A Randomized Trial of Magnesium Oxide and Oral Carbon Adsorbent for Coronary Artery Calcification in Predialysis CKD

Assessment and management of magnesium and trace element status in children with CKD stages 2-5, on dialysis and post-transplantation: Clinical practice points from the Pediatric Renal Nutrition Taskforce

Children and young people with chronic kidney disease (CKD) are at risk for deficiency or excess of magnesium and trace elements. Kidney function, dialysis, medication, and dietary and supplemental intake can affect their biochemical status. There is much uncertainty about the requirements of magnesium and trace elements in CKD, which leads to variation in practice. The Pediatric Renal Nutrition Taskforce is an international team of pediatric kidney dietitians and pediatric nephrologists, formed to develop evidence-based clinical practice points to improve the nutritional care of children with CKD. PICO (patient, intervention, comparator, and outcomes) questions led the literature searches, which were conducted to ascertain current biochemical status, dietary intake, and factors leading to requirements differing from healthy peers, and to guide nutritional care of children with CKD stages 2-5, on dialysis, and post-transplantation. We address the assessment and intervention of magnesium and the trace elements chromium, copper, fluoride, iodine, manganese, selenium, and zinc. We suggest routine biochemical assessment of magnesium. Trace element assessment is based on clinical suspicion of deficiency or excess and their risk factors, including accumulation, losses, medications, nutrient interactions, and comorbidities. In particular, we suggest assessing magnesium, copper, iodine, and zinc when growth is poor, and evaluating magnesium, copper, selenium, and zinc in the presence of proteinuria. A structured approach to magnesium and trace element management, including biochemical, physical, and dietary assessment, is beneficial in the paucity of evidence. Research recommendations are suggested.

Chronic kidney disease-mineral and bone disorder: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

In 2017, Kidney Disease: Improving Global Outcomes (KDIGO) published a Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Since then, new lines of evidence have been published related to evaluating disordered mineral metabolism and bone quality and turnover, identifying and inhibiting vascular calcification, targeting vitamin D levels, and regulating parathyroid hormone. For an in-depth consideration of the new insights, in October 2023, KDIGO held a Controversies Conference on CKD-MBD: Progress and Knowledge Gaps Toward Personalizing Care. Participants concluded that the recommendations in the 2017 CKD-MBD guideline remained largely consistent with the available evidence. However, the framework of the 2017 Guideline, with 3 major sections-biochemical abnormalities in mineral metabolism; bone disease; and vascular calcification-may no longer best reflect currently available evidence related to diagnosis and treatment. Instead, future guideline efforts could consider mineral homeostasis and deranged endocrine systems in adults within a context of 2 clinical syndromes: CKD-associated osteoporosis, encompassing increased fracture risk in patients with CKD; and CKD-associated cardiovascular disease, including vascular calcification and structural abnormalities, such as valvular calcification and left ventricular hypertrophy. Participants emphasized that the complexity of bone and cardiovascular manifestations of CKD-MBD necessitates personalized approaches to management.

Upper normal serum magnesium is associated with a reduction in incident death from fatal heart failure, coronary heart disease and stroke in non-dialysis patients with CKD stages 4 and 5

Background

Serum magnesium disturbances are common in patients with cardiovascular disease (CVD). However, the well-established link between low serum magnesium and nutritional or inflammatory disorders has limited its consideration as a non-traditional risk factor for mortality. This study aims to elucidate the relationship between serum magnesium concentrations and mortality due to fatal heart failure (HF), coronary heart disease (CHD) and stroke in non-dialysis patients with chronic kidney disease (CKD) stages 4 and 5.

Methods

A cohort of 1271 non-dialysis patients with CKD stages 4 and 5 was followed from 2008 to 2018. Patients with prior major adverse cardiovascular events (MACE) were excluded. Serum magnesium levels were stratified into tertiles and the primary outcomes were incidence rates of fatal HF, CHD and stroke. Secondary outcomes included composite MACE and all-cause mortality. Hazard ratios (HRs) were calculated using multivariate Cox regression, adjusting for demographics, comorbidities and biochemical parameters. E-values were used to assess the robustness of the results.

Results

Over the 10-year follow-up, 186 patients died. Higher serum magnesium levels were significantly associated with reduced mortality risk from HF [HR 0.49 (95% CI 0.27-0.89) for T2; HR 0.31 (95% CI 0.16-0.60) for T3] compared with the lowest tertile. Similar trends were observed for CHD and stroke mortality. The incidence rate of MACE per 1000 person-years was reduced from 68.2 in tertile 1 to 26.2 in tertile 2 and 16.8 in tertile 3. Secondary endpoints, including all-cause mortality and composite MACE, followed trends similar to the primary outcomes.

