Association of serum magnesium with metabolic syndrome and the role of chronic kidney disease: A population-based cohort study with Mendelian randomization

OBJECTIVES

To assess the association of serum magnesium with prevalent and incident metabolic syndrome (MetS) and its individual components in the general population and to examine any effect modification by chronic kidney disease (CKD) status.

METHODS

We analysed longitudinal data from the population-based KORA F4/FF4 study, including 2996 participants (387 with CKD) for cross-sectional analysis and 1446 participants (88 with CKD) for longitudinal analysis. Associations with MetS, as well as single components of MetS, were assessed by adjusted regression models. Nonlinearity was tested by restricted cubic splines and analyses were stratified by CKD. Causality was evaluated by two-sample Mendelian randomization (MR).

RESULTS

Serum magnesium (1 SD) was inversely associated with prevalent MetS (odds ratio [OR] 0.90, 95% confidence interval [CI] 0.83, 0.98). The association was more pronounced in individuals with CKD (OR 0.75, 95% CI 0.59, 0.94). Among MetS components, serum magnesium was negatively associated with elevated fasting glucose (OR 0.78, 95% CI 0.71, 0.88) and, again, this association was more pronounced in individuals with CKD (OR 0.67, 95% CI 0.53, 0.84). Serum magnesium was not associated with incident MetS or its components. Restricted cubic spline analysis revealed a significant nonlinear inverse relationship of serum magnesium with MetS and elevated fasting glucose. MR analysis suggested an inverse causal effect of serum magnesium on MetS (OR 0.91, 95% CI 0.85, 0.97).

CONCLUSION

Serum magnesium is associated with prevalent, but not incident MetS, and this effect is stronger in individuals with CKD. MR analysis implies a potential, albeit weak, causal role of magnesium in MetS.

Associations among diabetes medication use, serum magnesium, and insulin resistance in a cohort of older Puerto Rican adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVES

We aimed to examine the association between diabetes medication and hypomagnesemia and evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n = 1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg <0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-y HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) of ≥6.5%.

RESULTS

Mean age at baseline was 59.0 ± 7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

Frequency of Hypomagnesemia and Its Relationship With Severity Among Patients of Acute Ischemic Stroke Presenting to a Tertiary Care Hospital

Objective The objective of this study was to assess the prevalence of hypomagnesemia and its association with the severity of acute ischemic stroke (AIS) in patients presenting at a tertiary care hospital. Methodology A total of 100 patients with AIS were included in the study. Demographic data, including age, gender, and severity of stroke, were collected. Serum magnesium levels were measured at admission, and the severity of stroke was classified as mild, moderate, or severe based on clinical criteria. The presence of hypomagnesemia was defined as a serum magnesium level below 1.8 mg/dL determined within 72 hours of onset of stroke. Statistical analysis was performed to assess the association between hypomagnesemia, stroke severity, age, and gender. Results The mean age of the patients with standard deviation was 65.45 ± 11.8 years, with the majority (38, 38%) aged 60-74 years. There were 53 (53%) male and 47 (47%) female patients. Hypomagnesemia was found in 35 (35%) patients, with an average magnesium level of 1.93 mg/dL and a standard deviation of 0.37 at admission. There was no statistically significant difference in the distribution of stroke severity (P = 0.779; P = 0.406) or hypomagnesemia (P = 0.287; P = 0.591) based on gender or age group, respectively. Stratification based on stroke severity showed that 16 (39%) patients with mild stroke, 10 (31.3%) with moderate stroke, and 9 (33.3%) with severe stroke had hypomagnesemia. The correlation between stroke severity and hypomagnesemia was weak (r = 0.099). Further, among hypomagnesemia patients, the majority were females aged 60-74 years. Conclusions This study found a weak positive relationship between the severity of AIS and the presence of hypomagnesemia. However, no statistically significant association was observed between gender or age group and stroke severity or hypomagnesemia. These findings suggest that further research is needed to understand the role of hypomagnesemia in AIS and its potential implications for patient management.

Association of maternal serum magnesium with pre-eclampsia in African pregnant women: a systematic review and meta-analysis

Pre-eclampsia (PE) is a pregnancy-related disorder characterized by hypertension and proteinuria occurring after 20 weeks of gestation. Several studies have been performed to determine the serum magnesium (Mg) level in PE, but most report inconclusive results. Consequently, this study was designed to resolve this controversy among African women. PubMed, Hinari, Google Scholar and African Journals Online electronic databases were searched for studies published in English. The qualities of included articles were appraised using the Newcastle-Ottawa quality assessment tool. Stata 14 software was utilized for analysis and serum Mg levels in cases and normotensive controls were compared through mean and standardized mean difference (SMD) at the 95% confidence interval (CI). In this review, we found that the mean serum Mg level was significantly reduced in cases (0.910±0.762 mmol/L) vs controls (1.167±1.060 mmol/L). The pooled SMD of serum Mg was significantly lower in cases (-1.20 [95% CI -1.64 to -0.75]). Therefore, since serum Mg is reduced in cases vs controls, we propose that Mg is involved in the pathophysiology of PE. Nevertheless, to know the exact mechanisms of Mg in PE development will require large-scale prospective studies.

Evaluating Serum Calcium and Magnesium Levels as Predictive Biomarkers for Tuberculosis and COVID-19 Severity: A Romanian Prospective Study

In Romania, the highest incidence of tuberculosis (TB) within the European Union was reported in 2020, highlighting a significant health challenge. This is compounded by the COVID-19 pandemic, which has severely impacted healthcare services, including TB management. Both TB and COVID-19, diseases with considerable morbidity and mortality, have shown potential links to electrolyte imbalances. We conducted a prospective study at Victor Babes Hospital, Romania on 146 patients (74 with TB, 72 with COVID-19) between December 2021 and July 2023. This study assessed correlations between disease severity and serum calcium and magnesium levels, as well as pulmonary function. Adult patients with confirmed diagnoses and comprehensive medical records were included, excluding those with chronic respiratory diseases or unrelated electrolyte imbalances. Statistical analysis utilized the Kruskal-Wallis test and Dunn's procedure for non-normally distributed data. Low serum calcium and magnesium levels were significantly correlated with severe forms of TB and COVID-19, suggesting their potential as biomarkers of disease progression. Patients with more severe TB (i.e., multiple cavities) exhibited significantly lower serum calcium (p = 0.0049) and magnesium levels (p = 0.0004). ROC analysis revealed high AUC values for serum calcium and serum magnesium in predicting COVID-19 severity, indicating their potential as biomarkers. This study demonstrates a significant association between lower serum calcium and magnesium levels and increased TB severity. Similarly, these electrolytes show promise as predictive markers for COVID-19 severity. These findings could serve as biomarkers for predicting the severity of TB and COVID-19, offering potential utility in clinical decision-making.

Relationship between short-term self-reported dietary magnesium intake and whole blood ionized magnesium (iMg2+) or serum magnesium (s-Mg) concentrations

OBJECTIVE

Since we and others have shown that supplemental magnesium raises whole blood ionized magnesium (iMg²⁺) we investigated the relationships between self-reported dietary magnesium intake and concentrations of whole blood iMg²⁺ and serum magnesium (s-Mg).

