Serum magnesium, mortality, and cardiovascular disease in chronic kidney disease and end-stage renal disease patients: a systematic review and meta-analysis

Association between magnesium depletion score and stroke in US adults with chronic kidney disease: A population-based study

BACKGROUND

Magnesium ion metabolism disorder is pervasive in the chronic kidney disease population, which is affected by many factors. Magnesium ion plays an important role in maintaining vascular functional integrity.. The Magnesium Depletion Score (MDS), serving as a novel metric for the assessment of magnesium deficiency, has not been thoroughly investigated for its association with stroke in patients with chronic kidney disease (CKD). Therefore, this study aims to explore the relationship between the MDS index and stroke in CKD patients.

METHODS

We conducted a cross-sectional population-based study using data from the National Health and Nutrition Examination Survey 2009-2016 to explore the impact of MDS on the stroke outcome of CKD patients. The primary outcome was the risk of stroke in CKD patients. Sample-weighted multivariate logistic regression was used in our analysis.

RESULTS

In this study of 3536 CKD patients from the database, we found an 8.6 % prevalence of stroke with higher stroke risk in older individuals and males. Lower dietary magnesium intake and higher MDS scores were significantly associated with stroke risk. Multivariate logistic regression analysis revealed a dose-dependent relationship between MDS scores and stroke likelihood, independent of demographic and clinical factors. Subgroup analysis confirmed these findings, particularly in those with hypertension, diabetes, and obesity, without significant interactions (all p > 0.05).

CONCLUSION

Magnesium depletion is independently associated with a heightened stroke risk in chronic kidney disease patients.

Association between magnesium, erythropoietin resistance and mortality: the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS)

Background

Limited data are now available to evaluate the relationship between serum magnesium level, anemia and mortality in the dialysis population.

Methods

Using data from the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) phases 5 and 6, we analyzed the association between serum magnesium (s-Mg) levels and the erythropoiesis-stimulating agents resistance index (ERI) as the primary outcome. To estimate the longitudinal relationship, a mixed-effect model was used with ERI at each 4-month period as the dependent variable and quintiles of s-Mg at the previous 4-month period as the independent variable. We also examined incidence of infectious events, and the all-cause and cardiovascular disease (CVD)-related deaths as secondary outcomes by Cox regression with quintiles of s-Mg at baseline.

Results

Of the 4776 participants in J-DOPPS, 1650 were included in the analysis. The median of s-Mg at baseline was 2.5 mg/dL. A significant linear association of s-Mg with ERI (P for trend <.001) was revealed. Low and high s-Mg levels were not associated with the clinical outcomes of interest, except for the highest quintile of s-Mg being significantly associated with lower incidence of all-cause mortality and CVD-related deaths compared with the middle (reference) quintile.

Conclusions

We observed that lower s-Mg levels subsequently induced higher ERI and that mild higher s-Mg levels were possibly associated with good rather than poor outcomes in Japanese hemodialysis patients. Adjustment of s-Mg levels may be proposed as a new strategy at a low cost and risk to reduce the risk of premature mortality.

Serum Magnesium Levels in Patients with Chronic Kidney Disease: Is There a Relationship with Inflammation Status?

BACKGROUND

Magnesium (Mg2+) is a fundamental mineral that maintains cellular function, and low levels may be linked to inflammation in patients with chronic kidney disease (CKD). This cross-sectional study evaluated the correlation between serum Mg2+ levels and the inflammatory status in patients undergoing dialysis.

METHODS

Two hundred patients with CKD [150 undergoing hemodialysis (HD), 50 (18) years; BMI 24 (4.8) kg/m²; and 50 patients on peritoneal dialysis (PD), 54 (17.7) years; BMI, 27.5 (7.3) kg/m²] were included. Serum Mg2+ levels were evaluated using a colourimetric test and commercial kit. Inflammatory markers were assessed by ELISA and multiplex bead-based assay. Lipid peroxidation was evaluated using thiobarbituric acid-reactive substances.

RESULTS

The median serum Mg2+ levels were 2.3 (0.5) mg/dL, and 21% of patients presented Mg2+ deficiency (< 2.07 mg/dL or 0.85 mmol/L). We found no difference in Mg2+ serum levels between the two groups. A significant negative correlation was observed between serum Mg2+ levels and plasma hs-CRP (r =-0.17, p = 0.01), IL-8 (r =-0.35, p = 0.01), and MCP-1 (r =-0.31, p = 0.03) levels.

CONCLUSION

Mg2+ serum levels were negatively correlated with inflammatory status in patients with CKD on dialysis.

Magnesium and Vascular Calcification in Chronic Kidney Disease: Current Insights

Magnesium (Mg) plays crucial roles in multiple essential biological processes. As the kidneys are the primary organ responsible for maintaining the blood concentration of Mg, people with chronic kidney disease (CKD) may develop disturbances in Mg. While both hyper- and hypomagnesemia may lead to adverse effects, the consequences associated with hypomagnesemia are often more severe and lasting. Importantly, observational studies have shown that CKD patients with hypomagnesemia have greater vascular calcification. Vascular calcification is accelerated and contributes to a high mortality rate in the CKD population. Both in vitro and animal studies have demonstrated that Mg protects against vascular calcification via several potential mechanisms, such as inhibiting the formation of both hydroxyapatite and pathogenic calciprotein particles as well as limiting osteogenic differentiation, a process in which vascular smooth muscle cells in the media layer of the arteries transform into bone-like cells. These preclinical findings have led to several important clinical trials that have investigated the effects of Mg supplementation on vascular calcification in people with CKD. Interestingly, two major clinical studies produced contradictory findings, resulting in a state of equipoise. This narrative review provides an overview of our current knowledge in the renal handling of Mg in health and CKD and the underlying mechanisms by which Mg may protect against vascular calcification. Lastly, we evaluate the strength of evidence from clinical studies on the efficacy of Mg supplementation and discuss future research directions.

Comparative Efficacy and Acceptability of 12 Phosphorus-Lowering Drugs in Adults with Hyperphosphatemia and Chronic Kidney Disease: A Systematic Review and Network Meta-Analysis

BACKGROUND

Hyperphosphatemia is associated with cardiovascular morbidity and mortality in adults with chronic kidney disease (CKD). Drug therapy has an irreplaceable role in the management of hyperphosphatemia.

OBJECTIVES

We aimed to compare and rank phosphorus-lowering drugs, including phosphate binder and nonphosphate binder, in hyperphosphatemia adults with CKD.

METHODS

We did a systematic review and frequentist random-effect network meta-analysis. We searched in PubMed, Cochrane Library, Web of Science, and Embase from inception to February 1, 2023, for randomized controlled trials of 12 phosphorus-lowering drugs in adults with hyperphosphatemia and CKD. Primary outcomes were efficacy (changes in serum phosphorus) and acceptability (treatment withdrawals due to any cause). We ranked each drug according to the value of surface under the cumulative ranking curve. We applied the Confidence in Network Meta-Analysis frameworks to rate the certainty of evidence. This study was registered with PROSPERO, number CRD42022322270.

