Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis.

Magnesium (Mg) plays a key role in neurological functioning and manifestations. However, the evidence from randomized controlled trials (RCTs) and cohorts on Mg and cognitive health among adults has not been systematically reviewed. We aimed to examine the associations of various Mg forms (supplements, dietary intake, and biomarkers) with cognitive outcomes by summarizing evidence from RCTs and cohorts. PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched for relevant peer-reviewed articles published up to May 3, 2024. Three random-effects models were performed, when appropriate, to evaluate the relationship between Mg and cognitive outcomes: 1) linear meta-regression, 2) non-linear (quadratic) meta-regression, and 3) meta-analysis using Mg variables categorized based on pre-existing recommendations. Three RCTs and 12 cohort studies were included in this systematic review. Evidence from the limited numbers of RCTs was insufficient to draw conclusions on the effects of Mg supplements. Cohort studies showed inconsistent dose-response relationships between dietary Mg and cognitive disorders, with high heterogeneity across populations. However, consistent U-shape associations of serum Mg with all-cause dementia and cognitive impairment were found in cohorts, suggesting an optimal serum Mg concentration around 0.85 mmol/L. This non-linear association was detected in meta-regression (Pquadratic = 0.003) and in meta-analysis based on the reference interval of serum Mg (0.75-0.95 mmol/L) [<0.75 compared with 0.85 mmol/L: pooled hazard ratio (HR) = 1.43; 95% confidence interval (CI) = 1.05, 1.93; >0.95 compared with 0.85 mmol/L: pooled HR = 1.30; 95% CI = 1.03, 1.64]. More evidence from RCTs and cohorts is warranted. Future cohort studies should evaluate various Mg biomarkers and collect repeated measurements of Mg intake over time, considering different sources (diet or supplements) and factors affecting absorption (e.g., calcium-to-Mg intake ratio). This systematic review was pre-registered in PROSPERO (CRD42023423663).

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.

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: ß (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [ß (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: ß (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.

Nomogram for predicting early hypophosphatemia in term infants.

BACKGROUND: Physiological processes rely on phosphate, which is an essential component of adenosine triphosphate (ATP). Hypophosphatasia can affect nearly every organ system in the body. It is crucial to monitor newborns with risk factors for hypophosphatemia and provide them with the proper supplements. We aimed to evaluate the risk factors and develop a nomogram for early hypophosphatemia in term infants. METHODS: We conducted a retrospective study involving 416 term infants measured serum phosphorus within three days of birth. The study included 82 term infants with hypophosphatemia (HP group) and 334 term infants without hypophosphatemia (NHP group). We collected data on the characteristics of mothers, newborn babies, and childbirth. Furthermore, univariate and multivariate logistic regression analyses were performed to identify independent risk factors for hypophosphatemia in term infants, and a nomogram was developed and validated based on the final independent risk factors. RESULTS: According to our analysis, the multivariate logistic regression analysis showed that male, maternal diabetes, cesarean delivery, lower serum magnesium, and lower birth weight were independent risk factors for early hypophosphatemia in term infants. In addition, the C-index of the developed nomogram was 0.732 (95% CI = 0.668-0.796). Moreover, the calibration curve indicated good consistency between the hypophosphatemia diagnosis and the predicted probability, and a decision curve analysis (DCA) confirmed the clinical utility of the nomogram. CONCLUSIONS: The analysis revealed that we successfully developed and validated a nomogram for predicting early hypophosphatemia in term infants.

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.

Impact of Dysmagnesemia on Atrial Fibrillation in Maintenance Hemodialysis Patients: A Nationwide Study.