Conclusions

Higher serum magnesium concentrations were associated with lower risks of death from fatal HF, CHD and stroke in non-dialysis patients with CKD stages 4 and 5.

Lower serum magnesium levels are associated with a higher risk of fractures and vascular calcifications in hemodialysis patients

Background

Magnesium (Mg) deficiency seems to be associated with altered bone metabolism and vascular calcifications (VC). This study aimed to evaluate the association between serum Mg levels and incident bone fragility fractures and VC in a cohort of prevalent hemodialysis (HD) patients.

Methods

We performed a retrospective study of 206 patients, with a mean age of 68.3 ± 13.1 years; 121 (59%) were male, and the median follow-up time was 58 months.

Results

Thirty-seven episodes of fragility fractures were identified with a median HD vintage of 42 months-an incidence rate of 29 per 1000 person-years. Patients with fractures showed lower Mg levels compared with those without fractures (P < .001) and more VC (P = .01). In a Cox regression analysis, time to fragility fracture was independently associated with serum Mg <2.2 mg/dL (P < .001), in a model adjusted to age, female gender, HD vintage, diabetes mellitus, body mass index, albumin, parathyroid hormone, active vitamin D therapy and the presence of VC. Patients with Mg serum levels <2.2 mg/dL had a 1.32-fold higher risk of fragility fractures (P < .001).

Conclusions

This study showed that the incidence of bone fragility fractures in HD patients is high and is significantly associated with lower Mg levels and with the presence of more VC.

The effect of sevelamer on serum calcification propensity in patients with chronic kidney disease: the results of a multicentre, double-blind, placebo-controlled, randomized clinical trial

Background

The serum calcification propensity test (or T50 test) might become a standard tool for the assessment of vascular calcification risk and T50 might be a valuable biomarker in clinical trials of treatments intended to slow the progression of vascular calcification. Literature data suggest that non-calcium-containing phosphate binders can influence T50 in chronic dialysed patients. However, it is not clear whether similar interventions are effective in patients at earlier stages of chronic kidney disease (CKD).

Methods

The FGF23 Reduction: Efficacy of a New phosphate binder in CHronic kidney disease (FRENCH) trial was a multicentre, double-blind, placebo-controlled, randomized trial of sevelamer carbonate in participants with stage 3b/4 CKD. In this subanalysis of the FRENCH data, T50 and other laboratory variables (including fetuin-A and ionized and total magnesium) were measured centrally at baseline and after 12 weeks of treatment.

Results

A total of 96 patients were screened and 78 (55 men and 23 women) met the inclusion criteria and were randomized to receive placebo (n = 39) or sevelamer carbonate (n = 39). The median patient age was 66 years [interquartile range (IQR) 56-72], the median eGFR was 25 ml/min/1.73 m2 (IQR 21-30) and the mean T50 was 335 minutes (standard deviation 82). In a linear regression model, T50 was independently associated with serum ionized magnesium, fetuin-A and bicarbonate levels and inversely associated with phosphate concentration. The within-group changes in the mean T50 between week 0 and week 12 were not significant in the sevelamer group or the placebo group {4.6 minutes [95% confidence interval (CI) -13.6-22.8; P = .61] and 7.8 minutes [95% CI -16.4-32.1; P = .51], respectively}. Furthermore, we did not observe significant changes in fetuin-A and magnesium levels.

Conclusion

A 12-week course of the non-calcium-containing phosphate binder sevelamer carbonate was not associated with a significant change in T50 in patients with stage 3b/4 CKD. Phosphate binders might not be an effective strategy for modifying serum calcification propensity in non-dialysis-dependent patients with CKD.

Research progress on the association between TMAO and vascular calcification in patients with chronic kidney disease

Vascular calcification (VC) is a common complication in patients with chronic kidney disease (CKD) and a major risk factor for increased cardiovascular mortality in patients with CKD. Its pathology and pathogenesis are complex and have not been fully elucidated. Trimethylamine N-oxide (TMAO) is an enteric-borne uremic toxin that has been found to play a role in the progression of VC. This article mainly reviews the metabolism of TMAO, the relationship between TMAO and VC in CKD patients, and possible treatments for TMAO, aiming to further explore the mechanism of VC occurrence in CKD patients and provide potential diagnostic and treatment strategies.