RESULTS

We identified 2,174 citations, and of these, we included 94 trials comprising 14,459 participants and comparing 13 drugs or placebo. In terms of efficacy, except for niacinamide, all drugs lowered the level of serum phosphorus compared with placebo, with mean difference ranging between -1.61 (95% credible interval [CrI], -2.60 to -0.62) mg/dL for magnesium carbonate and -0.85 (-1.66 to -0.05) mg/dL for bixalomer. Only ferric citrate with odds ratios 0.56 (95% CrI: 0.36-0.89) was significantly associated with fewer dropouts for acceptability. Of the 94 trials, 43 (46%), 7 (7%), and 44 (47%) trials were rated as high, moderate, and low risk of bias, respectively, the certainty of the evidence was moderate to very low.

CONCLUSIONS

Magnesium carbonate has the best phosphorus-lowering effect in hyperphosphatemia adults with CKD; considering efficacy and acceptability, ferric citrate shows evidence to be the most appropriate drug with or without dialysis.

Lower serum magnesium is a predictor of left ventricular hypertrophy in patients on dialysis

PURPOSE

Left ventricular hypertrophy (LVH) represents one of the main risk factors for cardiovascular mortality in dialysis patients. Low serum magnesium Mg is related with increased mortality in general and dialysis population. Aim of our study was to evaluate the association of Mg with LVH and cardiac geometry in dialysis patients.

METHODS

Hemodialysis (HD) and peritoneal dialysis (PD) patients from nine nephrology departments were included. Echocardiographic LVH was defined by LV mass index > 95 g/m² in women and > 115 g/m² in men. Four LV geometric patterns were defined: normal, concentric remodeling, eccentric LVH and concentric LVH. Demographic and laboratory data were collected.

RESULTS

133 patients (68 HD, 65 PD) with a median age of 63 years (IQR 52-74) were studied. Mg correlated positively with creatinine, HDL and negatively with CRP levels and BMI. There were no significant differences in Mg between the modality groups. 80 patients presented LVH (43 HD and 37 PD patients). Patients with LVH were older (median age 68 vs 55 years, p < 0.001), with higher BMI (median 26.9 vs 24.7 kg/m², p = 0.009), had a history of PVD or CAD (55% vs 30.2%, p = 0.003), had higher pulse pressure (median 60 vs 50, p = 0.017), MIS score (median 5 vs 4, p = 0.011), lower albumin (median 3.5 vs 3.8 g/dl, p = 0.011) and Mg levels (median 2.1 vs 2.4 mg/dl, p < 0.001). In univariate analysis age, CVD comorbidities, pulse pressure, CRP, BMI, albumin, Mg, MIS and use of b-blockers or calcium blockers were LVH predictors. In multivariate analysis, Mg was an independent predictor of LVH, adjusted for age, MIS and b-blockers. Considering LV geometry, lower Mg levels were mainly correlated with concentric LVH.

CONCLUSION

Low serum magnesium levels seem to be an independent factor for LVH in hemodialysis and peritoneal dialysis patients.

Magnesium in Kidney Function and Disease-Implications for Aging and Sex-A Narrative Review

Magnesium (Mg) has a vital role in the human body, and the kidney is a key organ in the metabolism and excretion of this cation. The objective of this work is to compile the available evidence regarding the role that Mg plays in health and disease, with a special focus on the elderly population with chronic kidney disease (CKD) and the eventual sex differences. A narrative review was carried out by executing an exhaustive search in the PubMed, Scopus, and Cochrane databases. Ten studies were found in which the role of Mg and sex was evaluated in elderly patients with CKD in the last 10 years (2012-2022). The progression of CKD leads to alterations in mineral metabolism, which worsen as the disease progresses. Mg can be used as a coadjuvant in the treatment of CKD patients to improve glomerular filtration, but its use in clinical applications needs to be further characterized. In conclusion, there's a need for well-designed prospective clinical trials to advise and standardize Mg supplementation in daily clinical practice, taking age and sex into consideration.

Redefying the therapeutic strategies against cardiorenal morbidity and mortality: Patient phenotypes

Chronic kidney disease (CKD) patients face an unacceptably high morbidity and mortality, mainly from cardiovascular diseases. Diabetes mellitus, arterial hypertension and dyslipidemia are highly prevalent in CKD patients. Established therapeutic protocols for the treatment of diabetes mellitus, arterial hypertension, and dyslipidemia are not as effective in CKD patients as in the general population. The role of non-traditional risk factors (RF) has gained interest in the last decades. These entail the deranged clinical spectrum of secondary hyperparathyroidism involving vascular and valvular calcification, under the term “CKD-mineral and bone disorder” (CKD-MBD), uremia per se, inflammation and oxidative stress. Each one of these non-traditional RF have been addressed in various study designs, but the results do not exhibit any applied clinical benefit for CKD-patients. The “crusade” against cardiorenal morbidity and mortality in CKD-patients is in some instances, derailed. We propose a therapeutic paradigm advancing from isolated treatment targets, as practiced today, to precision medicine involving patient phenotypes with distinct underlying pathophysiology. In this regard we propose two steps, based on current stratification management of corona virus disease-19 and sepsis. First, select patients who are expected to have a high mortality, i.e., a prognostic enrichment. Second, select patients who are likely to respond to a specific therapy, i.e., a predictive enrichment.

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

Purpose of Review

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

Sources of Information

Peer-reviewed clinical trials and observational studies.

Methods

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

Key Findings

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

Limitations

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

Understanding the mechanistic roles of environmental heavy metal stressors in regulating ferroptosis: adding new paradigms to the links with diseases

Ferroptosis is a new type of iron-dependent cell death induced by a failure of the lipid repair protein GPX4 or the Xc- antiporter, which is essential for glutathione production. Some heavy metals such as arsenic (As), cobalt (Co), cadmium (Cd), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), mercury (Hg) as well as zinc (Zn) are shown to induce ferroptotic cell death involving the generation of oxidative stress, mitochondrial dysfunctioning, lipid peroxidation, and several other cellular etiologies. However, selenium (Se) treatment has been shown to enhance adaptive transcription responses to protect cells from ferroptosis. Heavy metals like Cadmium exposure activated ALK4/5 signaling via Smad3 and Akt signaling which leads to cell death mechanism. Continuous exposure to a small dose of mercury can damage tissues, and methylmercury bind to sulfhydryl proteins and GSH, this elevates oxidative stress, free radical accumulation, glutathione depletion, mitochondrial damage, and inhibited the nuclear factor-κB pathway which leads to ferroptotic cell death. Animals exposed to nickel and cobalt may have increased lipid peroxidation which can induce ferroptosis. Glutathione depletion is caused by Zn intoxication and exposure to manganese. These metals are systemic toxins that have been shown adverse effects on humans. Ferroptosis has recently been related to several pathological disorders, including, Alzheimer's disease, Parkinson's disease, Huntington's disease, as well as cardiovascular disease, and any type of cancer. For these disorders and some heavy metal toxicity, ferroptosis suppression needs to be looked upon as a promising therapeutic choice.