METHODS

We obtained whole blood iMg²⁺ concentrations, as well as s-Mg concentrations, from a pilot, three-arm, randomized, controlled, crossover bioavailability study of magnesium supplements (n = 23; 105 measures). Dietary magnesium intake was assessed using three-day food records and the Nutrition Data System for Research (NDSR, University of Minnesota, MN, USA). Whole blood iMg²⁺ was measured with an electrode analyser (NOVA Biochemical, Waltham, MA, USA), whereas s-Mg was measured using atomic absorption spectroscopy. A linear mixed-effects model was employed with dietary magnesium as the outcome variable and iMg²⁺, s-Mg, study treatment and study visit as fixed effects. We adjusted age, gender, race and body mass index covariates.

RESULTS

Values for dietary magnesium, iMg²⁺ and s-Mg were 303.8 ± 118.9 mg/day, 1.3 ± 0.1 mg/dL and 2.2 ± 4.1 mg/dL, respectively. No association was found between dietary magnesium intake and iMg²⁺ -125 ± 176.95 (p = .49) or s-Mg -9.33 ± 5.04 (p = .08).

CONCLUSIONS

Whole blood iMg²⁺ and s-Mg concentrations do not reflect short-term self-reported dietary intake in adults. Further research is needed to determine whether blood biomarkers of magnesium may reflect dietary magnesium intake.Key messagesDietary intake of magnesium, a shortfall nutrient, may be objectively measured using blood biomarkers of magnesium.Serum magnesium and whole blood iMg²⁺ were not associated with short-term dietary intake of magnesium.

Systematic Review and Meta-Analysis to Estimate a Reference Range for Circulating Ionized Magnesium Concentrations in Adult Populations

BACKGROUND

There is a lack of consensus on a reference range for ionized magnesium (iMg2+) in blood as a measure of the status of circulating iMg2+ for the screening of populations.

OBJECTIVES

We estimated the reference range of iMg2+ levels for healthy adult populations and the ranges for populations with cardiovascular disease (CVD), type 2 diabetes, hypertension, and renal disease. We also estimated 95% ranges for circulating magnesium (Mg) in healthy and those with cardiometabolic diseases.

METHODS

We searched Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and Embase through 24 July, 2020 to identify articles. We included English, peer-reviewed, randomized controlled trials, prospective and retrospective cohort studies, case-control studies, and cross-sectional studies that measured iMg2+ in blood or circulating Mg at baseline. The protocol was registered on PROSPERO (CRD42020216100). Estimated ranges were calculated by employing a frequentist random-effects model using extracted (or calculated) means and SDs from each included study. We determined the 95% confidence interval of the pooled mean.

RESULTS

A total of 95 articles were included with 53 studies having data for healthy participants and 42 studies having data for participants with cardiometabolic diseases. The estimated reference range for iMg2+ for healthy populations was 0.40-0.68 mmol/L, 0.38-0.64 mmol/L for CVD, 0.34-0.66 mmol/L for type 2 diabetes, 0.39-1.04 mmol/L for hypertension, and 0.40-0.76 mmol/L for renal disease. For circulating Mg, the estimated range was 0.72-1.0 mmol/L for healthy adults, 0.56-1.05 mmol/L for CVD, 0.58-1.14 mmol/L for type 2 diabetes, 0.60-1.08 mmol/L for hypertension, and 0.59-1.26 mmol/L for renal disease.

CONCLUSIONS

Estimated reference ranges for cardiometabolic disease states for both iMg2+ and circulating Mg were broad and overlapped with the estimated range for healthy populations (0.40-0.68 mmol/L). Further studies should evaluate whether iMg2+ can be used as a biomarker of cardiometabolic disease.

The impact of serum magnesium and calcium on the risk of epilepsy: A mendelian randomization study

AIMS

To investigate the causal role of serum magnesium and calcium in epilepsy or any of its subtypes through Mendelian randomization (MR) approach.

METHODS

Single nucleotide polymorphisms (SNPs) associated with serum magnesium and calcium were used as the instrumental variables. MR analyses were performed using the summary-level data for epilepsy extracted from International League Against Epilepsy Consortium (15,212 cases and 29,677 controls) to obtain the causal estimates. The analyses were replicated using FinnGen data (7224 epilepsy cases and 208,845 controls), and a meta-analysis was then conducted.

RESULTS

The result of combined analyses showed that higher serum magnesium concentrations was associated with a reduced risk of overall epilepsy (odds ratios [OR] = 0.28, 95% confidence interval [CI], 0.12-0.62, p = 0.002). In ILAE, higher serum magnesium was suggestively associated with reduced risks of focal epilepsy (OR = 0.25, 95% CI 0.10-0.62, p = 0.003). However, the results cannot be repeated in sensitivity analyses. As for serum calcium, the results did not reach statistical significance with overall epilepsy (OR = 0.60, 95% CI, 0.31-1.17, p = 0.134). However, genetically predicted serum calcium concentrations showed an inverse association with risk of generalized epilepsy (OR = 0.35, 95% CI, 0.17-0.74, p = 0.006).

CONCLUSION

The current MR analysis did not support a causal relationship between serum magnesium and epilepsy, but showed a causally negative association between genetically determined serum calcium and generalized epilepsy.

Importance of Magnesium Status in COVID-19

A large amount of published research points to the interesting concept (hypothesis) that magnesium (Mg) status may have relevance for the outcome of COVID-19 and that Mg could be protective during the COVID disease course. As an essential element, Mg plays basic biochemical, cellular, and physiological roles required for cardiovascular, immunological, respiratory, and neurological functions. Both low serum and dietary Mg have been associated with the severity of COVID-19 outcomes, including mortality; both are also associated with COVID-19 risk factors such as older age, obesity, type 2 diabetes, kidney disease, cardiovascular disease, hypertension, and asthma. In addition, populations with high rates of COVID-19 mortality and hospitalization tend to consume diets high in modern processed foods, which are generally low in Mg. In this review, we review the research to describe and consider the possible impact of Mg and Mg status on COVID-19 showing that (1) serum Mg between 2.19 and 2.26 mg/dL and dietary Mg intakes > 329 mg/day could be protective during the disease course and (2) inhaled Mg may improve oxygenation of hypoxic COVID-19 patients. In spite of such promise, oral Mg for COVID-19 has thus far been studied only in combination with other nutrients. Mg deficiency is involved in the occurrence and aggravation of neuropsychiatric complications of COVID-19, including memory loss, cognition, loss of taste and smell, ataxia, confusion, dizziness, and headache. Potential of zinc and/or Mg as useful for increasing drug therapy effectiveness or reducing adverse effect of anti-COVID-19 drugs is reviewed. Oral Mg trials of patients with COVID-19 are warranted.

Serum Magnesium in Patients With Acute Myocardial Infarction and Its Effect on Cardiac Complications and Mortality in Myocardial Infarction Patients

Background Magnesium is an essential micronutrient for people and is crucial in maintaining healthy cardiac function. It functions as a cofactor in a number of the body's enzyme systems, and myocardial cells are one of its target tissues. The upkeep of the myocardium's normal functional integrity depends on a lot of things including magnesium ions. Magnesium plays an important role in the pathophysiology of cardiovascular disorders. Aim This study aims to estimate serum magnesium levels and their correlation with cardiac complications and mortality in patients with acute myocardial infarction (AMI). Methods Patients with acute myocardial infarction who visited the Prince Faisal Bin Khalid Cardiac Center within 12 hours of the onset of symptoms were the subjects of this study. On the first and fifth days following admission, the level of serum magnesium was assessed. Statistical Package for Social Sciences (SPSS) version 20 (IBM SPSS Statistics, Armonk, NY) was used to analyze the collected data. Results The current study comprised 160 patients with acute myocardial infarction; there were 84 (52.5%) who experienced a low level of serum magnesium on admission. Significantly higher proportions of patients who experienced low magnesium levels had diabetes mellitus (P=0.0072) and a history of diuretics (P=0.03) and were administrated beta-blockers (P=0.01), calcium channel blockers (P=0.04), and statins (P=0.007) after admission. Significantly higher proportions of patients with low serum magnesium experienced atrial fibrillation (P=0.03), angina (P=0.03), and cardiogenic shock (P=0.003). Conclusion Low magnesium levels are associated with poor outcomes in most patients admitted with acute myocardial infarction.

