence to NP1 and hypertension (OR = 0.23, 95% CI: 0.09-0.61; P-trend < 0.001). NPs were not associated with serum BDNF and adropin values.

Potassium Magnesium Citrate Is Superior to Potassium Chloride in Reversing Metabolic Side Effects of Chlorthalidone

BACKGROUND

Thiazide diuretics (TD) are the first-line treatment of hypertension because of its consistent benefit in lowering blood pressure and cardiovascular risk. TD is also known to cause an excess risk of diabetes, which may limit long-term use. Although potassium (K) depletion was thought to be the main mechanism of TD-induced hyperglycemia, TD also triggers magnesium (Mg) depletion. However, the role of Mg supplementation in modulating metabolic side effects of TD has not been investigated. Therefore, we aim to determine the effect of potassium magnesium citrate (KMgCit) on fasting plasma glucose and liver fat by magnetic resonance imaging during TD therapy.

METHODS

Accordingly, we conducted a double-blinded RCT in 60 nondiabetic hypertension patients to compare the effects of KCl versus KMgCit during chlorthalidone treatment. Each patient received chlorthalidone alone for 3 weeks before randomization. Primary end point was the change in fasting plasma glucose after 16 weeks of KCl or KMgCit supplementation from chlorthalidone alone.

RESULTS

The mean age of subjects was 59±11 years (30% Black participants). Chlorthalidone alone induced a significant rise in fasting plasma glucose, and a significant fall in serum K, serum Mg, and 24-hour urinary citrate excretion (all P<0.05). KMgCit attenuated the rise in fasting plasma glucose by 7.9 mg/dL versus KCl (P<0.05), which was not observed with KCl. There were no significant differences in liver fat between the 2 groups.

CONCLUSIONS

KMgCit is superior to KCl, the common form of K supplement used in clinical practice, in preventing TD-induced hyperglycemia. This action may improve tolerability and cardiovascular safety in patients with hypertension treated with this drug class.

Relationships between serum and dietary magnesium, calcium, and metabolic parameters in women with type 2 diabetes mellitus

BACKGROUND & AIMS

Magnesium and calcium are essential minerals in several enzymatic activities that modulate essential biological functions. Hypomagnesemia occurs in patients with type 2 diabetes mellitus (T2DM), especially those with poor metabolic control. Dietary magnesium and calcium intake play a protective role in the development of T2DM. This research aimed to investigate the association of dietary and serum magnesium and calcium with metabolic control parameters in diabetic women.

METHODS

This case-control study was conducted on 80 women, including 40 patients diagnosed with T2DM and 40 healthy controls aged 35-60 years. Some anthropometric measurements of the individuals were taken, and their body mass index was calculated. In addition, some biochemical parameters, serum magnesium, and calcium were analyzed. A validated 96-item quantitative food frequency questionnaire was used to obtain dietary magnesium and calcium intake data.

RESULTS

Serum magnesium levels were lower in subjects with diabetes than in controls, and there was a similar incidence of hypomagnesemia in T2DM patients and controls, but not statistically significant (p > 0.05). In T2DM patients, there was a statistically significant inverse association between HbA1c and serum magnesium (p < 0.05). Dietary magnesium intake was inversely associated with HOMA-IR scores (p < 0.05) but had a positive association with serum magnesium levels in patients with T2DM (p < 0.05). There were no significant differences in the calcium/magnesium ratio between T2DM patients and healthy controls (p > 0.05). In a multiple linear regression analysis, dietary magnesium intake and HbA1c were found to be significantly related to altered serum magnesium in T2DM patients.

CONCLUSION

The present findings suggest that lower serum magnesium levels were associated with higher HbA1c levels in subjects with T2DM. Increased dietary magnesium intake in T2DM may enhance HOMA-IR scores and serum magnesium levels.

Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences

PURPOSE

To examine the association between dietary magnesium (Mg) intake and brain volumes and white matter lesions (WMLs) in middle to early old age.

METHODS

Participants (aged 40-73 years) from UK Biobank (n = 6001) were included and stratified by sex. Dietary Mg was measured using an online computerised 24 h recall questionnaire to estimate daily Mg intake. Latent class analysis and hierarchical linear regression models were performed to investigate the association between baseline dietary Mg, Mg trajectories, and brain volumes and WMLs. Associations between baseline Mg, and baseline blood pressure (BP) measures, and baseline Mg, Mg trajectories and BP changes (between baseline and wave 2) were also investigated to assess whether BP mediates the link between Mg intake and brain health. All analyses controlled for health and socio-demographic covariates. Possible interactions between menopausal status and Mg trajectories in predicting brain volumes and WMLs were also investigated.

RESULTS

On average, higher baseline dietary Mg intake was associated with larger brain volumes (gray matter [GM]: 0.001% [SE = 0.0003]; left hippocampus [LHC]: 0.0013% [SE = 0.0006]; and right hippocampus [RHC]: 0.0023% [SE = 0.0006]) in both men and women. Latent class analysis of Mg intake revealed three classes: "high-decreasing" (men = 3.2%, women = 1.9%), "low-increasing" (men = 1.09%, women = 1.62%), and "stable normal" (men = 95.71%, women = 96.51%). In women, only the "high-decreasing" trajectory was significantly associated with larger brain volumes (GM: 1.17%, [SE = 0.58]; and RHC: 2.79% [SE = 1.11]) compared to the "normal-stable", the "low-increasing" trajectory was associated with smaller brain volumes (GM: - 1.67%, [SE = 0.30]; white matter [WM]: - 0.85% [SE = 0.42]; LHC: - 2.43% [SE = 0.59]; and RHC: - 1.50% [SE = 0.57]) and larger WMLs (1.6% [SE = 0.53]). Associations between Mg and BP measures were mostly non-significant. Furthermore, the observed neuroprotective effect of higher dietary Mg intake in the "high-decreasing" trajectory appears to be greater in post-menopausal than pre-menopausal women.

CONCLUSIONS

Higher dietary Mg intake is related to better brain health in the general population, and particularly in women.

Magnesium and Fracture Risk in the General Population and Patients Receiving Dialysis: A Narrative Review

Purpose of Review

Magnesium is an essential mineral for bone metabolism, but little is known about how magnesium intake alters fracture risk. We conducted a narrative review to better understand how magnesium intake, through supplementation, diet, or altering the concentration of dialysate magnesium, affects mineral bone disease and the risk of fracture in individuals across the spectrum of kidney disease.

Sources of Information

Peer-reviewed clinical trials and observational studies.

Methods

We searched for relevant articles in MEDLINE and EMBASE databases. The methodologic quality of clinical trials was assessed using a modified version of the Downs and Black criteria checklist.

Key Findings

The role of magnesium intake in fracture prevention is unclear in both the general population and in patients receiving maintenance dialysis. In those with normal kidney function, 2 meta-analyses showed higher bone mineral density in those with higher dietary magnesium, whereas 1 systematic review showed no effect on fracture risk. In patients receiving maintenance hemodialysis or peritoneal dialysis, a higher concentration of dialysate magnesium is associated with a lower concentration of parathyroid hormone, but little is known about other bone-related outcomes. In 2 observational studies of patients receiving hemodialysis, a higher concentration of serum magnesium was associated with a lower risk of hip fracture.