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 between hypomagnesemia and mortality among dialysis patients: a systematic review and meta-analysis

Background

Malnutrition-inflammation-atherosclerosis (MIA) syndrome is caused by the inflammatory cytokines in end stage renal disease (ESRD) patients, and MIA complex-related factors may be associated with hypomagnesemia and mortality. However, the association between serum magnesium level and mortality for dialysis patients is still not clear. Additionally, no meta-analysis has investigated the impact of serum magnesium on peritoneal dialysis and hemodialysis, separately.

Methods

We searched published studies in PubMed, Embase, Cochrane, Collaboration Central Register of Controlled Clinical Trials, and Cochrane Systematic Reviews through April 2022. Studies associated with serum magnesium and all-cause mortality or cardiovascular (CV) mortality in ESRD on kidney replacement therapy (KRT) patients were included. A hazard ratio (HR) with 95% confidence intervals (CI) was used to report the outcomes.

Results

Twenty-one studies involving 55,232 patients were included. Overall, there was a significant association between hypomagnesemia and all-cause mortality for dialysis patients (HR: 1.67, 95% CI [1.412-2.00], p < 0.001; certainty of evidence: moderate) using a mixed unadjusted and adjusted HR for analysis. There was also a significantly increased risk of CV mortality for individuals with hypomagnesemia compared with the non-hypomagnesemia group (HR 1.56, 95% CI [1.08-2.25], p < 0.001; certainty of evidence: moderate). In addition, a subgroup analysis demonstrated that hypomagnesemia was associated with a high risk of both all-cause mortality and CV mortality (all-cause mortality, HR:1.80, 95% CI [1.48-2.19]; CV mortality, HR:1.84, 95% CI [1.10-3.07]) in hemodialysis (HD) patients, but not in participants receiving peritoneal dialysis (PD; all-cause mortality, HR:1.26, 95% CI [0.84-1.91]; CV mortality, HR:0.66, 95% CI [0.22-2.00]). The systematic review protocol was prespecified and registered in PROSPERO [CRD42021256187].

Conclusions

Hypomagnesemia may be a significant risk factor for all-cause mortality and CV mortality in KRT patients, especially in those receiving hemodialysis. However, because of the limited certainty of evidence, more studies are required to investigate this association.

Dietary magnesium and risk of cardiovascular and all-cause mortality after myocardial infarction: A prospective analysis in the Alpha Omega Cohort

Background

An adequate intake of magnesium has been associated with lower risks of cardiovascular disease (CVD) and all-cause mortality in population-based studies. Whether an adequate magnesium intake is important for reducing long-term mortality risk after myocardial infarction (MI) is not yet clear.

Objective

We examined magnesium intake in relation to CVD, all-cause and coronary heart disease (CHD) mortality, on top of drug treatment, in patients who had experienced an MI.

Methods

We included 4,365 Dutch patients aged 60–80 y from the Alpha Omega Cohort with a history of MI &lt;10 y before study enrollment. Dietary data over the past month were collected at baseline using a 203-item validated food frequency questionnaire from which magnesium intake was calculated. Patients were followed for cause-specific mortality through December 2018. HRs for mortality in tertiles of energy adjusted magnesium intake were obtained from multivariable Cox proportional hazard models, adjusting for age, sex, education, obesity and other lifestyle and dietary factors. Associations were also studied in relevant subgroups, including patients with diabetes and diuretics users. Restricted cubic splines were used for studying the continuous association of magnesium intake with CVD mortality.

Results

The average magnesium intake was 302 ± 78 mg/day and 28% of male and 33% of female patients had adequate intakes. Magnesium containing supplements were used by 5.4% of the cohort. During a median follow-up of 12.4 years (48,473 person-years), 2,035 patients died, of which 903 from CVD and 558 from CHD. Higher magnesium intakes (&gt;320 g/d), compared to the reference group (&lt;283 mg/d), were associated with a lower risk of CVD mortality (HR: 0.72; 95% CI: 0.54–0.98) and all-cause mortality (HR: 0.78; 95% CI: 0.64–0.95) in the fully adjusted model. A non-significant inverse association was found for CHD mortality. Associations for CVD mortality were slightly stronger in diuretic users (HR: 0.55; 95% CI: 0.34–0.89). Results were similar after excluding magnesium supplement users.

Conclusion

An adequate intake of magnesium may be important for lowering long-term mortality risk after MI, especially in patients treated with diuretics. The Alpha Omega Trial was registered at clinicaltrials.gov as NCT03192410.

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

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

Tissue chaperoning—the expanded functions of fetuin-A beyond inhibition of systemic calcification

Traditionally, fetuin-A embodies the prototype anti-calcification protein in the blood, preventing cardiovascular calcification. Low serum fetuin-A is generally associated with mineralization dysbalance and enhanced mortality in end stage renal disease. Recent evidence indicates that fetuin-A is a crucial factor moderating tissue inflammation and fibrosis, as well as a systemic indicator of acute inflammatory disease. Here, the expanded function of fetuin-A is discussed in the context of mineralization and inflammation biology. Unbalanced depletion of fetuin-A in this context may be the critical event, triggering a vicious cycle of progressive calcification, inflammation, and tissue injury. Hence, we designate fetuin-A as tissue chaperone and propose the potential use of exogenous fetuin-A as prophylactic agent or emergency treatment in conditions that are associated with acute depletion of endogenous protein.

Magnesium—A More Important Role in CKD–MBD than We Thought

Chronic kidney disease (CKD) is associated with different complications, including chronic kidney disease–mineral and bone disorder (CKD–MBD), which represents a systemic disorder that involves the presence of different mineral or bone structure abnormalities (i.e., modification of bone turnover, strength, volume, etc.), including even vascular calcification development. Even if, over the years, different pathophysiological theories have been developed to explain the onset and progression of CKD–MBD, the influence and importance of serum magnesium level on the evolution of CKD have only recently been highlighted. So far, data are inconclusive and conflicting; therefore, further studies are necessary to validate these findings, which could be useful in developing a better, more adequate, and personalized management of CKD patients.

The association of serum magnesium and chronic kidney disease: a two-sample mendelian randomization study of European descent

BACKGROUND

Previous observational studies focused on the association of serum magnesium (SMg) and chronic kidney disease (CKD), but the conclusion was inconsistent. To investigate the causal relationship of SMg and CKD, we performed a two-sample mendelian randomization (TSMR) analysis using publicly datasets.

METHOD

In mendelian randomization (MR) analysis, we used single nucleotide polymorphisms (SNPs) which had genetic statistical significance with SMg but not associated with kidney function and confounding factors as instrumental variable (IV). To select SNPs, we used publicly database of Genome Wide Association Study (GWAS) and Chronic Kidney Disease Genetics (CKDGen) Confirms. We used inverse-variance weighted (IVW), weighted median, MR-Egger regression, weighted mode, and simple mode approaches in TSMR analysis.