Elevated C-Reactive Protein Levels Modify the Effect of Magnesium on Depressive Symptoms: A Population-Based Study

Depression is a profound public health concern, yet its etiology remains unclear. A body's magnesium status and low-grade systemic inflammation are associated with depression. However, the interaction of magnesium status and inflammation on depression/depressive symptoms is unknown. We assessed the association between serum magnesium levels and depressive symptoms by analyzing data from the Nutrition and Health Survey in Taiwan 2005-2008. In total, 2196 participants aged ≥20 years were included. Depressive symptoms were assessed using the 5-item Brief-Symptom Rating Scale. We performed logistic regression and multiple linear regression analyses to examine the association. A dose-response analysis was performed using restricted cubic spline models, and stratification by chronic inflammation was also performed. We found that higher serum magnesium levels were associated with lower depression scores and a lower risk of depression. In the subgroup analysis, serum magnesium levels were inversely associated with depressive symptoms more prominently among people with higher CRP levels, with a threshold at 5 mg/L (≥5 vs. <5) showing a greater difference than at 3 mg/L (≥3 vs. <3). Conclusions: Serum magnesium levels were inversely associated with depressive symptoms. This inverse association was affected by inflammation level. A dose-response relationship was also observed.

The association of serum magnesium with infection in new-onset systemic lupus erythematosus patients

OBJECTIVE

To assess the association of serum magnesium with infection in new-onset systemic lupus erythematosus (SLE) patients.

METHODS

We conducted a single-center retrospective cohort study of new-onset SLE patients from 2012 to 2021. The hospitalized SLE patients were divided into infection and noninfection groups. Logistic regression analysis was conducted to examine the association of hypomagnesemia with infection.

RESULTS

A total of 476 new-onset SLE patients were included, with 299 cases in the infection group and 177 cases in the noninfection group. The patients were mostly females (81.7%). The average age at diagnosis was 43.7 years. The median duration was 1.0 month. The prevalence of hypomagnesemia (<0.70), normomagnesemia (0.70-1.10), and hypermagnesemia (>1.10) in new-onset SLE patients was 14.3%, 83.4%, and 2.3%, respectively. The prevalence of hypomagnesemia was 18.4% in the infection group and 7.3% in the noninfection group (p = .001). The baseline value of serum magnesium was 0.819 mmol/L, with values of 0.799 mmol/L in the infection group and 0.854 mmol/L in the noninfection group (p = .000). The following clinical variables were significantly different between the two groups (p < .05): age, duration, hospitalization stay, fever, serositis, and SLE Disease Activity Index 2000 (SLEDAI 2K). The laboratory parameters, including hemoglobin, white blood cell count, albumin level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin, and complement C3 were also significantly different between the two groups (p < .05). The mortality was 4.4% (21/476), with 20 cases occurring in the infection group. Logistic regression analysis showed that hypomagnesemia was associated with an increased risk of infection (p = .001) and poor prognosis (p = .015).

CONCLUSION

Hypermagnesemia was rare in new-onset SLE patients. Hypomagnesemia was common and was associated with an increased risk of infection in new-onset SLE patients.

The Association of Serum and Dietary Magnesium with Depressive Symptoms

Depression is a leading cause of the global burden of disease and has a multifactorial etiology that includes nutrients. Magnesium status has been associated with depression with inconclusive results. The impact of chronic latent magnesium deficiency (CLMD, 0.75 ≤ serum magnesium < 0.85 mmol/L) on depression has not yet been investigated. We assessed the association between serum magnesium levels/dietary magnesium intake and depressive symptoms by analyzing nationally representative data from Taiwan (Nutrition and Health Survey in Taiwan, NAHSIT). We used the 5-item Brief Symptom Rating Scale to measure depressive symptoms. Subgroup analysis by sex was also performed. Serum magnesium levels had a low correlation with dietary magnesium intake. Higher serum magnesium levels were associated with lower depressive scores and a lower risk of depressive symptoms, but dietary magnesium intake showed no association. Sex differences were found. Compared with subjects with serum magnesium <0.75 mmol/L, those with ≥0.85 mmol/L had lower depressive scores. In conclusion, serum magnesium was inversely associated with depressive symptoms, but dietary magnesium intake was not. Subjects with CLMD showed similar depressive scores and were at a similar risk of depressive symptoms to those with serum magnesium < 0.75 mmol/L. CLMD should be considered while assessing the association between magnesium status and depressive symptoms.

Serum Magnesium is Inversely Associated with Body Composition and Metabolic Syndrome

PURPOSE

Magnesium is vital to maintain normal physiological functions. We aimed to identify the association between serum magnesium and different measures of body adiposity among Qatari adults. We hypothesized that the association was mediated by depression and sleep duration.

PATIENTS AND METHODS

The study included 1000 adults aged 20 years and above who attended the Qatar Biobank Study (QBB) between 2012 and 2019. Body adiposity was assessed using dual-energy X-ray absorptiometry (DEXA). Serum magnesium concentration was measured. Sub-optimal magnesium was defined as magnesium concentration less than 0.85 mmol/L. The association was examined using linear regression.

RESULTS

The mean age of the participants (n=1000) was 35.8 (SD 10.3) years. More than half of the participants had sub-optimal magnesium concentrations (60.2% in men and 52.3% in women). Serum magnesium was inversely associated with different types of fat mass. In the fully adjusted model, per 1 SD increment of serum magnesium had standardized regression coefficients of -0.09 (p 0.005) for total fat mass, -0.08 (p 0.008) for trunk fat, -0.09 (p 0.003) for gynoid fat and -0.08 (p 0.008) for android fat. There was no gender difference in the association. The inverse association between serum magnesium and fat mass was significant in those with sleep duration ≥7 hours but not in those <7 hours. Depressive symptom and sleep did not mediate the association between serum magnesium and fat mass. Serum magnesium was inversely associated with metabolic syndrome (per 1 SD increment had an odds ratio (OR) of 0.70 (95% CI 0.57-0.85)).

CONCLUSION

There was an inverse association between serum magnesium and fat mass, especially among those with an adequate sleep duration and without chronic conditions including diabetes, hypertension and depression.

Low serum magnesium is associated with poor functional outcome in acute ischemic stroke or transient ischemic attack patients

AIM

The association between magnesium and outcomes after stroke is uncertain. We aimed to investigate the association of serum magnesium with all-cause mortality and poor functional outcome.

METHODS

We included patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) from the China National Stroke Registry III. We used Cox proportional hazards model for all-cause mortality and logistic regression model for poor functional outcome (modified Rankin Scale [mRS] 2-6/3-6) to examine the relationships.

RESULTS

Among the 6483 patients, the median (interquartile range) magnesium was 0.87 (0.80-0.93) mmol/L. Patients in the first quartile had a higher risk of mRS score 3-6/2-6 at 3 months (adjusted odds ratio [OR]: 1.30; 95% confidence interval [CI]: 1.02, 1.64; adjusted OR: 1.29; 95% CI: 1.04-1.59) compared with those in the fourth quartile. Similar results were found for mRS score 26 at 1 year. The age- and sex-adjusted hazard ratio (HR) with 95% CI in first quartile magnesium was 1.40 (1.02-1.93) for all-cause mortality within 1 year, but became insignificant (HR: 1.03; 95% CI: 0.71-1.50) after adjusting for potential variables.