Limitations

This narrative review included only articles written in English. Observed effects of magnesium intake in the general population may not be applicable to those with chronic kidney disease particularly in those receiving dialysis.

Beneficial effects of adding magnesium to desalinated drinking water on metabolic and insulin resistance parameters among patients with type 2 diabetes mellitus: a randomized controlled clinical trial

There is evidence that increasing the consumption of water containing magnesium can improve glucose metabolism and insulin resistance in patients with type 2 diabetes mellitus (T2DM). This trial was undertaken with the objective of evaluating the effect of adding different concentrations of magnesium chloride to the desalinated drinking water on the glycemic, metabolic, and insulin resistance parameters among patients with T2DM. A randomized cross-sectional controlled clinical trial was conducted to evaluate the effects of adding magnesium chloride supplement to desalinated drinking water consumed by patients with T2DM on the glycemic and metabolic parameters and indicators of insulin sensitivity. The total number of patients with T2DM who successfully completed the trial is 102. Patients were randomly allocated into three groups: the first group received bottled water without added magnesium (0 mg/L) (Group A, n = 37); the second group received bottled water with a low level of magnesium (20 mg/L) (Group B, n = 33); and the third group received drinking water with a high level of magnesium (50 mg/L) (Group C, n = 32). The daily consumption of elemental magnesium for a period of 3 months resulted in significant improvement in HbA1C (8.0 vs 8.2%, p = 0.04), insulin level (7.5 vs 9.9 μIU/mL, p = 0.03), and homeostasis model assessment-estimated insulin resistance (HOMA.IR) (2.5 vs 2.9, p = 0.002) in group C. However, there was no significant improvement in fasting blood glucose (FBS) level or lipid profile. The results of this study suggest that oral magnesium supplementation at the given dose of 50 mg/L daily added to drinking water could improve long-term glycemic control indicators and reduce insulin resistance in patients with T2DM.

Association of Serum Magnesium with Insulin Indices in Patients with Type 2 Diabetes Mellitus

Introduction: Magnesium has a direct impact on glucose metabolism since it is a cofactor for numerous energy-metabolizing enzymes. Hypomagnesemia has been linked to poor glycemic control and a range of diabetes-related long-term complications. This study aimed to assess the association between blood magnesium levels and insulin sensitivity indices in patients with type 2 diabetes mellitus (T2DM). Material and methods:Two hundred newly diagnosed T2DM patients aged over 40 years were recruited after excluding those with a history of heart failure, kidney illness, liver disease, hypothyroidism, ascites, pregnancy, tumors, and complications such as diabetic ketoacidosis. Fasting glucose, serum magnesium, serum insulin, serum urea and creatinine were measured. Patients were divided into two groups based on their serum magnesium levels. Results:There were no age or sex differences between the subjects of the two groups. Participants in the group with low magnesium had significantly high fasting blood sugar (FBS), postprandial blood sugar (PPBS), glycated hemoglobin (HbA1c), serum insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR) (P < 0.001). The multivariable logistic regression analysis showed significant associations with PPBS [odds ratio (OR) 0.98 (95% CI 0.97-0.99)], HbA1c [OR 0.05 (95% CI=0.005-0.55)] and creatinine [OR 0.004 (95% CI=0.00-0.074)]. Correlation statistics showed a negative correlation between magnesium and PPBS (r =-0.204), HOMA-IR (r = -0.819) and creatinine (r = -0.151). Conclusion:Serum magnesium levels have a negative correlation with FBS and PPBS, as well as HOMA-IR. It may well be essential to include serum magnesium level as a regular assessment in patients with diabetes mellitus.

Magnesium supplementation and insulin resistance in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a multifactorial disease affecting the immune system and many tissues in the body. This study aimed to evaluate the effect of magnesium supplementation on insulin resistance and fasting blood sugar (FBS) of patients with RA. In this prospective uncontrolled before-after study, RA patients referring to Rheumatology clinics of Qom City from January 2020 to January 2021 were evaluated. First, the patients received the routine rheumatoid arthritis treatment including 5 mg Prednisolone and 200mg Hydroxychloroquine daily for 6 months and FBS and insulin levels were measured after. Then, they received the routine arthritis rheumatoid treatment in addition to 300 mg/day oral Magnesium sulfate for 6 months and then, FBS and insulin levels were measured. The Homeostasis Model Assessment of insulin resistance (HOMA-IR) was used for determining insulin resistance. Thirty five patients with RA and the mean age of 49.83±2.58 years were enrolled. Twenty eight cases (80%) were female and 7 cases (20%) were male. The mean HOMA-IR before and after consumption of oral magnesium were 3.04±0.29 and 2.43±0.19, respectively. Statistically significant differences were found between FBS, insulin and HOMA-IR before and after consumption of oral magnesium (p<0.05). Our data suggested that magnesium supplementation reduces FBS, insulin and HOMA-IR in patients with rheumatoid arthritis. Thus, magnesium supplements may be an alternative method for prevention of type 2 diabetes in RA patients.

Relationship Between Serum Magnesium Level and Insulin Resistance in Turkey Non-obese Adult Population

The homeostasis model assessment of insulin resistance (HOMA-IR) is widely used in clinical practice to estimate insulin resistance. In particular, magnesium (Mg) is an extensively studied mineral that has been shown to function in the management of hyperglycemia and insulin resistance (IR) action. The pathophysiology of IR in non-obese patients has not been clearly demonstrated. From this point of view, we aimed to investigate the relationship between serum Mg level and IR in non-obese patients. We analyzed 957 patients who are not obese and estimated glomerular filtration rate (e-GFR) ≥ 60 mL/min/1.73 m². Patients were divided into two groups, with and without IR. The results of the IR detected group (HOMA-IR ≥ 2.5, n = 544) and the IR undetected group (HOMA-IR < 2.5, n = 413) were compared. The median Mg value of the patients was 1.76 [0.21] mg/dL. A statistically significant difference was observed between the two groups regarding serum Mg levels (p = 0.043). A negative correlation was found between the HOMA-IR index and serum Mg levels among patients (r =  - 0.064, p = 0.049). Multivariable logistic regression analysis revealed that serum Mg level (p = 0.039, odds ratio [OR] = 0.770[95%CI: [0.917-0.989]) was independent risk factors for IR. HOMA-IR increases as the Mg level decreases in advanced ages without obesity, especially in men with low e-GFR.

Associations of multiple plasma metals with the risk of metabolic syndrome: A cross-sectional study in the mid-aged and older population of China

BACKGROUND

Metal exposures have been reported to be related to the progress of metabolic syndrome (MetS), however, the currents results were still controversial, and the evidence about the effect of multi-metal exposure on MetS were limited. In this study, we intended to evaluate the relationships between metal mixture exposure and the prevalence of MetS in a mid-aged and older population of China.

METHODS

The plasma levels of 13 metals (aluminum, magnesium, calcium, iron, manganese, cobalt, copper, arsenic, zinc, selenium, cadmium, molybdenum and thallium) were detected by inductively coupled plasma mass spectrometry (ICP-MS) in 1277 adults recruited from the Eighth Affiliated Hospital of Sun Yat-Sen University (Shenzhen, China). Logistic regression, the adaptive least absolute shrinkage and selectionator operator (LASSO) penalized regression analysis and restricted cubic spline (RCS) analysis were used to explore the associations and dose-response relationships of plasma metals with MetS. To evaluate the cumulative effect of metals, the Bayesian Kernel Machine Regression (BKMR) model was applied.