RESULTS

We selected 4 SNPs (rs4072037, rs7965584, rs11144134 and rs448378) as IV. In IVW approach, the result of MR analysis for CKD was OR = 0.55, 95% CI: 0.06, 4.75, P = 0.58; for estimated glomerular filtration rate from creatinine (eGFR)crea was β = -0.06, 95% CI: -1.08, 0.07, P = 0.39; for estimated glomerular filtration rate from cystatin C (eGFR)cys was β = -0.03, 95% CI: -0.43, 0.36, P = 0.86, respectively per SD increase in SMg. When subgroup by diabetes mellitus (DM), the results for DM-eGFRcrea was β = -0.33, 95% CI: -0.85, 0.19, P = 0.21; and for non-DM-eGFRcrea was β = -0.03, 95% CI: -0.16, 0.11, P = 0.71. The results of other four MR approaches were consistent with IVW approach (all P > 0.05).

CONCLUSION

Our TSMR analysis showed that SMg had no causal effect on kidney function and progress CKD in European descent. As for the results about overall population, the verified study is needed in future study.

Magnesium intake by enteral formulation affects serum magnesium concentration in patients undergoing hemodialysis

Decreased serum magnesium levels are associated with mortality and fractures in patients with chronic kidney disease; however, there is no recommendation for Mg intake in these populations. This study used cross-sectional analysis to examine the association between Mg intake and serum Mg levels in patients undergoing hemodialysis. Sixty-one patients were included. The daily Mg intake was 185 mg (IQR: 151-203 mg), and serum Mg level was 2.4 mg/dL (IQR: 2.2-2.7 mg/dL). Multiple regression analysis showed that intake of enteral formulation by tube feeding was an independent factor associated with serum Mg level (B = 0.90 [95% confidence interval: 0.61-1.20], p < 0.01). These findings may aid in serum Mg level management through diet and enteral formulation in patients undergoing hemodialysis.

Effect of Magnesium Supplementation on Chronic Kidney Disease-Mineral and Bone Disorder in Hemodialysis Patients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Research about the effects of magnesium (Mg) supplementation on chronic kidney disease-mineral bone disorder (CKD-MBD) among hemodialysis (HD) patients is controversial. Thus, we conducted a meta-analysis to examine Mg supplementation's effects on CKD-MBD in patients requiring dialysis.

METHODS

The PubMed and EMBASE databases were searched for English language studies up to September 2020. The main indicators of our study were changes in serum Mg, calcium (Ca), phosphate, parathyroid hormone (PTH), and C-reactive protein levels, and carotid intima-media thickness (CIMT) after Mg supplementation. Mg efficacy was evaluated by weighted mean difference (WMD) and confidence intervals (CIs), and subgroup analyses of intervention type and intervention duration were also performed.

RESULTS

Eight eligible studies comprising 309 HD patients were included in our meta-analysis. Mg supplementation alone produced a negative effect on serum PTH levels (WMD = -236.56; 95% CI -349.71 to -123.41) and CIMT (WMD = -0.18; 95% CI -0.34 to -0.01). A subgroup analysis based on intervention type showed a significant improvement in serum Mg (WMD = 1.08; 95% CI 0.51-1.64) and Ca (WMD = -0.50; 95% CI -0.77 to -0.23) levels when Mg was administered via dialysate and oral medication, respectively. Different intervention durations had no effect on serum Mg levels. Mg supplementation had no significant effect on serum phosphate (WMD = -0.25; 95% CI -0.64 to 0.14) and C-reactive protein levels (WMD = -0.02; 95% CI -2.80 to 2,76).

CONCLUSIONS

Our results showed that Mg supplementation alone could improve CKD-MBD by regulating serum Ca and PTH metabolism and decreasing CIMT among HD patients.

Comparison of Sevelamer and Calcium Carbonate in Prevention of Hypomagnesemia in Hemodialysis Patients

BACKGROUND

Chronic kidney disease (CKD) is a life-threatening disease with numerous complications. Hemodialysis (HD) patients are prone to magnesium deficiency due to malnutrition, which can cause cardiovascular complications and increase mortality. The present study aimed to investigate the effects of sevelamer and calcium carbonate, as phosphate binders, on serum levels of magnesium, calcium, and phosphorus in HD patients.

METHODS

A parallel clinical trial was conducted on 54 patients undergoing HD at Kosar Hospital of Semnan. The inclusion criteria were end-stage renal disease (ESRD), alternative HD treatment for at least 3 months 3 times a week, and serum phosphate levels greater than 4.5 mg/dL. The participants were randomly assigned to two groups of sevelamer (n = 27) and calcium carbonate (n = 27). If the participants were taking a phosphate binder, they were asked to stop it for 3 weeks. Participants in the sevelamer group received 800 mg of sevelamer at most three times a day and those in the calcium carbonate group were treated with 500 mg of calcium carbonate at most 3 times a day. Before and 3 months after the intervention, the serum levels of calcium, magnesium, and phosphorus were measured through the Arsenazo method using the Pars Azmun kit in the Selectra auto-analyzer. Twenty-one patients in the sevelamer group and 22 patients in the calcium carbonate group finished the study.

RESULTS

The results showed that calcium carbonate and sevelamer increased serum magnesium level by 0.20 (P = 0.028) and 0.26 (P = 0.002), on average, which were statistically significant. The administration of calcium carbonate did not significantly change serum calcium levels (P = 0.53), whereas sevelamer reduced serum calcium levels by 0.23 (P = 0.017), on average. This reduction was statistically significant. The results also indicated that none of the calcium carbonate (P = 0.099) and sevelamer (P = 0.543) caused significant changes in serum phosphorus levels. The study findings showed no significant difference between the two groups in terms of changes in the serum levels of magnesium (0.590), calcium (0.116), and phosphorus (0.113).

CONCLUSIONS

Both drugs (Sevelamer and calcium carbonate) prevented hypomagnesemia and increased serum magnesium levels, but no significant differences were found in blood levels of calcium, phosphorus, and magnesium compared to the two drugs. Considering the effect of magnesium on cardiovascular diseases, increasing the serum magnesium levels through the administration of calcium carbonate and sevelamer can prevent the likelihood of cardiovascular diseases. However, none of the studied drugs was superior to the other in this regard.