CONCLUSIONS

Low serum magnesium was associated with a high risk of poor functional outcome in patients with AIS or TIA.

Association of Serum Magnesium with Insulin Resistance and Type 2 Diabetes among Adults in China

Magnesium is an essential mineral for the human body and a cofactor or activator for more than 300 enzymatic reactions, including blood glucose control and insulin release. Diabetes is a well-known global burden of disease with increasing global prevalence. In China, the prevalence of diabetes in adults is higher than the global average. Evidence shows that magnesium is a predictor of insulin resistance and diabetes. However, the majority of studies focus on dietary magnesium instead of serum magnesium concentration. We study the correlation of serum magnesium levels with insulin resistance and Type 2 diabetes. In this prospective cohort study, we included 5044 participants aged 18 years and older without insulin resistance (IR) and diabetes at the baseline from China Health and Nutrition Survey (CHNS). A fasting blood sample was taken for the measurement of both types of magnesium, fasting blood glucose, hemoglobin A1c (HbA1c), and fasting insulin. The homeostatic model (HOMA-IR) was calculated. Demographic characteristics of participants, and risk factors such as intensity of physical activities, smoking status, drinking habit, and anthropometric information were recorded. IR was defined as HOMA-IR ≥ 2.5, and Type 2 diabetes mellitus was defined as fasting plasma glucose ≥ 7.0 mmol/L or HbA1c ≥ 6.5%, or a self-reported diagnosis or treatment of diabetes. A total of 1331 incident insulin resistance events and 429 incident diabetic events were recorded during an average follow-up of 5.8 years. The serum magnesium concentration was categorized into quintiles. After adjusting for relevant covariates, the third quintile of serum magnesium (0.89−0.93 mmol/L) was correlated with 29% lower risk of incident insulin resistance (hazard ratio = 0.71, 95% CI 0.58, 0.86) and with a lower risk of Type 2 diabetes. Multivariable-adjusted hazard ratios (95% confidence intervals) for insulin resistance were compared with the lowest quintile of serum magnesium (<0.85). We found similar results when evaluating serum magnesium as a continuous measure. Restricted cubic spline (RCS) curves showed a nonlinear dose−response correlation in both serum magnesium levels and insulin resistance, and in serum magnesium levels and Type 2 diabetes. Lower serum magnesium concentration was associated with a higher risk of insulin resistance and diabetes.

Causal Effect of Serum Magnesium on Osteoporosis and Cardiometabolic Diseases

Serum magnesium is associated with osteoporosis and cardiometabolic diseases, but their causal associations remain elusive. We used the two-sample Mendelian randomization (MR) study to explore the causal roles of serum magnesium on osteoporosis and cardiometabolic diseases by using the aggregated genome-wide association studies (GWASs). Six single-nucleotide polymorphisms (SNPs, p < 5 × 10^-8) associated with serum magnesium concentrations were all used as instrumental variables. A genetic predisposition to higher serum magnesium concentrations was inversely associated with lower lumbar spine bone mineral density (BMD, beta-estimate: -1.982, 95% CI: -3.328 to -0.635, SE: 0.687, p = 0.004), which was further confirmed by multiple sensitivity analyses. There was limited evidence of associations between serum magnesium and type 2 diabetes, coronary artery disease, heart failure, and atrial fibrillation. This work provided strong evidence that genetically increased serum magnesium concentrations were causally associated with low lumbar spine BMD and suggested that serum magnesium concentrations may be crucial to prevent osteoporosis.

Ventricular Arrhythmia Associated With Magnesium and Vitamin D Deficiencies in a Patient With Rheumatoid Arthritis

Prolongation of QT associated with electrolyte changes can lead to ventricular arrhythmias. Correction and supply of calcium, magnesium, and potassium are essential to managing this condition. In this report, we present a case of QT prolongation due to magnesium and vitamin D deficiency in a patient with rheumatoid arthritis.

Associations between the serum magnesium and all-cause or cardiovascular mortality in chronic kidney disease and end-stage renal disease patients: A meta-analysis

BACKGROUND

Some studies have found that hypomagnesemia is associated with vascular calcification, atherosclerosis, and cardiovascular disease, which may lead to increased mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) who need to maintain hemodialysis (HD). However, the conclusion of these studies remain controversial.

METHODS

Relevant literature was retrieved from the database of Cochrane library, PubMed, EMBASE, and CNKI until December 2020, without any language restrictions. The data was analyzed using the Stata 12.0 software.

RESULTS

A total of 31 studies were included, involving 205436 participants. The results showed that after multivariable adjusted, hypomagnesemia was significant associated with the risk of all-cause mortality in patients with CKD and end-stage renal disease (ESRD) (hazard ratios [HR] 1.955; 95% confidence interval (95% CI) 1.511-2.528; P = .000; hypomagnesemia vs normal magnesium or hypermagnesemia). In contrast, in patients with CKD and ESRD, hypermagnesemia was negatively correlated with all-cause mortality (HR 0.873; 95% CI 0.793-0.960; P = .005) (per unit increase). Moreover, in the adjusted model, it was observed that hypermagnesemia was significantly associated with a reduced risk of cardiovascular death (HR 0.598; 95% CI 0.094-1.102, P = .020). In addition, subgroup analysis found that hypomagnesemia was closely related to the increase of all-cause mortality in HD patients (HR 1.799; 95% CI 1.375-2.354; P = .000) (hypomagnesemia vs normal magnesium or hypermagnesemia).

CONCLUSION

Our results show that hypomagnesemia is significantly associated with cardiovascular and all-cause mortality in maintenance HD patients. Further studies should be conducted to evaluate the benefits of magnesium correction in maintenance dialysis patients with hypomagnesemia.

Torsades de Pointes With a Normal Magnesium Level in the Setting of Short Bowel Syndrome

Torsades de pointes (TdP) is a potentially fatal arrhythmia, typically presenting with a congenital or acquired etiology. Low serum magnesium level is a known cause leading to this arrhythmia. However, it has been found that even in the setting of a normal serum magnesium level and with no other foreseeable etiology, TdP may still occur, especially in those with chronic electrolyte deficiencies. TdP may be treated in a number of ways, including IV magnesium sulfate or defibrillation if the patient becomes unresponsive and hemodynamically unstable. In some cases, atrial overdrive is required with the use of isoproterenol. A final decision, however, would necessitate asking if the patient can be sent home on medical management to prevent recurrence of the arrhythmia or require placement of a permanent pacemaker. Here, we describe a patient developing recurrent TdP despite normal serum magnesium level in the setting of short bowel syndrome.

Magnesium levels in relation to rates of preterm birth: a systematic review and meta-analysis of ecological, observational, and interventional studies

CONTEXT

Experimental studies suggest that magnesium levels in pregnant women may affect the length of gestation, as magnesium affects the activity of smooth muscle in the uterus. Little is known about the association between magnesium levels or supplementation and the rate of preterm birth.

OBJECTIVE

The aim of this systematic review was to summarize the data on magnesium soil levels and preterm birth rates from ecological, observational, and interventional studies.

DATA SOURCES

Soil magnesium levels were obtained from US Geological Survey data, and preterm birth rates were acquired from the March of Dimes Foundation. Relevant epidemiological and clinical studies published until April 2019 in peer-reviewed journals were retrieved from PubMed, Google Scholar, and related reference lists.