RESULTS

The concentrations of magnesium and molybdenum were lower in the MetS group (p < 0.05). In the single-metal model, the adjusted ORs (95%CI) in the highest quartiles were 0.44 (0.35, 0.76) for magnesium and 0.30 (0.17, 0.51) for molybdenum compared with the lowest quartile. The negative associations and dose-dependent relationships of magnesium and molybdenum with MetS were further validated by the stepwise model, adaptive LASSO penalized regression and RCS analysis. The BKMR models showed that the metal mixture were associated with decreased MetS when the chemical mixtures were≥ 25th percentile compared to their medians, and Mg, Mo were the major contributors to the combined effect. Moreover, concentrations of magnesium were significantly related to blood glucose, and molybdenum was related with BMI, blood glucose and blood pressure.

CONCLUSIONS

Elevated levels of plasma magnesium and molybdenum were associated with decreased prevalence of MetS. Further investigations in larger perspective cohorts are needed to confirm our findings.

Personalized Nutrition as a Key Contributor to Improving Radiation Response in Breast Cancer

Understanding metabolic and immune regulation inherent to patient populations is key to improving the radiation response for our patients. To date, radiation therapy regimens are prescribed based on tumor type and stage. Patient populations who are noted to have a poor response to radiation such as those of African American descent, those who have obesity or metabolic syndrome, or senior adult oncology patients, should be considered for concurrent therapies with radiation that will improve response. Here, we explore these populations of breast cancer patients, who frequently display radiation resistance and increased mortality rates, and identify the molecular underpinnings that are, in part, responsible for the radiation response and that result in an immune-suppressive tumor microenvironment. The resulting immune phenotype is discussed to understand how antitumor immunity could be improved. Correcting nutrient deficiencies observed in these populations should be considered as a means to improve the therapeutic index of radiation therapy.

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.

Associations Between Serum Magnesium Concentrations and Polycystic Ovary Syndrome Status: a Systematic Review and Meta-analysis

Magnesium (Mg) is the second most frequent intracellular cation in humans with a critical role in insulin metabolism and glucoregulation. Women with polycystic ovary syndrome (PCOS) often present with insulin resistance and impaired glucoregulatory status; however, their Mg status remains unclear. Therefore, we aimed to conduct a systematic review and meta-analysis to evaluate serum Mg concentration in women with PCOS and compare it with that of controls without PCOS. Online databases of PubMed, Scopus, Cochrane Library, and ISI Web of Science were searched for studies evaluating the relationship between Mg concentrations and PCOS status until October 2019. Pooled weighted mean differences (WMDs) of serum Mg levels were calculated using random effects models. A total of eight studies (10 arms; n = 2026 women) were included. Pooled effect sizes, expressed as WMD and 95% CI, revealed decreased serum Mg concentrations in women with PCOS compared with controls (- 0.09 (- 0.17, - 0.02) mmol/L; P = 0.01). However, significant heterogeneity was detected across the studies (I ² = 98.0%, P < 0.001). Despite the classification of studies based on baseline BMI classes, we did not detect the potential source of the observed heterogeneity. Subgroup analysis showed that overweight and obese women (BMI ≥ 25 kg/m², 0.07 mmol/L (- 0.14, - 0.01); P = 0.02) with PCOS had lower magnesium concentrations than normal women (BMI < 25 kg/m², - 0.11 (- 0.25, 0.04) mmol/L; P = 0.14) compared with the control group. Serum Mg concentrations appear to be declined in overweight or obese women with PCOS, which may warrant screening and management of Mg status in this clinical population. High-quality studies are needed to elucidate the relationship between Mg concentrations and the development of PCOS.

Calcium to magnesium intake ratio and non-alcoholic fatty liver disease development: a case-control study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Adoption of sedentary life style and westernized diet are shown to be associated with development of NAFLD. Since previous studies suggested that calcium (Ca) to magnesium (Mg) ratio intake is associated with some chronic diseases including dyslipidemia and insulin resistance, we designed this study to find any possible association between this ratio and NAFLD development.

METHODS

The NAFLD was diagnosed using Fibroscan according to a CAP cut-off value of 263 dB/m. Dietary intakes of one hundred and ninety-six patients with incident NAFLD diagnosis, and eight hundred and three controls without NAFLD were assessed using a valid food frequency questionnaire (FFQ). Dietary nutrients were calculated using Nutritionist IV software.

RESULTS

Age of the study population (57 % female) was 43.2 ± 14.1 years. In addition, energy-adjusted daily calcium to magnesium intake ratio was 2.34 ± 0.57 and 2.73 ± 0.69 for control and case groups, respectively. In the multivariable-adjusted model, after adjustment for potential confounding variables; including, age, gender, BMI, alcohol consumption, smoking, diabetes, physical activity, energy, dietary fiber, carbohydrate, fat, and protein intakes, participants in the third (Q3) and fourth (Q4) quartile of Ca/Mg ratio intake had a greater development of incidental NAFLD compared to the lowest quartile (Q1) [(OR = 2.86; 95 % CI: 1.20-6.81), (P-value = 0.017) and (OR = 5.97; 95 % CI: 2.54-14.01), (P-value < 0.001) for Q3 and Q4 compared to the Q1, respectively]. Moreover, energy-adjusted Ca to Mg intake ratio was positively correlated with plasma level of ALT (r = 0.18; P = 0.01); contrarily, it had no correlation with plasma levels of AST.

CONCLUSIONS

The current study revealed that higher dietary Ca to Mg intake ratio is associated with a greater development of NAFLD. Further interventional studies are needed to confirm the causal relationship of the Ca/Mg ratio intake and development of NAFLD.

Magnesium intake, insulin resistance and markers of endothelial function among women

OBJECTIVE

We investigated the association of dietary Mg intake with insulin resistance and markers of endothelial function among Iranian women.

DESIGN

A cross-sectional study.

SETTING

Usual dietary intakes were assessed using a validated FFQ. Dietary Mg intake was calculated by summing up the amount of Mg in all foods. A fasting blood sample was taken to measure serum concentrations of glycemic indices (fasting plasma glucose and insulin) and endothelial function markers (E-selectin, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1). Insulin resistance and sensitivity were estimated using the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR), Homeostasis Model Assessment β-cell function (HOMA-β) and quantitative insulin sensitivity check index (QUICKI).

PARTICIPANTS

Iranian female nurses (n 345) selected by a multistage cluster random sampling method.

RESULTS

The Mg intake across energy-adjusted quartiles was 205 (se 7), 221·4 (se 8), 254·3 (se 7) and 355·2 (se 9) mg/d, respectively. After adjustments for potential confounders, QUICKI level was significantly different across quartiles of Mg intake (Q1: 0·34 (se 0·02), Q2: 0·36 (se 0·01), Q3: 0·40 (se 0·01), and Q4: 0·39 (se 0·02), P = 0·02); however, this association disappeared after considering markers of endothelial function, indicating that this relation might be mediated through endothelial dysfunction. After controlling for all potential confounders, Mg intake was inversely, but not significantly, associated with serum concentrations of sICAM (Q1: 239 (se 17), Q2: 214 (se 12), Q3: 196 (se 12), and Q4: 195 (se 17), P = 0·29). There was no other significant association between dietary Mg intake and other indicators of glucose homoeostasis or endothelial markers.