A Role for SGLT-2 Inhibitors in Treating Non-diabetic Chronic Kidney Disease

In recent years, inhibitors of the sodium-glucose co-transporter 2 (SGLT2 inhibitors) have been shown to have significant protective effects on the kidney and the cardiovascular system in patients with diabetes. This effect is also manifested in chronic kidney disease (CKD) patients and is minimally due to improved glycaemic control. Starting from these positive findings, SGLT2 inhibitors have also been tested in patients with non-diabetic CKD or heart failure with reduced ejection fraction. Recently, the DAPA-CKD trial showed a significantly lower risk of CKD progression or death from renal or cardiovascular causes in a mixed population of patients with diabetic and non-diabetic CKD receiving dapagliflozin in comparison with placebo. In patients with heart failure and reduced ejection fraction, two trials (EMPEROR-Reduced and DAPA-HF) also found a significantly lower risk of reaching the secondary renal endpoint in those treated with an SGLT2 inhibitor in comparison with placebo. This also applied to patients with CKD. Apart from their direct mechanism of action, SGLT2 inhibitors have additional effects that could be of particular interest for patients with non-diabetic CKD. Among these, SGLT2 inhibitors reduce blood pressure and serum acid uric levels and can increase hemoglobin levels. Some safety issues should be further explored in the CKD population. SGLT2 inhibitors can minimally increase potassium levels, but this has not been shown by the CREDENCE trial. They also increase magnesium and phosphate reabsorption. These effects could become more significant in patients with advanced CKD and will need monitoring when these agents are used more extensively in the CKD population. Conversely, they do not seem to increase the risk of acute kidney injury.

The Emerging Role of Nutraceuticals in Cardiovascular Calcification: Evidence from Preclinical and Clinical Studies

Cardiovascular calcification is the ectopic deposition of calcium-phosphate crystals within the arterial wall and the aortic valve leaflets. This pathological process leads to increased vascular stiffness, reduced arterial elasticity, and aortic valve stenosis, increasing the risk of cardiovascular diseases. Although cardiovascular calcification is an increasing health care burden, to date no medical therapies have been approved for treating or preventing it. Considering the current lack of therapeutic strategies and the increasing prevalence of cardiovascular calcification, the investigation of some nutraceuticals to prevent this pathological condition has become prevalent in recent years. Recent preclinical and clinical studies evaluated the potential anti-calcific role of nutraceuticals (including magnesium, zinc, iron, vitamin K, and phytate) in the progression of vascular calcification, providing evidence for their dietary supplementation, especially in high-risk populations. The present review summarizes the current knowledge and latest advances for nutraceuticals with the most relevant preclinical and clinical data, including magnesium, zinc, iron, vitamin K, and phytate. Their supplementation might be recommended as a cost-effective strategy to avoid nutritional deficiency and to prevent or treat cardiovascular calcification. However, the optimal dose of nutraceuticals has not been identified and large interventional trials are warranted to support their protective effects on cardiovascular disease.

Impact of serum magnesium levels at hospital discharge and one-year mortality

Background: We aimed to determine the optimal range of discharge serum magnesium in hospitalized patients by evaluating one-year mortality risk according to discharge serum magnesium.Methods: This was a single-center cohort study of hospitalized adult patients who survived until hospital discharge. We classified discharge serum magnesium, defined as the last serum magnesium within 48 hours of hospital discharge, into ≤1.6, 1.7-1.8, 1.9-2.0, 2.1-2.2, and ≥2.3 mg/dL. We assessed one-year mortality risk after hospital discharge based on discharge serum magnesium, using discharge magnesium of 2.1-2.2 mg/dL as the reference group.Results: Of 39,193 eligible patients, 8%, 23%, 34%, 23%, and 12% had a serum magnesium of ≤1.6, 1.7-1.8, 1.9-2.0, 2.1-2.2, and ≥2.3 mg/dL, respectively, at hospital discharge. After the adjustment for several confounders, discharge serum magnesium of ≤1.6, 1.7-1.8, and ≥2.3 mg/dL were associated with higher one-year mortality with hazard ratio of 1.35 (95% CI 1.21-1.50), 1.14 (95% CI 1.06-1.24), and 1.17 (95% CI 1.07-1.28), respectively, compared to discharge serum magnesium of 2.1-2.2 mg/dL. There was no significant difference in one-year mortality between patients with discharge serum magnesium of 1.9-2.0 and 2.1-2.2 mg/dL.Conclusion: The optimal range of serum magnesium at discharge was 1.9-2.2 mg/dL. Both hypomagnesemia and hypermagnesemia at discharge were associated with higher one-year mortality.

Hypomagnesemia Is a Risk Factor for Cardiovascular Disease- and Noncardiovascular Disease-Related Mortality in Peritoneal Dialysis Patients

PURPOSE

Recent research has shown that hypomagnesemia is associated with increased all-cause mortality in hemodialysis patients. However, the relationship between the long-term prognosis of peritoneal dialysis (PD) and the study is not yet clear. This study will analyze the effects of hypomagnesemia on all-cause, cardiovascular diseases (CVD), and non-CVD mortality in PD patients.

METHOD

In a retrospective cohort study, 1,004 samples were selected from 7 PD centers in China. Based on the baseline blood magnesium level at the beginning of stable dialysis, all patients were classified into blood magnesium <0.7 mmol/L group, 0.7-1.2 mmol/L group, and >1.2 mmol/L group (the end event was death). The Kaplan-Meier method was used to calculate the difference in cumulative survival rate; the Cox proportional hazard model was used to analyze the risk factors of all-cause, CVD, and non-CVD death causes.

RESULTS

Cox multiple regression analysis results (reference comparison of 0.7-1.2 mmol/L group): patients with serum magnesium <0.7 mmol/L have a higher risk ratio of all-cause mortality (HR = 1.580, 95% CI: 1.222-2.042, p = 0.001), and it is also obvious after correction by multiple models (HR = 1.578, 95% CI: 1.196-2.083, p = 0.001). Subgroup analysis of the causes of death was as follows: CVD risk (HR = 1.628, 95% CI: 1.114-2.379, p = 0.012) and non-CVD risk (HR = 1.521, 95% CI: 1.011-2.288, p = 0.044). Further analysis of the causes of infection-related death in non-CVD is also significant (HR = 1.919, 95% CI: 1.131-3.1257, p = 0.016). On the other hand, the serum magnesium>1.2 mmol/L group had lower all-cause mortality after correction (HR = 0.687, 95% CI: 0.480-0.985, p = 0.041), and subgroup analysis of the cause of death had no statistical significance (p > 0.05).

CONCLUSIONS

Hypomagnesemia (serum magnesium <0.7 mmol/L) during stable dialysis in PD patients is a risk factor for CVD- and non-CVD-related mortality, especially infection-related death causes.

Serum Magnesium and Cardiovascular Outcomes and Mortality in CKD: The Chronic Renal Insufficiency Cohort (CRIC)

RATIONALE & OBJECTIVE

Low serum magnesium level has been shown to be associated with increased mortality, but its role as a predictor of cardiovascular disease is unclear. This study evaluates the association between serum magnesium level and cardiovascular events and all-cause mortality in a large cohort of individuals with chronic kidney disease (CKD).

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

3,867 participants with CKD, enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study.

EXPOSURES

Serum magnesium measured at study baseline.

OUTCOMES

Composite cardiovascular events (myocardial infarction, cerebrovascular accident, heart failure, and peripheral arterial disease) and all-cause mortality.

ANALYTICAL APPROACH

Cox proportional hazards models adjusted for demographic, clinical, and laboratory characteristics.