STUDY SELECTION

Original studies published in English, conducted in humans, and in which magnesium (dietary/supplemental intake or biomarkers) was an exposure and preterm birth was an outcome were included.

DATA EXTRACTION

Eleven studies were included in the systematic review. Meta-analysis was performed on 6 studies. Overall relative risk (RR) and corresponding 95%CIs for risk of preterm birth in relation to magnesium supplementation were estimated by a random-effects model.

RESULTS

The ecological study revealed an inverse correlation between magnesium content in soil and rates of preterm birth across the United States (r = -0.68; P < 0.001). Findings from 11 observational studies generally support an inverse association between serum magnesium levels and rates of preterm birth. Of the 6 eligible randomized controlled trials, which included 3068 pregnant women aged 20 to 35 years and 352 preterm infants, the pooled RR was 0.58 (95%CI, 0.35-0.96) for women in the magnesium supplementation group compared with women in the control group.

CONCLUSIONS

Accumulated evidence from ecological, observational, and interventional studies consistently indicates that adequate magnesium intake during pregnancy may help reduce the incidence of preterm birth.

The ECG Characteristics of Patients With Isolated Hypomagnesemia

Background

Electrocardiographic (ECG) characteristics of patients with isolated hypomagnesemia are not well defined. We aimed to investigate these ECG characteristics in order to define clearly the features of isolated hypomagnesemia.

Hypothesis

Lower serum magnesium could affect ECG parameters after excluding potential confounders.

Methods

This retrospective study was of patients with low serum magnesium <0.65 mmol/L compared with the same patients after restoration to normal serum magnesium. Patients with hypokalemia, hypocalcemia and other electrolyte disturbances were excluded. ECG parameters manually determined and analyzed were P wave dispersion, PR interval, QRS duration, ST-T changes, T wave amplitude, T peak-to-end interval (Tpe), corrected Tpe (Tpec), QT, corrected QT (QTc), QT peak corrected (QTpc) and Tpe dispersion, Tpe/QT ratio.

Results

Two-hundred-and-fourteen patients with isolated hypomagnesemia were identified with 50 of them (56.9 ± 13.6 years; 25 males) being eligible for final analysis from 270,997 patients presenting April 2011–October 2017. In the period of isolated hypomagnesemia, P wave duration was found prolonged (p ≤ 0.02); as was QTc (439 ± 27 vs. 433 ± 22, p = 0.01). Tpec (122 ± 24vs. 111 ± 22, p = 0.000) and Tpe/QT ratio (0.29 ± 0.05 vs. 0.27 ± 0.05, p = 0.000) were increased. QTpc decreased during hypomagnesemia (334 ± 28 vs. 342 ± 21, p = 0.02). However, no significant differences were found in PR interval, QRS duration (85 ± 12 ms vs. 86 ± 12 ms, p = 0.122) and ST-T segments between the patients and their own controls.

Conclusions

In patients with isolated hypomagnesemia, P wave duration, QTc, Tpec, and Tpe/QT ratio suggesting atrial depolarization and ventricular repolarization dispersion were significantly increased compared with normal magnesium levels in the same patients after restoration to normal levels.

High-Normal Serum Magnesium and Hypermagnesemia Are Associated With Increased 30-Day In-Hospital Mortality: A Retrospective Cohort Study

Background: Magnesium, the fourth most abundant mineral nutrient in our body, plays a critical role in regulating ion channels and energy generation, intracardiac conduction, and myocardial contraction. In this study, we assessed the association of admission serum magnesium level with all-cause in-hospital mortality in critically ill patients with acute myocardial infarction (AMI).

Methods: Clinical data were extracted from the eICU Collaborative Research Database (eICU-CRD). Only the data for the first intensive care unit (ICU) admission of each patient were used, and baseline data were extracted within 24 h after ICU admission. Logistic regression, Cox regression, and subgroup analyses were conducted to determine the relationship between admission serum magnesium level and 30-day in-hospital mortality in ICU patients with AMI.

Results: A total of 9,005 eligible patients were included. In the logistic regression analysis, serum magnesium at 2.2 to ≤2.4 and >2.4 mg/dl levels were both significant predictors of all-cause in-hospital mortality in AMI patients. Moreover, serum magnesium of 2.2 to ≤2.4 mg/dl showed higher risk of in-hospital mortality than magnesium of >2.4 mg/dl (adjusted odds ratio, 1.63 vs. 1.39). The Cox regression analysis yielded similar results (adjusted hazard ratio, 1.36 vs. 1.25).

Conclusions: High-normal serum magnesium and hypermagnesemia may be useful and easier predictors for 30-day in-hospital mortality in critically ill patients with AMI.

Serum magnesium in diabetic retinopathy: the association needs investigation

BACKGROUND

Magnesium has an essential role in glucose metabolism, and hypomagnesaemia is common in diabetes mellitus. However, the relationship between serum magnesium and diabetic retinopathy is poorly understood.

AIM

To determine the association between serum magnesium levels and retinopathy in type 2 diabetic patients with normal renal function and to correlate it with severity of retinopathy.

METHODS

This cross-sectional observational study was conducted in a semi-urban tertiary-care teaching hospital. Clinicodemographic profile and serum magnesium levels were determined in patients with type 2 diabetes mellitus (DM) with (group 1) and without (group 2) retinopathy. Serum magnesium levels were correlated with the presence and severity of retinopathy.

RESULTS

Of 104 type 2 DM patients, 50 had retinopathy. Younger age, longer duration of disease and poorer glycaemic control (p < 0.05) were found to be associated with retinopathy. The mean serum magnesium levels in patients with retinopathy and those without retinopathy were 1.63 ± 0.30 mg/dL and 1.76 ± 0.22 mg/dL, respectively (p = 0.029). Reduced serum magnesium was associated with elevated fasting sugars (p = 0.019) and female gender (p = 0.037). On comparative analysis of patients with sight-threatening diabetic retinopathy (STDR), non-STDR and no retinopathy by ANOVA test, patients with STDR had significantly lower serum magnesium (1.55 ± 0.33 mg/dL) (p = 0.031).

CONCLUSION

Serum magnesium levels were lower in patients with diabetic retinopathy. Patients with STDR had lower serum magnesium compared with those without STDR.

SUMMARY

Serum magnesium, studied extensively for its role in glucose metabolism, was found to be lower in patients with diabetic retinopathy compared with those without retinopathy. Sight-threatening diabetic retinopathy had significantly lower levels of serum magnesium.

Association Between Serum Magnesium Levels and Alzheimer's Disease or Mixed Dementia Patients: A Population-Based Retrospective Controlled Study

Background

High magnesium intake has been associated with a decreased risk of dementia. In contrast, other research has found that both low and high serum magnesium levels were associated with an increased risk of Alzheimer's disease and mixed dementia. Hence, presently the role of magnesium levels in dementia is unclear.

Objective

To investigate a possible association between serum magnesium concentrations and dementia in a large population-based sample.

Methods

Maccabi Healthcare Service in Israel provides healthcare to over 2 million citizens. Maccabi maintains a registry with approximately 26,000 diagnosed dementia patients. We focused on patients of both sexes with Alzheimer's disease or mixed dementia aged 65 or older, excluding patients with clinical diagnoses that could affect serum magnesium level, or with other causes of cognitive decline. Our control group consisted of patients of the same age and sex without dementia.

Results

No significant differences were found in mean, mode, and median magnesium levels between the dementia and control groups. However, there were marginally but significantly more cases with low magnesium levels among dementia patients than among controls: A total of 9.4% of tests done in patients with dementia and 7.81% done in non-dementia subjects were hypomagnesemic (p <  0.00001).