CONCLUSIONS

Higher dietary Mg intake was associated with better insulin sensitivity in Iranian females. This linkage was mediated through reduced endothelial dysfunction.

Dietary magnesium intake in relation to body mass index and glycemic indices in middle school students from the HEALTHY Study

BACKGROUND

Data on dietary magnesium intake on the risk of type 2 diabetes mellitus (T2DM) among children and adolescents is limited.

AIM

We examined whether dietary magnesium intake was related to body mass index (BMI) percentile, and glycemic indices at baseline and at end of the HEALTHY Study for both intervention and control schools. The HEALTHY Study was a multi-component, school-based intervention, to prevent T2DM in children and adolescents from 6th to 8th grades.

METHODS

A secondary data analyses of 2181 ethnically diverse students with completed dietary records, BMI percentile, and plasma insulin and glucose concentrations at baseline (6th grade) and end of study (8th grade) were included from the HEALTHY Study. Dietary magnesium intake was self-reported using the Block Kids Food Frequency Questionnaire. A hierarchical multiple regression model was used to determine the relationships between dietary magnesium intake, BMI percentile, and glycemic indices at baseline and end of the HEALTHY Study, adjusting for magnesium intake from supplements, total energy intake, and fitness level.

RESULTS

Dietary magnesium intake was related to BMI percentile at baseline and at end of the HEATHY Study (β = -0.05, 95% CI = -0.02 to 0, p = 0.04; β = -0.06, 95% CI = -0.02 to -0.003, p = 0.004); R ² [regression coefficient effect size] = 0.03; R ² = 0.06). Dietary magnesium intake was not related to plasma insulin and glucose concentrations at baseline and end of the HEALTHY Study.

CONCLUSION

Dietary magnesium intake was inversely related to BMI percentile among middle school students from the HEALTHY Study. Research is required to evaluate the dose-response relationship between fruit and vegetable consumption (good sources of magnesium) and risk of T2DM in children and adolescents. This relationship also needs to be explored among different BMI categories.

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.

The Association between Excess Body Mass and Disturbances in Somatic Mineral Levels

BACKGROUND

Obesity and excess body weight are significant epidemiological issues, not only because they are costly to treat, but also because they are among the leading causes of death worldwide. In 2016, an estimated 40% of the global population was overweight, reflecting the importance of the issue. Obesity is linked to metabolism malfunction and concomitantly with altered mineral levels in the body. In this paper, we review alterations in somatic levels of iron, calcium, magnesium, copper, iodine, chromium, selenium, and zinc in relation to excess body mass.

METHODOLOGY

An electronic literature search was performed using PubMed. Our search covered original English research articles published over the past five years, culminating in 63 papers included for study.

RESULTS

The reviewed papers presented correlation between obesity and hypomagnesemia and hypozincemia. They also indicated that patients with excess body mass present increased body copper levels. Studies have similarly indicated that obesity appears to be associated with lower selenium levels in both blood and urine, which may be correlated with the decline and weakening of defenses against oxidative stress. It has been found that decreased level of chromium is connected with metabolic syndrome. Chromium supplementation influences body mass, but the effect of the supplementation depends on the chemical form of the chromium. It is hypothesized that obesity poses a risk of iodine deficiency and iodine absorption may be disrupted by increased fat intake in obese women. A range of studies have suggested that obesity is correlated with iron deficiency. On the other hand, some reports have indicated that excess body mass may coexist with iron excess. The relation between obesity and body iron level requires further investigation. Calcium signaling seems to be disturbed in obesity, due to the increased production of reactive oxygen species and low level of fast troponin isoform responsible for mediating calcium sensitivity of muscle relaxation. Correlation between excess body mass and calcium levels needs further research.

CONCLUSIONS

Excess body mass is associated with alterations in mineral levels in the body, in particular hypomagnesemia and decreased selenium (Se) and zinc (Zn) levels. Chromium (Cr) deficiency is associated with metabolic syndrome. Obese patients are at risk of iodine deficiency. Excess body mass is associated with elevated levels of copper (Cu). Data on the association between obesity and iron (Fe) levels are contradictory. Obesity coexists with disturbed calcium (Ca) signaling pathways. The association between obesity and body Ca levels has not been investigated in detail.

Cube natural sea salt ameliorates obesity in high fat diet-induced obese mice and 3T3-L1 adipocytes

Sodium is an essential component of the human body, with known influences on obesity. This paper reports the effect of cube natural sea salt (CNS) on the reduction of obesity in high fat diet-induced obese C57BL/6 mice and 3T3-L1 adipocytes, by ameliorating the obesity parameters and obesity-related gene mechanisms. The suppression of high fat diet-induced obesity and differentiated 3T3-L1 adipocytes by sea salt depends on the manufacturing process and mineral content. The manufacturing method using only new sea water (Cube natural sea salt) decreases the magnesium (Mg) and sulfur (S) content in the salt with different crystallization and morphologies, compared to the general manufacturing method (Generally manufactured sea salt, GS). Mg in salt is known to considerably affect obesity; an appropriate concentration of magnesium chloride (MgCl₂) reduces lipid accumulation significantly and regulates the lipogenesis and liver enzyme activity. Our results indicate that sea salt contains an appropriate level of Mg as compared to table salt (purified salt, NaCl), and is important for regulating obesity, as observed in the in vivo and in vitro anti-obesity effects of CNS. The Mg content and mineral ratio of sea salt are important factors that ameliorate the lipid metabolism and liver enzyme activity in high fat diet induced obesity, and contents of Mg in sea salt can be altered by modifying the manufacturing process.

Dietary Minerals Measurement in Normal Versus Obese Native American Adolescents

Obesity remains one of the five leading global risks for mortality in both developed and developing countries. Changes in dietary approaches have recently emerged as an approach to combat and prevent the high prevalence of obesity, specifically for minority groups having higher obesity rates. However, little research has been conducted on specific obesity rates in the Native American adolescent population and its' correlation to micronutrient intake. Our study chose a specific minority population of adolescents in order to contribute more academic research on obesity rates and micronutrient intake on Native American adolescents. Data was compiled using the Harvard School of Public Health Youth/Adolescent Questionnaire, which allowed significant results to be found among normal weight, overweight, and obese, male and female adolescents. This study used anthropometric measurements and dietary assessments to obtain baseline measurements and further determine the cause of the prevalence of obesity within Native American adolescent population. The majority of minerals featured significant results among various populations, more specifically among normal weight and obese males. Our finding indicates a relationship between a higher mineral intake and lower body weight in the male adolescent population. The data revealed an innovative correlation between micronutrient intake and obesity prevalence in Native American adolescents, which may provide a potential intervention to further prevent or combat obesity rates.

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.

Pentoxifylline with metformin treatment improves biochemical parameters in patients with nonalcoholic steatohepatitis

Background

The progression of the nonalcoholic fatty liver disease to nonalcoholic steatohepatitis (NASH) is multifactorial, and there is still a lack of approved medications for its treatment. The study aimed to evaluate the impact of combined treatment with Pentoxifylline and Metformin on biochemical parameters in patients with Nash. Setting: Outpatient hepatology clinic.