INTRODUCTION: The dose-response relationship between serum magnesium (sMg) and atrial fibrillation (AF) and the contribution of dysmagnesemia to AF among hemodialysis patients remain unknown. Hence, we examined the dose-response correlation between sMg and AF and estimated the extent of the contribution of dysmagnesemia to AF in this population. METHODS: This was a nationwide cross-sectional study on the Japanese Society for Dialysis Therapy registry, also known as Japanese Renal Data Registry (JRDR), encompassing a nationwide population of dialysis centers, as of the end of 2019. Eligible participants were adult patients undergoing hemodialysis three times per week. The main exposure was sMg, categorized into seven categories (≤1.5, >1.5-≤2, >2-≤2.5, >2.5-≤3, >3-≤3.5, >3.5-≤4, and ≥4.0 mg/dL). The outcome was AF reported by dialysis facilities. The independent contribution to AF was assessed via logistic regression to generate population-attributable fractions, assuming a causal relationship between sMg and AF. RESULTS: Total 165,926 patients from 2,549 facilities were investigated. AF prevalence was 7.9%. Compared with the reference (>2.5-≤3 mg/dL), lower sMg was associated with increased AF (adjusted odds ratios (ORs) (95% confidence interval, CI) of 1.49 (1.19-1.85), 1.24 (1.17-1.32), and 1.11 (1.06-1.16) for sMg of ≤1.5, >1.5-≤2.0, and >2.0-≤2.5 mg/dL categories, respectively). Elevated sMg was associated with fewer AF (adjusted OR 0.87 [95% CI, 0.79-0.96] for sMg of >3.0-≤3.5 mg/dL). The adjusted population-attributable fraction of lower sMg and higher and lower sMg for AF was 7.4% and 6.9%, respectively. An association did indeed exist between lower sMg and AF, with the lowest percentages of AF at sMg levels above the reference range for the general population. CONCLUSION: Dysmagnesemia may be an important contributor to AF among adult hemodialysis patients. Further, longitudinal studies are warranted to determine whether sMg correction reduces the AF incidence.

The association between serum magnesium and chronic kidney disease in Chinese adults: a cross-sectional study.

BACKGROUND: Magnesium (Mg) is both an essential macro-element and a known catalyst, and it plays a vital role in various physiological activities and mechanisms in relation to chronic kidney disease (CKD). However, epidemiological evidence involving this is limited and not entirely consistent. This study aims to explore the association of serum Mg concentrations with the risk of CKD among general Chinese adults. METHODS: A total of 8,277 Chinese adults were included in the wave of 2009 from the China Health and Nutrition Survey (CHNS). The primary outcome was the risk of CKD, which was defined as the estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. Multivariable logistic regression model was used to examine the relationship of serum Mg concentrations with the risk of CKD. RESULTS: Included were 8,277 individuals, with an overall CKD prevalence of 11.8% (n = 977). Compared with the first quartile of serum Mg, the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for participants in the second, third, and fourth quartiles of serum Mg were 0.74 (0.58, 0.93), 0.87 (0.69, 1.11) and 1.29 (1.03, 1.61), respectively. Similar results were observed in our several sensitivity analyses. Restricted cubic spline analysis demonstrated a nonlinear (similar "J"-shaped) association between serum Mg concentrations and the risk of CKD (Pnonlinearity <0.001), with a threshold at around a serum Mg value of 2.2 mg/dL. CONCLUSIONS: Our results suggested a similar "J"-shaped association between serum Mg concentration and the risk of CKD among Chinese adults. Further large prospective studies are needed to verify these findings.

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.

Serum Magnesium Level as a Biomarker to Predict the Risk of Labor Epidural Anesthesia Associated Fever.

Objective: Excessive pain will have adverse effects on the mother and fetus. Labor epidural analgesia greatly reduces the pain, which is widely carried out abroad. Labor epidural anesthesia-associated fever (LEAF) is the biggest problem for labor epidural anesthesia. This study aimed to evaluate the clinical value of serum magnesium levels to predict the LEAF. Methods: Overall 528 singleton term-pregnant women who underwent labor epidural anesthesia in Fujian Provincial Maternity and Children's Health Hospital, affiliated hospital of Fujian Medical University from January 2019 to June 2019, were analyzed retrospectively. The serum magnesium level was detected using venous blood samples. The relationship between the serum magnesium level and LEAF was interpreted, and the optimal cut-off values of the serum magnesium level to predict LEAF were calculated. Results: Overall, 65 (12.30%) participants had LEAF. And a higher rate of the bulging membrane, gestational hypertension, neonatal intensive care unit (NICU) admission, and the different mode of delivery was significantly associated with LEAF. Also, the serum magnesium level demonstrated higher significantly in presence of LEAF than absence (P<0.05). What is more, it indicated that the area under the receiver operating characteristic curve (AUC) for the serum magnesium level was 0.825, and an optimal cut-off of the serum magnesium level was 0.855 mg/dl. Furthermore, it demonstrated that the serum magnesium level had the highest OR (OR= 7.49; 95% CI (4.58-14.35)) (P<0.001). The bulging membrane is an independent risk factor presence of LEAF (OR = 1.55; 95% CI (1.01-2.43)) (P=0.038). Conclusion: This study demonstrated that the baseline of serum magnesium can provide a suitable biomarker to predict LEAF. It can help to provide a useful target for LEAF treatment and enhance surveillance before fever.