RESULTS

During the 14.6 (4.4) years (standard deviation) of follow-up, 1,384 participants died (36/1,000 person-years), and 1,227 (40/1,000 person-years) had a composite cardiovascular event. There was a nonlinear association between serum magnesium level and all-cause mortality. Low and high magnesium levels were associated with greater rates of all-cause mortality after adjusting for demographics, comorbid conditions, medications including diuretics, estimated glomerular filtration rate, and proteinuria (P < 0.001). No significant associations were observed between serum magnesium levels and the composite cardiovascular events. Low serum magnesium level was associated with incident atrial fibrillation (HR, 1.36; 95% CI, 1.01-1.82; P = 0.04).

LIMITATIONS

Single measurement of serum magnesium.

CONCLUSIONS

In this large CKD cohort, serum magnesium level < 1.9 mg/dL and >2.1 mg/dL was associated with increased risk for all-cause mortality. Low magnesium level was associated with incident atrial fibrillation but not with composite cardiovascular disease events. Further studies are needed to determine the optimal range of serum magnesium in CKD to prevent adverse clinical outcomes.

Calciprotein particles: mineral behaving badly?

PURPOSE OF REVIEW

Calciprotein particles (CPP) are formed in supersaturated solutions of calcium, phosphate and the mineral-binding protein fetuin-A. CPP have garnered considerable interest as potential mediators of mineral stress, but little consideration has been given to their origin, clearance and role in metabolism.

RECENT FINDINGS

CPP are made whilst buffering the mineral absorbed from the intestine after a meal or during remodelling of bone matrix. The postprandial rise in circulating CPP rise may be sensed by osteoblasts/osteocytes in bone, stimulating the secretion of the master phosphatonin fibroblast growth factor 23. Amorphous calcium phosphate-containing CPP are rapidly cleared by endothelial cells in the liver whereas crystalline apatite-containing CPP are filtered by phagocytic cells of the reticuloendothelial system. Impaired excretory function in kidney disease may lead to accumulation of CPP and its precursors with possible pathological sequalae. Inability to stabilize CPP in fetuin-A-deficiency states can result in intraluminal precipitation and inflammatory cascades if other mineralisation regulatory networks are compromised.

SUMMARY

CPP allow efficient transport and clearance of bulk calcium phosphate as colloids without risk of precipitation. As circulating factors, CPP may couple dietary mineral exposure with endocrine control of mineral metabolism in bone, signalling the need to dispose of excess phosphate from the body.

Emperor's syndrome in the COVID-19 era: Time for patient-centered nephrology?

The coronavirus disease-19 (COVID-19) pandemic has been a wake-up call in which has forced us to react worldwide. Health policies and practices have attracted particular attention in terms of human and financial cost. Before COVID-19, chronic kidney disease was already considered a risk multiplier in patients with diabetes and hypertension, the two now being the major risk factors for COVID-19 infection and adverse outcome. In contrast to the urgent need for action, the nephrology field is considered to be in a state of stagnation regarding the management of chronic kidney disease patients who still experience unacceptably high morbidity and mortality. Ironically and paradoxically in a field lacking robust clinical trials, clinical practice is driven by guidelines-based medicine on weak evidence. The Emperor's syndrome, referring to Hans Christian Andersen's fairy tale, has been described in medicine as voluntary blindness to an obvious truth, being a weak evidence-based therapeutic intervention or weak health care. A promising positive example of improving heart and kidney outcomes is the emerging treatment with sodium-glucose cotransporter 2 inhibitors. COVID-19 could boost actions for patient-centered care as a positive shift in nephrology care.

Magnesium: The recent research and developments

Magnesium is the fourth most abundant mineral in the human body, which facilitates more than 300 enzymatic reactions. Magnesium is essential for nucleic material and protein synthesis, neuromuscular conduction, cardiac contractility, energy metabolism, and immune system function. Gastrointestinal system and kidneys closely regulate magnesium absorption and elimination to maintain adequate storage of magnesium. Magnesium deficiency has been linked to many diseases and poor health outcomes. Magnesium has also been proven to be an effective therapeutic agent in many diseases, such as bronchial asthma, cardiac arrhythmia, and pre-eclampsia.

Association of serum magnesium level change with in-hospital mortality

The objective of this study was to assess the association of in-hospital mortality risk based on change in serum magnesium levels in hospitalised patients. All adult patients admitted to our hospital from years 2009 to 2013 with at least two serum magnesium measurements during hospitalisation were included. Serum magnesium change, defined as the absolute difference between the highest and lowest serum magnesium, was categorised into six groups: 0-0.2, 0.3-0.4, 0.5-0.6, 0.7-0.8, 0.9-1.0, ≥1.1 mg/dL. In-hospital mortality was the outcome of interest. Logistic regression was used to assess the association between serum magnesium change and in-hospital mortality, using serum magnesium change of 0.0-0.2 mg/dL as the reference group. A total of 42 141 patients, with the median serum magnesium change during hospital stay of 0.3 (IQR 0.2-0.6) mg/dL, were studied. In-hospital mortality based on serum magnesium change of 0-0.2, 0.3-0.4, 0.5-0.6, 0.7-0.8, 0.9-1.0, ≥1.1 mg/dL was 1.3%, 2.3%, 3.1%, 5.0%, 6.5%, and 8.8%, respectively (p<0.001). After adjustment for potential confounders, increased serum magnesium change was significantly associated with higher in-hospital mortality with adjusted OR of 1.39 (95% 1.14-1.69) in serum magnesium change of 0.3-0.4, 1.48 (95% CI 1.21 to 1.81) in 0.5-0.6, 1.89 (95% CI 1.53 to 2.34) in 0.7-0.8, 1.85 (95% CI 1.45 to 2.37) in 0.9-1.0 and 1.89 (95% CI 1.48 to 2.41) in ≥1.1 mg/dL when compared with serum magnesium change group of 0-0.2 mg/dL. Increased in-hospital mortality was associated with both downward and upward trends of serum magnesium change during hospitalisation. The greater extent of change in serum magnesium levels was progressively associated with increased in-hospital mortality.