Methods

A prospective trial was conducted. The first cohort included patients with biopsy-proven Nash, while the second cohort consisted of patients with biopsy-confirmed NAFLD. Blood tests were checked at baseline and every three months. Pentoxifylline at a dosage of 400 mg t.i.d. and Metformin at the dosage of 500 mg t.i.d. were introduced for six months in Nash group. The impact of the treatment was assessed based on biochemical results after combined treatment with low-cost medications.

Results

All 33 Nash patients completed 24 weeks of treatment. We observed significant improvement (p<0.05) of median values after treatment for the following parameters: serum uric acid levels decreased by 51.0 mmol/L, calcium decreased for 0.27 mmoL/L, magnesium showed an increase of 0.11 mmoL/L. Insulin resistance improved as a reduction of HOMA - IR by 1.3 was detected. A significant decrease of median in liver enzymes, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyltransferase by 24.0 U/L, 9.1 U/L, 10.8 U/L respectively, was noted.

Conclusions

Pentoxifylline and Metformin may provide possible treatment option in Nash. Some new potential benefit of the therapy in improving liver function whilst decreasing cardiovascular risk was perceived.

Higher serum choline and betaine levels are associated with better body composition in male but not female population

Background

Animal studies proved that choline and betaine have beneficial effect on reducing body fat. However, evidence in humans is scarce. We aim to investigate the association between serum choline and betaine levels with body composition in general population.

Methods

This is an observational cross-sectional study performed in 1081 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study. Serum choline and betaine levels were measured based on liquid chromatography coupled with tandem mass spectrometry technology. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.

Results

Significantly inverse correlations were found between serum betaine levels and all obesity measurements in males (r ranged from -0.12 to -0.23, and p<0.01 for all) but not in females. Serum choline was negatively associated with total percent body fat (%BF), percent trunk fat (%TF), weight, body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (r ranged from -0.11 to -0.19, and p<0.05 for all) in males and positively associated with weight, BMI and WC (r ranged from 0.09 to 0.10, and p<0.05 for all) in females. The negative associations between serum choline and betaine levels with obesity in males were more profound in those not on any medication than those taking medications. Moreover, obese males had the lowest serum choline and betaine levels, followed by overweight males, and normal weight males having the highest serum choline and betaine levels, especially in those not taking medications (p<0.05). Likewise, subjects with the highest serum levels of both had the lowest obesity indexes, especially those not taking medications.

Conclusions

Higher serum choline and betaine levels were associated with a more favorable body composition (lower body fat and higher lean body mass) in males and the favorable association was more pronounced in non-medication users.

Association of dietary and serum magnesium with glucose metabolism markers: The Furukawa Nutrition and Health Study

BACKGROUND & AIMS

Magnesium may play an important role in cardio-metabolic abnormalities, including type 2 diabetes, but epidemiological evidence linking magnesium status to glucose metabolism is limited among Asians. We cross-sectionally examined the association of dietary and serum magnesium with markers of glucose metabolism among Japanese subjects.

METHODS

Subjects were 1796 workers, aged 18-78 years, who participated in a health survey. Dietary magnesium intake was assessed with a validated brief diet history questionnaire. Serum magnesium concentrations were measured using an enzymatic method. Multivariable linear regression models were used to estimate means of fasting insulin, fasting plasma glucose, homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β), and glycated hemoglobin (HbA1c), with adjustments made for potential confounding variables.

RESULTS

Dietary magnesium was inversely associated with HOMA-IR (P_trend = 0.01). Multivariable-adjusted means (95% confidence intervals) of HOMA-IR for the lowest to highest quartiles of dietary magnesium were 0.94 (0.89-0.99), 0.92 (0.88-0.97), 0.88 (0.83-0.92), and 0.86 (0.81-0.90). Serum magnesium concentrations were also inversely associated with HOMA-IR (P_trend = 0.04) and HbA1c (P_trend <0.01). Multivariable-adjusted means (95% confidence intervals) for the lowest to highest quartiles of serum magnesium were 0.94 (0.90-0.98), 0.87 (0.83-0.91), 0.90 (0.85-0.95), and 0.86 (0.81-0.92) for HOMA-IR and 5.41 (5.36-5.45), 5.33 (5.28-5.37), 5.30 (5.25-5.36), and 5.28 (5.22-5.35) for HbA1c. Excluding subjects with diabetes did not materially change the association between dietary magnesium and HOMA-IR (P_trend <0.01), while it attenuated the association of serum magnesium with HOMA-IR (P_trend = 0.27) and HbA1c (P_trend = 0.15).

CONCLUSIONS

The present findings suggest that lower dietary magnesium, but not serum magnesium, is associated with IR in apparently healthy adults.

Association of Plasma Magnesium with Prediabetes and Type 2 Diabetes Mellitus in Adults

Our study aimed to assess the associations of plasma magnesium with prediabetes and type 2 diabetes (T2D) among Chinese adults. We conducted a case-control analysis of 4447 participants: 867 newly diagnosed prediabetes patients, 1475 newly diagnosed T2D patients and 2105 normal glucose tolerance (NGT) individuals. In a subsample of 599 apparently healthy individuals, we measured plasma hs-CRP levels to examine their relation to plasma magnesium. Plasma magnesium and hs-CRP were measured by inductively coupled plasma mass spectrometry and an enzyme-linked immunosorbent assay, respectively. Plasma magnesium decreased from NGT to prediabetes to T2D, and was inversely associated with prediabetes and T2D. After adjustment for potential confounding factors, the ORs from the lowest to highest quartiles of plasma magnesium were 1, 0.57 (95%CI, 0.44–0.74), 0.49 (0.37–0.65) and 0.51 (0.37–0.70) for prediabetes, and 1, 0.26 (0.20–0.33), 0.15 (0.12–0.20) and 0.15 (0.11–0.20) for T2D. Consistently, plasma magnesium was inversely correlated with plasma hs-CRP in our subsample analysis; the geometric mean hs-CRP concentration for ascending quartiles of plasma magnesium were 1.29 (1.06–1.57), 1.16 (0.95–1.41), 1.00 (0.81–1.22), and 0.71 (0.58–0.88) mg/l. Plasma magnesium was independently and inversely associated with prediabetes and T2D in Chinese adults.

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.

Serum magnesium concentration is independently associated with non-alcoholic fatty liver and non-alcoholic steatohepatitis

Background

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) has not been well recognized yet.

Objective

This study aimed to investigate the association between serum magnesium concentration and NAFLD.

Methods

Study participants were healthy individuals who had undergone liver biopsies between January 2012 and August 2015 as a routine pre-transplant check-up before living donor liver transplantation. Liver biopsy specimens were evaluated by an expert pathologist regarding presence of hepatic steatosis and steatohepatitis. Serum magnesium concentration was measured and compared in those with normal liver biopsy and those with steatosis and steatohepatitis.