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.

Study Based on the Alliance Between Serum Magnesium Levels and Preterm Labor: An Inclusive Review.

Preterm labor, regarded as the onset of labor before 37 weeks of gestation, is a highly prevalent issue in obstetrics with repercussions for neonatal health. This review article presents an in-depth analysis of the alliance between serum magnesium levels and preterm labor. The review explores the physiological roles of magnesium right through pregnancy, including its significance for energy metabolism, smooth muscle contraction, deoxyribonucleic acid (DNA), and protein synthesis. It addresses cellular transport and the homeostasis of magnesium. The pathophysiological processes encompassing inflammation, oxidative stress, calcium regulation, smooth muscle contractility, and neuroendocrine pathways are investigated. The review evaluates epidemiological studies investigating the alliance between serum magnesium levels and preterm labor. The review incorporates an assortment of study varieties, such as observational studies, case-control studies, prospective cohort studies, and meta-analyses. In the course of reviewing the prognostic relevance of serum magnesium levels in premature labor, therapeutic implications involving diagnostic precision, prognostic significance, and therapeutic response assessment have additionally been addressed. Therapeutic interventions targeting magnesium levels, such as magnesium supplementation, tocolytic therapy, and the role of magnesium in antenatal corticosteroid administration, are explored. This review provides an in-depth evaluation of the correlation between serum magnesium levels and preterm labor, stressing its therapeutic significance and repercussions for future research and treatment strategies.

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.

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.

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.

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.

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.

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.

Higher Serum Magnesium Is a Survival Advantage in Maintenance Hemodialysis Patients.

INTRODUCTION: Elevated serum magnesium is common and associated with survival in maintenance hemodialysis (MHD) patients by observational studies. However, the results of these studies were underpowered and inconclusive. This work was designed to explore the predictive value of serum magnesium on the mortality of patients with MHD. METHODS: We retrospectively analyzed mortality rates in 267 patients with MHD. The collected parameters included anthropometrics and laboratory parameters. Serum magnesium included baseline serum magnesium (BS-Mg) and average serum magnesium (AS-Mg). Receiver operator characteristic (ROC) curves were drawn, and multivariate Cox proportional hazards models were applied to identify the predictive value of serum magnesium on patient mortality. RESULTS: During the 64-month follow-up period, 121 (45.3%) all-cause and 75 (28.1%) cardiovascular disease (CVD) deaths were recorded. The predictability of death of AS-Mg yielded results similar to those of serum albumin, secondary only to age, and superior to those of the high-sensitivity C-reactive protein (Hs-CRP), BS-Mg, by ROC curves. There were significant differences in all-cause and CVD mortality between the four groups (by quartile). Kaplan-Meier survival analyses revealed that the lowest 25th percentile had the poorest prognosis for both all-cause mortality (p < 0.001) and CVD mortality (p = 0.011). Finally, multivariate Cox proportional hazards models showed that increased age, increased Hs-CRP, decreased serum albumin, and AS-Mg were independent predictors of all-cause and CVD mortality. The hazard ratios of AS-Mg (per 0.01 mmol/L) were 0.925 (95% confidence interval, 0.884-0.968, p = 0.001) for all-cause mortality and 0.976 (95% confidence interval, 0.954-0.999, p = 0.040) for CVD mortality. CONCLUSION: AS-Mg was a good indicator for assessing all-cause and CVD mortality in patients with MHD in China. Higher serum magnesium had a survival advantage. Further studies with larger sample sizes should be needed to clarify the best reference value for maximizing the beneficial effects of magnesium.