The Role of Disturbed Mg Homeostasis in Chronic Kidney Disease Comorbidities

Some of the critical mechanisms that mediate chronic kidney disease (CKD) progression are associated with vascular calcifications, disbalance of mineral metabolism, increased oxidative and metabolic stress, inflammation, coagulation abnormalities, endothelial dysfunction, or accumulation of uremic toxins. Also, it is widely accepted that pathologies with a strong influence in CKD progression are diabetes, hypertension, and cardiovascular disease (CVD). A disbalance in magnesium (Mg) homeostasis, more specifically hypomagnesemia, is associated with the development and progression of the comorbidities mentioned above, and some mechanisms might explain why low serum Mg is associated with negative clinical outcomes such as major adverse cardiovascular and renal events. Furthermore, it is likely that hypomagnesemia causes the release of inflammatory cytokines and C-reactive protein and promotes insulin resistance. Animal models have shown that Mg supplementation reverses vascular calcifications; thus, clinicians have focused on the potential benefits that Mg supplementation may have in humans. Recent evidence suggests that Mg reduces coronary artery calcifications and facilitates peripheral vasodilation. Mg may reduce vascular calcification by direct inhibition of the Wnt/β-catenin signaling pathway. Furthermore, Mg deficiency worsens kidney injury induced by an increased tubular load of phosphate. One important consequence of excessive tubular load of phosphate is the reduction of renal tubule expression of α-Klotho in moderate CKD. Low Mg levels worsen the reduction of Klotho induced by the tubular load of phosphate. Evidence to support clinical translation is yet insufficient, and more clinical studies are required to claim enough evidence for decision-making in daily practice. Meanwhile, it seems reasonable to prevent and treat Mg deficiency. This review aims to summarize the current understanding of Mg homeostasis, the potential mechanisms that may mediate the effect of Mg deficiency on CKD progression, CVD, and mortality.

[Magnesium: Relevance for general practitioners - a position paper of the Society for Magnesium Research e. V.]

Magnesium deficiency is to be expected in the population and particularly among risk groups. Magnesium deficiency can cause numerous symptoms, is per se pathological and thus requires treatment. Diagnostics is based on clinical symptoms in conjunction with anamnestic criteria and laboratory parameters. Insufficient magnesium supply is associated with an increased risk for many diseases, e. g. metabolic syndrome, type 2 diabetes and cardiovascular diseases. Magnesium deficiency often appears as comorbidity and may exacerbate diseases. Physicians should pay more attention to magnesium in order to avoid deficits as a cause for multiple symptoms and risk factor for diseases. Optimisation of magnesium status may make an important contribution to the prevention of diseases. Oral magnesium therapy is safe and cost effective.

A Higher Concentration of Dialysate Magnesium to Reduce the Frequency of Muscle Cramps: A Narrative Review

Purpose of review:

Strategies to mitigate muscle cramps are a top research priority for patients receiving hemodialysis. As hypomagnesemia is a possible risk factor for cramping, we reviewed the literature to better understand the physiology of cramping as well as the epidemiology of hypomagnesemia and muscle cramps. We also sought to review the evidence from interventional studies on the effect of oral and dialysate magnesium-based therapies on muscle cramps.

Sources of information:

Peer-reviewed articles.

Methods:

We searched for relevant articles in major bibliographic databases including MEDLINE and EMBASE. The methodological quality of interventional studies was assessed using a modified version of the Downs and Blacks criteria checklist.

Key findings:

The etiology of muscle cramps in patients receiving hemodialysis is poorly understood and there are no clear evidence-based prevention or treatment strategies. Several factors may play a role including a low concentration of serum magnesium. The prevalence of hypomagnesemia (concentration of <0.7 mmol/L) in patients receiving hemodialysis ranges from 10% to 20%. Causes of hypomagnesemia include a low dietary intake of magnesium, use of medications that inhibit magnesium absorption (eg, proton pump inhibitors), increased magnesium excretion (eg, high-dose loop diuretics), and a low concentration of dialysate magnesium. Dialysate magnesium concentrations of ≤0.5 mmol/L may be associated with a decrease in serum magnesium concentration over time. Preliminary evidence from observational and interventional studies suggests a higher dialysate magnesium concentration will raise serum magnesium concentrations and may reduce the frequency and severity of muscle cramps. However, the quality of evidence supporting this benefit is limited, and larger, multicenter clinical trials are needed to further determine if magnesium-based therapy can reduce muscle cramps in patients receiving hemodialysis. In studies conducted to date, increasing the concentration of dialysate magnesium appears to be well-tolerated and is associated with a low risk of symptomatic hypermagnesemia.

Limitations:

Few interventional studies have examined the effect of magnesium-based therapy on muscle cramps in patients receiving hemodialysis and most were nonrandomized, pre-post study designs.

Use of proton pump inhibitors in dialysis patients: a double-edged sword?

Large cohort-based studies have shown that proton pump inhibitors (PPIs) are linked to rare but multiple and varied secondary events when used in the general population. Although clinicians accept the negative effects of PPIs on renal function, there is a lack of available data regarding the potential consequences of their use by dialysis patients in whom the risk of gastrointestinal bleeding is quite high. This review aims to highlight the risks and benefits of PPIs use in dialysis patients. To summarize, the benefit on the reduction of high digestive bleeding seems certain, but without any beneficial impact on overall survival. The impact on quality of life seems to be significant. The data on the occurrence of peritonitis during PPIs treatment are very contradictory. There is evidence regarding the occurrence of hypomagnesaemia in haemodialysis patients with PPIs; which may lead to increase bone fragility. New data show an increased cardiovascular risk and even a risk of death linked to the use of PPIs on dialysis. Several mechanisms of IPP toxicity are advanced to explain these findings.

Impact of admission serum magnesium levels on long-term mortality in hospitalized patients

BACKGROUND

The impact of admission serum magnesium on long-term mortality in hospitalized patients was unclear. This study aimed to assess the long-term mortality risk based on admission of serum magnesium in hospitalized patients.

METHODS

This was a retrospective cohort study conducted at a tertiary referral hospital. We included all adult patients admitted to Mayo Clinic Hospital, Minnesota, between 1 January 2009 and 31 December 2013, who had available admission serum magnesium. We categorized serum magnesium into ≤1.4, 1.5-1.6, 1.7-1.8, 1.9-2.0, 2.1-2.2, ≥2.3 mg/dL. We estimated the 1-year mortality risk based on various admission serum magnesium levels using Kaplan-Meier plot and assessed the association of admission serum magnesium with 1-year mortality using Cox proportional hazard analysis. We selected serum magnesium of 1.7-1.8 mg/dL as the reference group for mortality comparison.

RESULTS

We included a total of 65,974 patients, with a mean admission serum magnesium of 1.9 ± 0.3 mg/dL in this study. The 1-year mortality was 15.7%, 15.8%, 15.5%, 16.7%, 19.0%, and 25.6% in admission serum magnesium of ≤1.4, 1.5-1.6, 1.7-1.8, 1.9-2.0, 2.1-2.2, ≥2.3 mg/dL, respectively (p < 0.001). After adjustment for confounders, admission serum magnesium of 1.9-2.0, 2.1-2.2, and ≥2.3 mg/dL were significantly associated with increased 1-year mortality compared with magnesium of 1.7-1.8 mg/dL with adjusted HR of 1.09 (95% CI 1.02-1.15), 1.22 (95% CI 1.14-1.30), and 1.55 (95% CI 1.45-1.55), respectively. There was no significant difference in 1-year mortality risk between low serum magnesium ≤1.6 mg/dL and magnesium of 1.7-1.8 mg/dL.

CONCLUSION

Hypermagnesemia, but not hypomagnesemia, at the time of hospital admission was associated with increased 1-year mortality among hospitalized patients.