Results

A total of 226 individuals were included. Eighty-two individuals (36.2%) had hepatic steatosis and 22 (9.7%) individuals had steatohepatitis and steatosis in their liver histology. Lower serum magnesium concentration was independently associated with hepatic steatosis (OR: 0.059; 95% CI: 0.011-0.325, p = 0.001). Serum magnesium concentration was independently associated with steatohepatitis compared to those without steatohepatitis (1.80 ± 0.48 mg/dl and 2.18 ± 0.31 mg/dl) (OR: 0.11; 95% CI: 0.02-0.41, p = 0.001). Serum magnesium concentration was significantly lower in individuals with steatohepatitis (1.80 ± 0.48 mg/dl) compared to individuals without steatosis (2.23 ± 0.31 mg/dl, p < 0.001) and individuals with only steatosis (2.07 ± 0.29 mg/dl, p = 0.017).

Conclusion

Serum magnesium concentration is independently associated with hepatic steatosis and steatohepatitis in our study population.

High dietary selenium intake is associated with less insulin resistance in the Newfoundland population

As an essential nutrient, Selenium (Se) is involved in many metabolic activities including mimicking insulin function. Data on Se in various biological samples and insulin resistance are contradictory, moreover there is no large study available regarding the relationship of dietary Se intake with insulin resistance in the general population. To investigate the association between dietary Se intake and variation of insulin resistance in a large population based study, a total of 2420 subjects without diabetes from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study were assessed. Dietary Se intake was evaluated from the Willett Food Frequency questionnaire. Fasting blood samples were used for the measurement of glucose and insulin. Insulin resistance was determined with the homeostasis model assessment (HOMA-IR). Body composition was measured using dual energy X-ray absorptiometry. Analysis of covariance showed that high HOMA-IR groups in both males and females had the lowest dietary Se intake (μg/kg/day) (p < 0.01), being 18% and 11% lower than low HOMA-IR groups respectively. Insulin resistance decreased with the increase of dietary Se intake in females but not in males after controlling for age, total calorie intake, physical activity level, serum calcium, serum magnesium, and body fat percentage (p < 0.01). Partial correlation analysis showed that dietary Se intake was negatively correlated with HOMA-IR after adjusting for the Se confounding factors in subjects whose dietary Se intake was below 1.6 μg/kg/day (r = -0.121 for males and -0.153 for females, p < 0.05). However, the negative correlation was no longer significant when dietary Se intake was above 1.6 μg/kg/day. Our findings suggest that higher dietary Se intake is beneficially correlated with lower insulin resistance when total dietary Se intake was below 1.6 μg/kg/day. Above this cutoff, this beneficial effect disappears.

Self-Report Dietary Assessment Tools Used in Canadian Research: A Scoping Review

Choosing the most appropriate dietary assessment tool for a study can be a challenge. Through a scoping review, we characterized self-report tools used to assess diet in Canada to identify patterns in tool use and to inform strategies to strengthen nutrition research. The research databases Medline, PubMed, PsycINFO, and CINAHL were used to identify Canadian studies published from 2009 to 2014 that included a self-report assessment of dietary intake. The search elicited 2358 records that were screened to identify those that reported on self-report dietary intake among nonclinical, non-Aboriginal adult populations. A pool of 189 articles (reflecting 92 studies) was examined in-depth to assess the dietary assessment tools used. Food-frequency questionnaires (FFQs) and screeners were used in 64% of studies, whereas food records and 24-h recalls were used in 18% and 14% of studies, respectively. Three studies (3%) used a single question to assess diet, and for 3 studies the tool used was not clear. A variety of distinct FFQs and screeners, including those developed and/or adapted for use in Canada and those developed elsewhere, were used. Some tools were reported to have been evaluated previously in terms of validity or reliability, but details of psychometric testing were often lacking. Energy and fat were the most commonly studied, reported by 42% and 39% of studies, respectively. For ∼20% of studies, dietary data were used to assess dietary quality or patterns, whereas close to half assessed ≤5 dietary components. A variety of dietary assessment tools are used in Canadian research. Strategies to improve the application of current evidence on best practices in dietary assessment have the potential to support a stronger and more cohesive literature on diet and health. Such strategies could benefit from national and global collaboration.

Magnesium Status and Its Association with Oxidative Stress in Obese Women

The aim of this study was to assess the relationship between magnesium status and oxidative stress in obese and nonobese women. This cross-sectional study included 83 women, aged between 20 and 50 years, who were divided into two groups: the obese group (n = 31) and the control group (n = 52). The control group was age-matched with the obese group. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma and erythrocyte magnesium concentrations were determined by flame atomic absorption spectrophotometry. Plasma levels of thiobarbituric acid reactive substances (TBARS) were determined as biomarkers for lipid peroxidation and therefore of oxidative stress. The mean values of the magnesium content in the diet were found to be lower than those recommended, though there was no significant difference between groups (p > 0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p > 0.05). The mean concentration of plasma TBARS was higher in obese woman, and the difference between the groups was statistically different (p < 0.05). There was a positive correlation between erythrocyte magnesium and plasma TBARS in the obese group (p = 0.021). Obese patients ingest low dietary magnesium content, which does not seem to affect the plasma and erythrocyte concentrations of the mineral. The study showed a negative correlation between erythrocyte magnesium concentrations and plasma TBARS, suggesting the influence of magnesium status on the parameters of oxidative stress in obese women.

Efficacy of Magnesium Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Meta-analysis

Objective

To evaluate if magnesium supplementation, in addition to standard therapy, improves fasting blood sugar (FBS) and/or glycosylated hemoglobin (HbA1c) in patients with type 2 diabetes mellitus (T2DM) compared to placebo or other comparator.

Methodology

We searched MEDLINE/PubMed, Cochrane Library, Acta Medica Philippina, Health Research and Development Information Network (HERDIN) and references of reviewed journals from 1966 to July 2015 using the following search terms: “magnesium” OR “magnesium supplementation” OR “magnesium replacement”, AND randomized controlled trial AND diabetes OR diabetes mellitus OR non-insulin dependent diabetes mellitus OR diabetic OR diab* (with MeSH, where available). Studies were retrieved and rated independently using the standards provided by The Cochrane Collaboration. High quality trials were included in a systematic review and meta-analysis.

Results

Of the 689 records screened, 10 studies were included in the qualitative synthesis and 7 studies in the meta-analysis. Pooled data showed a non-significant trend towards improvement in glycemic control in the magnesium-treated group (mean difference -0.19, CI -0.58 to 0.21). There was a stronger but still non-significant trend in T2DM patients with hypomagnesemia (mean difference -1.16, CI -2.92 to 0.6).

Conclusion

Routine magnesium supplementation for improvement in glycemic control in T2DM patients cannot be recommended based on data from included studies in this meta-analysis.

Assessment of mineral intake in the diets of Polish postmenopausal women in relation to their BMI-the RAC-OST-POL study : Mineral intake in relation to BMI

BACKGROUND

The diets of postmenopausal women in Western countries tend to be deficient in minerals, even if the energy value is at the recommended level. The objective of the presented population-based cohort study was to assess the intake of minerals (sodium, potassium, calcium, phosphorus, magnesium, iron, zinc and copper) in the diets of women aged above 55 years and to analyse the relations between BMI and mineral intake in this group.

METHODS

The study was conducted in a group of 406 women who were randomly recruited from the general population of those aged above 55 years. The main outcome measures included BMI, reported sodium, potassium, calcium, phosphorus, magnesium, iron, zinc and copper intake assessed by dietary record (conducted during two typical, non-consecutive days). The distribution was verified with the use of the Shapiro-Wilk test. The comparison between groups was conducted using ANOVA with the LSD post hoc test or Kruskal-Wallis ANOVA with multiple comparisons. A comparison of satisfying nutritional needs was conducted using the chi-square test.