Conclusion

Despite similar means and medians of serum magnesium in dementia and controls, the proportion of lower than normal magnesium test results was slightly higher among dementia patients. It is possible that patients with dementia have more episodes of hypomagnesemia than controls, despite similar overall mean levels of magnesium.

The Association Between the Concentration of Serum Magnesium and Postmenopausal Osteoporosis

Background: Osteoporosis is the most common and widespread chronic skeletal metabolic disease in the world and can lead to catastrophic fractures. Therefore, it is important to look for factors that can be modified or controlled to prevent osteoporosis. Although serum Mg is believed to be associated with osteoporosis in many individuals, there are conflicting reports on the association between serum Mg and osteoporosis. Therefore, this meta-analyses aimed to explore the association between the concentration of serum Mg and osteoporosis as well as that between the concentration of serum Mg and osteopenia.

Methods: Articles were searched in PubMed. We also reviewed the reference lists of the relevant publications and reviews as of December 2019. Finally, 11 eligible studies involving 2,776 postmenopausal women were selected. We performed subgroup analysis, and publication bias was assessed.

Results: According to the forest plot analysis, postmenopausal women with osteoporosis had a lower concentration of serum Mg than normal controls [standardized mean difference (SMD) = −0.56, 95% confidence interval (CI) = −1.02 to −0.09]. However, this result was not applicable to those with osteopenia (SMD = −0.30, 95% CI = −0.69 to 0.09). The subgroup analysis by geographical location found a similar pattern in European postmenopausal women with osteoporosis (SMD = −0.73, 95% CI = −1.322 to −0.143), but not in Asian (SMD = −0.007, 95% CI = −0.381 to 0.394). The subgroup analysis by site of bone mineral density (BMD) showed the serum Mg concentration of postmenopausal women with osteoporosis (BMD of femur) was lower than in healthy controls (SMD = −0.44, 95% CI = −0.77 to −0.12), and BMD of the spine group had the same conclusion (SMD = −0.78, 95% CI = −1.36 to −0.19). Besides, the serum Mg concentration of postmenopausal women with osteoporosis was lower than that of the normal bone mass group in the studies those included more than 50 postmenopausal women with osteoporosis (SMD = −0.57, 95% CI = −1.04 to −0.11). We also found postmenopausal women under the age of 60 with osteoporosis had a lower concentration of serum Mg than the healthy controls (SMD = −0.61, 95% CI = −1.09 to −0.13).

Conclusion: Postmenopausal women with osteoporosis have a lower concentration of serum Mg. However, the association between the concentration of serum Mg and osteopenia needs further confirmation.

Variations in Magnesium Concentration Are Associated with Increased Mortality: Study in an Unselected Population of Hospitalized Patients

Dysmagnesemia is a serious disturbance of microelement homeostasis. The aim of this study was to analyze the distribution of serum magnesium concentrations in hospitalized patients according to gender, age, and result of hospitalization. The study was conducted from February 2018 to January 2019 at the Central Clinical Hospital in Warsaw. Laboratory test results from 20,438 patients were included in this retrospective analysis. When a lower reference value 0.65 mmol/L was applied, hypermagnesemia occurred in 196 patients (1%), hypomagnesemia in 1505 patients (7%), and normomagnesemia in 18,711 patients (92%). At a lower reference value of 0.75 mmol/L, hypomagnesemia was found in 25% and normomagnesemia in 74% of patients. At a lower reference value of 0.85 mmol/L, hypomagnesemia was found in 60% and normomagnesemia in 39% of patients. Either hypo- or hyper-magnesemia was associated with increased risk of in-hospital mortality. This risk is the highest in patients with hypermagnesemia (40.1% of deaths), but also increases inversely with magnesium concentration below 0.85 mmol/L. Serum magnesium concentration was not gender-dependent, and there was a slight positive correlation with age (p < 0.0001, r = 0.07). Large fluctuations in serum magnesium level were associated with increased mortality (p = 0.0017). The results indicate that dysmagnesemia is associated with severe diseases and generally severe conditions. To avoid misdiagnosis, an increase of a lower cut-off for serum magnesium concentration to at least 0.75 mmol/L is suggested.

Insulin Resistance and Serum Magnesium Concentrations among Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) affects ∼1 in 10 women worldwide. Hypomagnesemia may worsen insulin resistance (IR) due to the role magnesium (Mg) plays in glucose metabolism. This review explores the relation between serum Mg and IR among women with PCOS. A review of primary research focusing on both serum Mg and women with PCOS was conducted from 2011 to 2019. Studies reviewed included human subjects, written in the English language, and limited to community-dwelling women aged ≥18 y. A total of 7 articles were reviewed. The findings from 4 epidemiological analytic studies evaluating serum Mg status suggest there may be a relation between serum Mg concentrations and IR among women with PCOS. However, among the 3 experimental trials, Mg supplementation inconsistently impacted IR among women with PCOS. Women with PCOS are more likely to underconsume Mg-rich foods and have a greater likelihood of lower serum Mg concentrations. Although it remains unclear if dietary Mg and/or supplementation should be a nutritional strategy for all women with PCOS, current research indicates an association between adequate Mg status and improved IR. Further research evaluating dietary interventions and supplementation is warranted.

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.

Prospective Association of Serum and Dietary Magnesium with Colorectal Cancer Incidence

BACKGROUND

Laboratory and epidemiologic research suggests a protective role of magnesium in colorectal cancer development. We estimated the associations of serum and dietary magnesium with colorectal cancer incidence in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS

Serum magnesium concentration was measured in blood collected twice (1987-1989 and 1990-1992) and averaged. Dietary magnesium was assessed by food-frequency questionnaire administered twice (1987-1989 and 1993-1995) and averaged. For both dietary and serum magnesium, the averaged measures were categorized into quintiles for analysis. Analyses included 315 colorectal cancer cases among 13,009 participants for serum magnesium (followed for a median of 20.4 years), and 256 cases among 10,971 participants for dietary magnesium (followed for a median of 17.5 years). Cox proportional hazards regression was used to calculate multivariable-adjusted HRs and 95% confidence intervals (CI).

RESULTS

Multivariable-adjusted HRs (95% CI) of colorectal cancer for the highest four quintiles compared with the first quintile of serum magnesium were as follows: Q2: 0.70 (0.49-0.99); Q3: 0.68 (0.47-1.00); Q4: 0.87 (0.62-1.21); and Q5: 0.79 (0.57-1.11; P trend = 0.04). An inverse association was present in females (HR for Q5 vs. Q1: 0.59, 95% CI: 0.36-0.98, P trend = 0.01), but not males (HR for Q5 vs. Q1: 1.10, 95% CI: 0.67-1.79, P trend = 0.92; P interaction = 0.34). Dietary magnesium was not statistically significantly associated with colorectal cancer risk.

CONCLUSIONS

Our study found a higher risk of colorectal cancer with lower serum magnesium among females, but not males.

IMPACT

If our findings are confirmed, maintaining adequate serum magnesium levels may be important for colorectal cancer prevention.