Serum magnesium, mortality and disease progression in chronic kidney disease

Introduction

Magnesium disorders are commonly encountered in chronic kidney disease (CKD) and are typically a consequence of decreased kidney function or frequently prescribed medications such as diuretics and proton pump inhibitors. While hypomagnesemia has been linked with increased mortality, the association between elevated magnesium levels and mortality is not clearly defined. Additionally, associations between magnesium disorders, type of death, and CKD progression have not been reported. Therefore, we studied the associations between magnesium levels, CKD progression, mortality, and cause specific deaths in patients with CKD.

Methods

Using the Cleveland Clinic CKD registry, we identified 10,568 patients with estimated Glomerular Filtration Rate (eGFR) between 15 and 59 ml/min/1.73 m² in this range for a minimum of 3 months with a measured magnesium level. We categorized subjects into 3 groups based on these magnesium levels (≤ 1.7, 1.7–2.6 and > 2.6 mg/dl) and applied cox regression modeling and competing risk models to identify associations with overall and cause-specific mortality. We also evaluated the association between magnesium level and slope of eGFR using mixed models.

Results

During a median follow-up of 3.7 years, 4656 (44%) patients died. After adjusting for relevant covariates, a magnesium level < 1.7 mg/dl (vs. 1.7–2.6 mg/dl) was associated with higher overall mortality (HR = 1.14, 95% CI: 1.04, 1.24), and with higher sub-distribution hazards for non-cardiovascular non-malignancy mortality (HR = 1.29, 95% CI: 1.12, 1.49). Magnesium levels > 2.6 mg/dl (vs. 1.7–2.6 mg/dl) was associated with a higher risk of all-cause death only (HR = 1.23, 95% CI: 1.03, 1.48). We found similar results when evaluating magnesium as a continuous measure. There were no significant differences in the slope of eGFR across all three magnesium groups (p = 0.10).

Conclusions

In patients with CKD stage 3 and 4, hypomagnesemia was associated with higher all-cause and non-cardiovascular non-malignancy mortality. Hypermagnesemia was associated with higher all-cause mortality. Neither hypo nor hypermagnesemia were associated with an increased risk of CKD progression.

Inflammation and Oxidative Stress in Chronic Kidney Disease-Potential Therapeutic Role of Minerals, Vitamins and Plant-Derived Metabolites

Chronic kidney disease (CKD) is a debilitating pathology with various causal factors, culminating in end stage renal disease (ESRD) requiring dialysis or kidney transplantation. The progression of CKD is closely associated with systemic inflammation and oxidative stress, which are responsible for the manifestation of numerous complications such as malnutrition, atherosclerosis, coronary artery calcification, heart failure, anemia and mineral and bone disorders, as well as enhanced cardiovascular mortality. In addition to conventional therapy with anti-inflammatory and antioxidative agents, growing evidence has indicated that certain minerals, vitamins and plant-derived metabolites exhibit beneficial effects in these disturbances. In the current work, we review the anti-inflammatory and antioxidant properties of various agents which could be of potential benefit in CKD/ESRD. However, the related studies were limited due to small sample sizes and short-term follow-up in many trials. Therefore, studies of several anti-inflammatory and antioxidant agents with long-term follow-ups are necessary.

Magnesium: An old player revisited in the context of CKD-MBD

Chronic kidney disease (CKD) is associated with a wide number of abnormalities in mineral metabolism. Often, these alterations are the leading players in the development of comorbidities associated with CKD, which are risk factors of mortality. In this context, mineral and bone disorder associated with CKD (CKD-MBD) are highlighted, connecting bone, renal, and cardiovascular disorders. Many studies have been led to propose strategies to avoid, reduce, or slow down CKD-MBD progression using different compositions of metallic elements-based P binders such as aluminum, magnesium, or calcium. Magnesium, the aim of this review, has been used by nephrologists to treat CKD-MBD with a variable acceptation due mainly to different results on bone homeostasis. Nowadays, we have new evidence about the efficacy of magnesium supplementation on vascular calcification, renal function, and bone disorders, suggesting potential beneficial effects of Magnesium in the management of CKD-MBD.

Proton pump inhibitor use and progression to major adverse renal events: a competing risk analysis

BACKGROUND

Proton pump inhibitors (PPIs) are associated with acute tubulointerstitial nephritis and there are reports associating their use with the development of chronic kidney disease (CKD).

AIM

To determine if PPI use is associated with major adverse renal events (MARE) in patients with CKD.

DESIGN

Observational cohort study comprising patients with CKD attending secondary care renal clinics from 1 January 2006 until 31 December 2016.

METHODS

We collated baseline clinical, socio-demographic and biochemical data at start of PPI (PPI group) or study inception (control group). MARE was considered a composite of doubling of creatinine or end-stage renal disease. Association between PPI exposure and progression to MARE was assessed by cause-specific hazards competing risk survival analysis.

RESULTS

There were 3824 patients with CKD included in the analyses of whom 1195 were prescribed a PPI. The PPI group was younger (64.8 vs. 67.0 years, P < 0.001), with lower estimated glomerular filtration rate (eGFR) (30 vs. 35 ml/min, P < 0.001) and more proteinuria (64 vs. 48 mg/mmol, P < 0.001). PPI use was associated with progression to MARE on multivariable adjustment (hazard ratio 1.13 [95% confidence interval 1.02-1.25], P = 0.021). Other factors significantly associated with progression to MARE were higher systolic blood pressure, lower eGFR, greater proteinuria, congestive cardiac failure and diabetes. Hypomagnesaemia was more common in the PPI group (39.5 vs. 18.9%, P < 0.001).

CONCLUSION

PPI use was associated with progression to MARE, but not death in patients with CKD after adjusting for factors known to predict declining renal function, including lower eGFR, proteinuria and comorbidities. A prospective cohort study is required to validate these findings.

Vegetable-Based Diets for Chronic Kidney Disease? It Is Time to Reconsider

Traditional dietary recommendations to renal patients limited the intake of fruits and vegetables because of their high potassium content. However, this paradigm is rapidly changing due to the multiple benefits derived from a fundamentally vegetarian diet such as, improvement in gut dysbiosis, reducing the number of pathobionts and protein-fermenting species leading to a decreased production of the most harmful uremic toxins, while the high fiber content of these diets enhances intestinal motility and short-chain fatty acid production. Metabolic acidosis in chronic kidney disease (CKD) is aggravated by the high consumption of meat and refined cereals, increasing the dietary acid load, while the intake of fruit and vegetables is able to neutralize the acidosis and its deleterious consequences. Phosphorus absorption and bioavailability is also lower in a vegetarian diet, reducing hyperphosphatemia, a known cause of cardiovascular mortality in CKD. The richness of multiple plants in magnesium and vitamin K avoids their deficiency, which is common in these patients. These beneficial effects, together with the reduction of inflammation and oxidative stress observed with these diets, may explain the reduction in renal patients' complications and mortality, and may slow CKD progression. Finally, although hyperkalemia is the main concern of these diets, the use of adequate cooking techniques can minimize the amount absorbed.