RESULTS

Normal body weight individuals were characterised by lower sodium intake per 1000 kcal of diet than obese class II and III individuals (BMI ≥ 35.0 kg/m(2)). Overweight individuals were characterised by lower potassium and magnesium intake per 1000 kcal of diet than obese class I individuals (BMIϵ < 30.0; 35.0 kg/m(2)). The majority of individuals was characterised by insufficient potassium, calcium and magnesium intake. No differences in satisfying nutritional needs between BMI groups were observed for all minerals.

CONCLUSIONS

Following an improperly balanced diet was observed in the group of postmenopausal female individuals analysed. It was stated that the daily intake of all the assessed minerals was not BMI-dependent for the postmenopausal female individuals, but the nutrient density of diet (for sodium, potassium and magnesium) was associated with BMI.

Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada

Background

Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.

Objective

To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study.

Design

A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics) study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.

Result

Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), percent gynoid fat (%GF) and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all). Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001). Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.

Conclusion

Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body composition in humans.

Moderately Low Magnesium Intake Impairs Growth of Lean Body Mass in Obese-Prone and Obese-Resistant Rats Fed a High-Energy Diet

The physical and biochemical changes resulting from moderately low magnesium (Mg) intake are not fully understood. Obesity and associated co-morbidities affect Mg metabolism and may exacerbate Mg deficiency and physiological effects. Male rats selectively bred for diet-induced obesity (OP, obese-prone) or resistance (OR, obese-resistant) were fed a high-fat, high-energy diet containing moderately low (LMg, 0.116 ± 0.001 g/kg) or normal (NMg, 0.516 ± 0.007 g/kg) Mg for 13 weeks. The growth, body composition, mineral homeostasis, bone development, and glucose metabolism of the rats were examined. OP and OR rats showed differences (p < 0.05) in many physical and biochemical measures regardless of diet. OP and OR rats fed the LMg diet had decreased body weight, lean body mass, decreased femoral size (width, weight, and volume), and serum Mg and potassium concentrations compared to rats fed the NMg diet. The LMg diet increased serum calcium (Ca) concentration in both rat strains with a concomitant decrease in serum parathyroid hormone concentration only in the OR strain. In the femur, Mg concentration was reduced, whereas concentrations of Ca and sodium were increased in both strains fed the LMg diet. Plasma glucose and insulin concentrations in an oral glucose tolerance test were similar in rats fed the LMg or NMg diets. These results show that a moderately low Mg diet impairs the growth of lean body mass and alters femoral geometry and mineral metabolism in OP and OR rats fed a high-energy diet.

Significant Beneficial Association of High Dietary Selenium Intake with Reduced Body Fat in the CODING Study

Selenium (Se) is a trace element which plays an important role in adipocyte hypertrophy and adipogenesis. Some studies suggest that variations in serum Se may be associated with obesity. However, there are few studies examining the relationship between dietary Se and obesity, and findings are inconsistent. We aimed to investigate the association between dietary Se intake and a panel of obesity measurements with systematic control of major confounding factors. A total of 3214 subjects participated in the study. Dietary Se intake was determined from the Willett food frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry. Obese men and women had the lowest dietary Se intake, being 24% to 31% lower than corresponding normal weight men and women, classified by both BMI and body fat percentage. Moreover, subjects with the highest dietary Se intake had the lowest BMI, waist circumference, and trunk, android, gynoid and total body fat percentages, with a clear dose-dependent inverse relationship observed in both gender groups. Furthermore, significant negative associations discovered between dietary Se intake and obesity measurements were independent of age, total dietary calorie intake, physical activity, smoking, alcohol, medication, and menopausal status. Dietary Se intake alone may account for 9%–27% of the observed variations in body fat percentage. The findings from this study strongly suggest that high dietary Se intake is associated with a beneficial body composition profile.

Magnesium Status and Its Relationship with C-Reactive Protein in Obese Women

This study assessed the relationship between magnesium status and C-reactive protein concentration in obese and nonobese women. This cross-sectional study included 131 women, aged between 20 and 50 years, who were divided into two groups: obese (n=65) and control (n=66) groups. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma, erythrocyte, and urinary magnesium concentrations were determined by flame atomic absorption spectrophotometry. C-reactive protein concentration in serum was measured by immunoturbidimetric assay. The mean values of the magnesium content in the diet were lower than those recommended, though there was no significant difference between groups (p>0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p>0.05). Urinary excretion of this mineral was less than the reference values in both groups, with no significant difference (p>0.05). The mean concentration of serum C-reactive protein was within the normal range in both groups, with no significant difference (p>0.05). There was a positive correlation between urinary magnesium and serum C-reactive protein (p=0.015). Obese patients ingest low dietary magnesium content, which seems to induce hypomagnesuria as a compensatory mechanism to keep plasma concentrations of the mineral at adequate levels. The study shows a positive correlation between urinary magnesium concentrations and serum C-reactive protein, suggesting the influence of hypomagnesuria on this inflammatory protein in obese women.

Lower serum magnesium concentration is associated with diabetes, insulin resistance, and obesity in South Asian and white Canadian women but not men

Background

A large proportion of adults in North America are not meeting recommended intakes for magnesium (Mg). Women and people of South Asian race may be at higher risk for Mg deficiency because of lower Mg intakes relative to requirements and increased susceptibility to diabetes, respectively.

Objective

This study compared serum Mg concentrations in South Asian (n=276) and white (n=315) Canadian women and men aged 20–79 years living in Canada's Capital Region and examined the relationship with diabetes, glucose control, insulin resistance, and body mass index.

Results

Serum Mg concentration was lower in women of both races and South Asians of both genders. Racial differences in serum Mg were not significant after controlling for use of diabetes medication. A substantial proportion of South Asian (18%) and white (9%) women had serum Mg <0.75 mmol/L indicating hypomagnesemia. Use of diabetes medication and indicators of poorer glucose control, insulin resistance, and obesity were associated with lower serum Mg in women, but not in men.

Conclusions

These results suggest that the higher incidence of diabetes in South Asians increases their risk for Mg deficiency and that health conditions that increase Mg requirements have a greater effect on Mg status in women than men.

Hormonal and dietary characteristics in obese human subjects with and without food addiction

The concept of food addiction (FA) is a potentially important contributing factor to the development of obesity in the general population; however, little is known about the hormonal and dietary differences between obesity with and without FA. Therefore, the aim of our study was to explore potential biomarkers, including various hormones and neuropeptides, which regulate appetite and metabolism, and dietary components that could potentially differentiate obesity with and without FA. Of the 737 adults recruited from the general Newfoundland population, 58 food-addicted and non-food-addicted overweight/obese individuals (FAO, NFO) matched for age, sex, BMI and physical activity were selected. A total of 34 neuropeptides, gut hormones, pituitary polypeptide hormones and adipokines were measured in fasting serum. We found that the FAO group had lower levels of TSH, TNF-α and amylin, but higher levels of prolactin, as compared to NFO group. The total calorie intake (per kg body weight), the dietary intake of fat (per g/kg body weight, per BMI and per percentage of trunk fat) and the percent calorie intake from fat and carbohydrates (g/kg) was higher in the FAO group compared to the NFO group. The FAO subjects consumed more sugar, minerals (including sodium, potassium, calcium and selenium), fat and its components (such as saturated, monounsaturated and trans fat), omega 3 and 6, vitamin D and gamma-tocopherol compared to the NFO group. To our knowledge, this is the first study indicating possible differences in hormonal levels and micro-nutrient intakes between obese individuals classified with and without food addiction. The findings provide insights into the mechanisms by which FA could contribute to obesity.