The relationship between serum magnesium levels and mortality in non-diabetic hemodialysis patients: A 10-year follow-up study

Introduction Recently, although there are many reports showing that serum magnesium concentration is a predictor of mortality in dialysis patients, the observation periods of those reports were of short duration, typically around 12 months. Thus, we investigated this relationship over a longer follow-up period. Methods This retrospective, observational study included a total of 83 non-diabetic hemodialysis patients. The follow-up period was 120 months. Patients were divided into two groups, those with serum magnesium ≥2.5 mg/dL (Mg ≥2.5 mg/dL group) and serum magnesium <2.5 mg/dL (Mg <2.5 mg/dL group), and Kaplan-Meier analysis and Cox proportional hazards analysis were conducted. In addition to the above analysis, single and multiple regression analysis were performed at baseline to reveal the relationship between serum magnesium and clinical parameters. Findings During the follow-up period, 31 out of 83 patients died. Kaplan-Meier analysis showed a significantly higher incidence of death in the Mg <2.5 mg/dL group (log-rank test 4.951, P = 0.026). Multivariate Cox proportional hazards analysis showed a 62% decreased risk of mortality in the Mg ≥2.5 mg/dL group compared to the Mg <2.5 mg/dL group after adjustment for several confounding factors. Simple correlation coefficient analysis showed positive correlations of serum magnesium levels with serum creatinine, phosphorus, high-density lipoprotein, ankle-brachial index and KT/V, and a negative correlation with age. Multiple linear regression analysis showed that the ankle-brachial index was the only parameter that had a positive and significant correlation with the serum magnesium level. Conclusion Our study demonstrated that higher serum magnesium levels were associated with improved survival in non-diabetic hemodialysis patients.

[Relationship between serum magnesium concentration and obesity in Chinese adults]

OBJECTIVE

To explore the relationship between concentration of serum magnesium with overweight/obesity and abdominal obesity in Chinese adults.

METHODS

Data from China Health and Nutrition Survey investigated in 2009 was analyzed. Rank correlation analysis, univariate analysis and binary Logistic regression analysis were performed to analyze influence of serum magnesium concentrations, regions and gender on the prevalence of overweight/obesity and abdominal obesity.

RESULTS

The prevalence of overweight/obesity was 40. 2%. The concentration of serum magnesium in people withoverweight/obesity was higher than that in people with non-overweight/obesity( 0. 95 mmol/L vs. 0. 93 mmol/L, t = 7. 021, P < 0. 001). The prevalence of overweight/obesity was 33. 2%. The concentration of serum magnesium in people with abdominal obesity was higher than that in people with non-abdominal obesity( 0. 95 mmol/L vs. 0. 93 mmol/L, t = 5. 712, P < 0. 001). The serum magnesium concentration, prevalence of overweight/obesity and abdominal obesity were higher in magnesium-rich area than in the nonmagnesium-rich areas, which showed significant differences between two groups( serum magnesium: t = 8. 012, P < 0. 001; overweight/obesity: χ~2= 138. 252, P < 0. 001;abdominal obesity: χ~2= 134. 999, P < 0. 001). The rank correlation coefficients between serum magnesium concentration and prevalence of overweight/obesity and abdominal obesity were 0. 952 and 0. 796 in male, and 0. 794 and 0. 903 in female, respectively. Serum magnesium concentration was divided into four grades according to quartiles. The risk of overweight/obesity increased by 1. 207 times( 95% CI 1. 138-1. 281) when the serum magnesium increased a level, and the risk of abdominal obesity increased by 1. 187 times( 95% CI 1. 114-1. 266).

CONCLUSION

Higher serum magnesium concentration may be a risk factor for overweight/obesity and abdominal obesity. Serum magnesium concentration is moderately and even highly correlated with prevalence of obesity, and there is a gender difference in this relationship.

Serum Magnesium as a Marker of Neurological Outcome in Severe Traumatic Brain Injury Patients

Hypomagnesemia is postulated as one of the important determinants of outcome following traumatic brain injury (TBI) through its effect on secondary injuries to neurons.

A retrospective evaluation of furosemide and mannitol for prevention of cisplatin-induced nephrotoxicity

WHAT IS KNOWN AND OBJECTIVE

Nephrotoxicity is a recognized side effect of cisplatin chemotherapy. However, the optimal strategy for preventing cisplatin-induced nephrotoxicity, if any, remains unclear. The primary objective for this study was to determine whether mannitol or furosemide provides better nephroprotection when administered with hydration prior to weekly, low-dose cisplatin concurrently with whole pelvic radiotherapy.

METHODS

Clinical data were abstracted from all women who underwent chemoradiation for FIGO IB2-IVA cervical cancer at a regional safety net health system between January 2009 and December 2014. Creatinine clearance was estimated using the IDMS-traceable MDRD Study Equation. Descriptive statistics were used to summarize patient demographics. Cox proportional hazard models were used to identify factors associated with hypomagnesemia and survival.

RESULTS AND DISCUSSION

A total of 133 women received 656 weekly doses of single-agent cisplatin (40 mg/m² ) concomitant with whole pelvic radiation. Furosemide (20 mg) was administered intravenously prior to 341 cisplatin doses, whereas mannitol (24 g) was administered prior to 315 doses. Significant magnesium wasting was observed after the second weekly cisplatin infusion regardless of whether furosemide or mannitol was utilized. Repetitive low-dose cisplatin infusion had no impact on measured levels of serum creatinine or estimated glomerular filtration rate. Prior history of hypertension, diabetes mellitus, hepatitis C infection and acute gastrointestinal toxicity were each associated with early onset of hypomagnesemia.

WHAT IS NEW AND CONCLUSIONS

Repetitive administration of low-dose cisplatin concurrent with whole pelvic radiation is associated with magnesium wasting. However, choice of diuretic with pretreatment hydration had no significant impact on the severity of this adverse effect.

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

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

Clinical pharmacokinetic properties of magnesium sulphate in women with pre-eclampsia and eclampsia

BACKGROUND

The pharmacokinetic basis of magnesium sulphate (MgSO4 ) dosing regimens for eclampsia prophylaxis and treatment is not clearly established.

OBJECTIVES

To review available data on clinical pharmacokinetic properties of MgSO4 when used for women with pre-eclampsia and/or eclampsia.

SEARCH STRATEGY

MEDLINE, EMBASE, CINAHL, POPLINE, Global Health Library and reference lists of eligible studies.

SELECTION CRITERIA

All study types investigating pharmacokinetic properties of MgSO4 in women with pre-eclampsia and/or eclampsia.

DATA COLLECTION AND ANALYSIS

Two authors extracted data on basic pharmacokinetic parameters reflecting the different aspects of absorption, bioavailability, distribution and excretion of MgSO4 according to identified dosing regimens.

MAIN RESULTS

Twenty-eight studies investigating pharmacokinetic properties of 17 MgSO4 regimens met our inclusion criteria. Most women (91.5%) in the studies had pre-eclampsia. Baseline serum magnesium concentrations were consistently <1 mmol/l across studies. Intravenous loading dose between 4 and 6 g was associated with a doubling of this baseline concentration half an hour after injection. Maintenance infusion of 1 g/hour consistently produced concentrations well below 2 mmol/l, whereas maintenance infusion at 2 g/hour and the Pritchard intramuscular regimen had higher but inconsistent probability of producing concentrations between 2 and 3 mmol/l. Volume of distribution of magnesium varied (13.65-49.00 l) but the plasma clearance was fairly similar (4.28-5.00 l/hour) across populations.

CONCLUSION

The profiles of Zuspan and Pritchard regimens indicate that the minimum effective serum magnesium concentration for eclampsia prophylaxis is lower than the generally accepted level. Exposure-response studies to identify effective alternative dosing regimens should target concentrations achievable by these standard regimens.

TWEETABLE ABSTRACT

Minimum effective serum magnesium concentration for eclampsia prophylaxis is lower than the generally accepted therapeutic level.