Dietary magnesium intake and metabolic syndrome in the adult population: dose-response meta-analysis and meta-regression

ncreasing evidence has suggested an association between dietary magnesium intake and metabolic syndrome. However, previous research examining dietary magnesium intake and metabolic syndrome has produced mixed results. Our objective was to determine the relationship between dietary magnesium intake and metabolic syndrome in the adult population using a dose-response meta-analysis. We searched the PubMed, Embase and the Cochrane Library databases from August, 1965, to May, 2014. Observational studies reporting risk ratios with 95% confidence intervals (CIs) for metabolic syndrome in ≥ 3 categories of dietary magnesium intake levels were selected. The data extraction was performed independently by two authors, and the quality of the studies was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS). Based on eight cross-sectional studies and two prospective cohort studies, the pooled relative risks of metabolic syndrome per 150 mg/day increment in magnesium intake was 0.88 (95% CI, 0.84-0.93; I(2) = 36.3%). The meta-regression model showed a generally linear, inverse relationship between magnesium intake (mg/day) and metabolic syndrome. This dose-response meta-analysis indicates that dietary magnesium intake is significantly and inversely associated with the risk of metabolic syndrome. However, randomized clinical trials will be necessary to address the issue of causality and to determine whether magnesium supplementation is effective for the prevention of metabolic syndrome.

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.

Influence of magnesium on insulin resistance in obese women

The present study evaluated the influence of magnesium on insulin resistance in obese women. A case-control study involving 114 women on the age between 20 and 50 years old, divided into two groups: control (eutrophic women, n = 59) and case (obese women, n = 55). The analysis of magnesium intake was carried out through the 3-day food record and also NutWin software version 1.5. The plasma, erythrocyte, and urinary magnesium concentrations were determined by flame atomic absorption spectrophotometry. The determinations of serum glucose and serum insulin were performed by enzymatic colorimetric method and chemiluminescence, respectively. The insulin resistance was assessed by homeostasis model assessment insulin resistance (HOMA-IR). The mean values of magnesium intake were lower than those recommended, without difference between groups (p > 0.05). All the patients who were evaluated showed adequate mean concentrations of magnesium in the plasma and erythrocyte. The urinary excretion of this mineral was lower than the reference values in both groups and did not show significant difference (p > 0.05). The values of serum glucose, serum insulin, and HOMA-IR were higher in obese women compared to the control group. A negative correlation was observed between erythrocyte magnesium and glycemic parameters (p < 0.05). Obese patients take in foods with low dietary magnesium content, and they show hypomagnesuria as a compensatory mechanism to keep the plasma concentration of this mineral in adequate levels. The correlation between the erythrocyte magnesium concentration and the parameters of glycemic control suggests the influence of this mineral on the index of insulin resistance in obese women.

Dietary magnesium and genetic interactions in diabetes and related risk factors: a brief overview of current knowledge

Nutritional genomics has exploded in the last decade, yielding insights—both nutrigenomic and nutrigenetic—into the physiology of dietary interactions and our genes. Among these are insights into the regulation of magnesium transport and homeostasis and mechanisms underlying magnesium’s role in insulin and glucose handling. Recent observational evidence has attempted to examine some promising research avenues on interaction between genetics and dietary magnesium in relation to diabetes and diabetes risk factors. This brief review summarizes the recent evidence on dietary magnesium’s role in diabetes and related traits in the presence of underlying genetic risk, and discusses future potential research directions.

Circulating 25-hydroxyvitamin D is associated with insulin resistance cross-sectionally but not longitudinally in older adults: The Cardiovascular Health Study

BACKGROUND

Despite extensive study, the role of vitamin D in insulin resistance and secretion remains unclear.

OBJECTIVE

To examine the cross-sectional and longitudinal relationships between 25-hydroxyvitamin D (25(OH)D) concentrations and indices of insulin resistance and secretion in older adults.

METHODS AND RESULTS

Among 2134 participants of the Cardiovascular Health Study who were free from cardiovascular disease, we measured serum 25(OH)D concentrations in samples collected in 1992-1993. We examined insulin resistance and secretion using Homeostasis Model Assessment (HOMA) estimates cross-sectionally and among 1469 participants who had repeated HOMA measures four years later (1996-1997). In cross-sectional analysis, each 10 ng/mL increment in 25(OH)D concentration was associated with a 0.09 lower adjusted HOMA-IR [95% CI (-0.17, -0.02), p=0.01]. However, baseline 25(OH)D concentrations were not associated with change in HOMA-IR over 4 years of follow up (p=0.48). 25(OH)D concentrations were not associated with insulin secretion, as determined by HOMA-β, in either cross-sectional or longitudinal analysis.

CONCLUSIONS

Circulating 25(OH)D concentrations are associated with lower insulin resistance in cross-sectional but not longitudinal analyses. Whether this reflects residual confounding in cross-sectional analyses or the short-term nature of the relationship between vitamin D and insulin sensitivity will require trials with repeated measures of these factors.

Dietary magnesium intake improves insulin resistance among non-diabetic individuals with metabolic syndrome participating in a dietary trial

Many cross-sectional studies show an inverse association between dietary magnesium and insulin resistance, but few longitudinal studies examine the ability to meet the Recommended Dietary Allowance (RDA) for magnesium intake through food and its effect on insulin resistance among participants with metabolic syndrome (MetS). The dietary intervention study examined this question in 234 individuals with MetS. Magnesium intake was assessed using 24-h dietary recalls at baseline, 6, and 12 months. Fasting glucose and insulin levels were collected at each time point; and insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). The relation between magnesium intake and HOMA-IR was assessed using linear mixed models adjusted for covariates. Baseline magnesium intake was 287 ± 93 mg/day (mean ± standard deviation), and HOMA-IR, fasting glucose and fasting insulin were 3.7 ± 3.5, 99 ± 13 mg/dL, and 15 ± 13 μU/mL, respectively. At baseline, 6-, and 12-months, 23.5%, 30.4%, and 27.7% met the RDA for magnesium. After multivariate adjustment, magnesium intake was inversely associated with metabolic biomarkers of insulin resistance (P < 0.01). Further, the likelihood of elevated HOMA-IR (>3.6) over time was 71% lower [odds ratio (OR): 0.29; 95% confidence interval (CI): 0.12, 0.72] in participants in the highest quartile of magnesium intake than those in the lowest quartile. For individuals meeting the RDA for magnesium, the multivariate-adjusted OR for high HOMA-IR over time was 0.37 (95% CI: 0.18, 0.77). These findings indicate that dietary magnesium intake is inadequate among non-diabetic individuals with MetS and suggest that increasing dietary magnesium to meet the RDA has a protective effect on insulin resistance.