Polymorphism in Cytochrome P450 2D6, Glutathione S-Transferases Pi 1 Genes, and Organochlorine Pesticides in Alzheimer Disease: A Case-Control Study in North Indian Population

OBJECTIVES

It has been assumed that the association between Alzheimer disease (AD) and pesticides may be stronger among genetically susceptible individuals. The aim of the study was to examine the genetic polymorphism in cytochrome P450 2D6 (CYP2D6) and glutathione S-transferases pi 1 (GSTP1) with respect to organochlorine pesticides (OCPs) and metals in AD.

METHODS

This study included 100 patients with AD and 100 age-matched controls. The genetic polymorphisms were analyzed by restriction fragment length polymorphism. The OCPs and serum metal levels were determined using gas chromatography and an autoanalyzer, respectively.

RESULTS

We found a statistically significant association between AD and high levels of β-hexachlorocyclohexane (β-HCH; odds ratio [OR] = 2.064, 95% confidence intervals [95% CIs] = 1.373-3.102, dieldrin [OR = 2.086, 95% CI = 1.224-3.555], and copper [OR = 1.038, 95% CI = 1.012-1.064). The significant low level of magnesium (OR = 0.151, 95% CI = 0.047-0.489) even appears to have a protective role against AD. The GSTP1*B (P = .009) and GSTP1*C (P = .011) allelic variants were associated with increase in AD risk.

CONCLUSION

This study demonstrates that the GSTP1*B and *C allelic variants may be considered a candidate gene for AD. It can be suggested that although CYP2D6*4 polymorphism is not a risk of AD, the CYP2D6*4 and GSTP1 polymorphism may interact with β-HCH, dieldrin, and copper to influence the risk of AD.

Magnesium and selenium in diabetics with peripheral artery disease of the lower limbs

BACKGROUND AND AIMS

Knowing that diabetes mellitus (DM) often leads to cardiovascular injury such as peripheral artery disease (PAD) of the lower limbs and that some microelements like magnesium (Mg) and Selenium (Se) might be involved in the alterations entailed by these complications, we aimed to investigate the behavior of those microelements in these diseases.

METHODS

We studied 114 patients with type 2 DM, treated not with insulin but only by diet or oral antidiabetics, mean aged 56.6 having a mean duration of the diabetes of 14.5 years, mostly men (80), 64 of them (40 men) having also PAD stage 2 without severe complications. We had a control group of 40 similarly-aged subjects without DM or PAD. The measurements were performed on a Konelab 30I device and serum selenium was quantified by atomic absorption spectroscopy. All patients underwent clinical, paraclinical and arterial Doppler echography for establishing the diagnosis of PAD.

RESULTS

The results for controls were 2.2±0.4 mg/dl for Mg, 130±6 μg/dl for Se; diabetics had 1.68±0.4 mg/dl Mg, 88±6 μg/dl Se; diabetics with PAD had significantly lower levels: 1.36±0.6 mg/dl Mg, 66±6 μg/dl Se (p<0.05). Age inversely correlated with the values of both microelements especially in women. Mixed dysipidemia, present in DM, correlated with PAD. Blood pressure also inversely correlated with Mg and Se. Coronary heart disease (ischemia) linked to lower blood values of Mg and Se. Left Ventricle Hypertrophy (as proved by echography) also correlated to lower blood values of Mg and Se, as did glycated hemoglobin (HbA1c).

CONCLUSION

We may conclude that in DM there is a Mg deficit which becomes significant in DZ+PAD especially in forms with high blood pressure (HBP), severe dyslipidemia and in the presence of early microvascular complications, our paper suggesting the opportunity of a substitutive treatment with Mg and Se in selected cases.

Is hypomagnesaemia a coronary risk factor among Indians with coronary artery disease?

Introduction:

Magnesium is an essential element that has numerous biological functions in the cardiovascular system. Hence, three hundred patients with known cardiovascular disease above the age of 25 years were studied to evaluate association between dietary and serum magnesium with cardiovascular risk factors.

Materials and Methods:

Patients were divided into three groups according to serum magnesium levels; ≤1.6 (Group 1), >1.6-2.6 (Group 2) and: >2.6 mg/dl (Group 3), and into two groups according to dietary magnesium intake; ≤350 mg/day (Group 1) and >350 mg/day (Group 2), respectively.

Results:

Mean age of patients was 60.97 ± 12.5 years. Total cholesterol, triglycerides, VLDL, and LDL were significantly higher and HDL cholesterol significantly lower in group 1 when compared with group 2 and group 3. Diabetes, dyslipidemia, and hypertension were negatively correlated with serum magnesium levels; which were maintained even after adjustment with age, sex, and anthropometric parameters in multiple regression analysis. Similar observations were observed in dietary magnesium intake except LDL and total cholesterol. Dietary magnesium was positively correlated with serum magnesium.

Conclusions:

Hypomagnesaemia and low dietary intake of magnesium are strongly related to cardiovascular risk factors among known subjects with coronary artery disease. Hence, magnesium supplementation may help in reducing cardiovascular disease.

Serum magnesium and stable asthma: Is there a link?

Background:

Although magnesium is used through intravenous and inhalation route in the management of asthma, actual prevalence of hypomagnesemia in asthma is not known. We conducted this study: 1) to detect the prevalence of hypomagnesemia in stable asthma and 2) to assess the significance of hypomagnesemia in these patients.

Design:

Prospective clinical study.

Setting:

Department of Respiratory Medicine, Calcutta National Medical College, Kolkata.

Period of Study:

Four months from January, 2007, to April, 2007.

Materials and Methods:

Fifty patients attending outpatients department of respiratory medicine with stable asthma were randomly selected. They were assessed clinically and their serum magnesium levels were measured. This was compared with the serum magnesium values of 45 nonasthmatic healthy controls.

Results:

Out of 50 patients, 14 had hypomagnesemia. Possible relationship of hypomagnesemia with tachycardia, tachypnoea, severity of asthma, medication use, and previous and future exacerbations were analyzed.

Conclusion:

There was statistically significant association of hypomagnesemia with tachypnoea, severe asthma, use of long-acting β-agonist, inhaled corticosteroids, theophylline, use of ≥ 3 medications, previous and future exacerbations but not with tachycardia or use of short-acting β₂ -agonist or montelukast.

Metabolic and clinical effects of oral magnesium supplementation in furosemide-treated patients with severe congestive heart failure

BACKGROUND

Magnesium depletion and hypomagnesemia are common among furosemide-treated patients with chronic congestive heart failure.

HYPOTHESIS

This investigation evaluated clinical and metabolic effects of oral magnesium supplementation.

METHODS

Ten patients with severe congestive heart failure maintained on high dose furosemide (> or = 80 mg/day) received a supplement of oral magnesium citrate 300 mg/daily for 30 days. Clinical parameters were followed, and peripheral blood mononuclear cell magnesium and zinc content, serum and urine magnesium, potassium, zinc, calcium, phosphorus, and creatinine were assessed.

RESULTS

Peripheral blood mononuclear cell magnesium content and serum potassium rose significantly at the end of the study (2.09 +/- 1.89 to 3.99 +/- 2.26 micrograms/mg cell protein, p < 0.05, and 4.17 +/- 0.38 to 4.39 +/- 0.27 mEq/l, p < 0.05, respectively), while the other parameters remained unchanged.

CONCLUSION

In some of these patients, oral magnesium supplementation is effective in achieving substantial increments in intracellular magnesium and serum potassium which, in turn, may have cardioprotective effects.