Associations of Cognitive Function with Serum Magnesium and Phosphate in Hemodialysis Patients: A Cross-Sectional Analysis of the Osaka Dialysis Complication Study (ODCS)

Cognitive impairment and dementia are common in patients with chronic kidney disease, including those undergoing hemodialysis. Since magnesium and phosphate play important roles in brain function and aging, alterations in these and other factors related to bone mineral disorder (MBD) may contribute to low cognitive performance in patients on hemodialysis. This cross-sectional study examined the associations between cognitive function and MBD-related factors among 1207 patients on maintenance hemodialysis. Cognitive function was assessed by the Modified Mini-Mental State examination (3MS). The exposure variables of interest were serum magnesium, phosphate, calcium, calcium-phosphate product, intact parathyroid hormone, fetuin-A, T50 calciprotein crystallization test, use of phosphate binders, use of cinacalcet, and use of vitamin D receptor activators. Multivariable-adjusted linear regression models were used to examine the associations between 3MS and each of the exposure variables independent of 13 potential non-mineral confounders. We found that lower 3MS was associated with lower serum magnesium, lower phosphate, lower calcium-phosphate product, and nonuse of phosphate binders. These results suggest that magnesium and phosphate play potentially protective roles against cognitive impairment in this population.

Association between serum magnesium levels and cognitive function in patients undergoing hemodialysis

BACKGROUND

The relationship between chronic kidney disease-mineral and bone disorder (CKD-MBD) and cognitive function remains largely unknown. This cross-sectional study aimed to explore the association between CKD-MBD and cognitive function in patients on hemodialysis.

METHODS

Hemodialysis patients aged ≥ 65 years without diagnosed dementia were included. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE). CKD-MBD markers, serum magnesium, intact parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OHD), fibroblast growth factor (FGF)-23, and soluble α-klotho were measured.

RESULTS

Overall, 390 patients with a median age of 74 (interquartile range, 70-80) years, mean serum magnesium level of 2.4 ± 0.3 mg/dL, and median MoCA and MMSE scores of 25 (22-26) and 28 (26-29), respectively, were analyzed. MoCA and MMSE scores were significantly higher (preserved cognitive function) in the high-magnesium group than in the low-magnesium group according to the unadjusted linear regression analysis (β coefficient [95% confidence interval (CI)] 1.05 [0.19, 1.92], P = 0.017 for MoCA; 1.2 [0.46, 1.94], P = 0.002 for MMSE) and adjusted multivariate analysis with risk factors for dementia (β coefficient [95% CI] 1.12 [0.22, 2.02], P = 0.015 for MoCA; 0.92 [0.19, 1.65], P = 0.014 for MMSE).

CONCLUSIONS

Higher serum magnesium levels might be associated with preserved cognitive function in hemodialysis patients. Conversely, significant associations were not observed between cognitive function and intact PTH, 25-OHD, FGF-23, or soluble α-klotho levels.

The Dual Burden: Exploring Cardiovascular Complications in Chronic Kidney Disease

Chronic kidney disease (CKD) represents a significant global health challenge, affecting millions of individuals and leading to substantial morbidity and mortality. This review aims to explore the epidemiology, cardiovascular complications, and management strategies associated with CKD, emphasizing the importance of preventing cardiovascular disease and early intervention. CKD is primarily driven by conditions such as diabetes mellitus, hypertension, and cardiovascular diseases, which often coexist and exacerbate renal impairment. Effective management requires a multifaceted approach, including lifestyle modifications, pharmacological interventions, and regular monitoring. Dietary changes, such as sodium restriction and a controlled intake of phosphorus and potassium, play a vital role in preserving renal function. Pharmacological therapies, particularly angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and emerging agents like SGLT2 inhibitors, have shown efficacy in slowing disease progression and improving patient outcomes. Furthermore, patients undergoing dialysis face increased cardiovascular risk, necessitating comprehensive management strategies to address both renal and cardiac health. As the landscape of CKD treatment evolves, ongoing research into novel therapeutic options and personalized medical approaches are essential. This review underscores the urgent need for awareness, education, and effective preventive measures to mitigate the burden of CKD and enhance the quality of life for affected individuals.

Lead Acetate-Injected Mice is an Animal Model for Extrapolation of Calcifying Response to Humans Due to Low Involvement of Bone Resorption

Vascular calcification affects the prognosis of patients with renal failure. Bisphosphonates are regarded as candidate anti-calcifying drugs because of their inhibitory effects on both calcium-phosphate aggregation and bone resorption. However, calcification in well-known rodent models is dependent upon bone resorption accompanied by excessive bone turnover, making it difficult to estimate accurately the anti-calcifying potential of drugs. Therefore, models with low bone resorption are required to extrapolate anti-calcifying effects to humans. Three bisphosphonates (etidronate, alendronate, and FYB-931) were characterised for their inhibitory effects on bone resorption in vivo and calcium-phosphate aggregation estimated by calciprotein particle formation in vitro. Then, their effects were examined using two models inducing ectopic calcification: the site where lead acetate was subcutaneously injected into mice and the transplanted, aorta obtained from a donor rat. The inhibitory effects of bisphosphonates on bone resorption and calcium-phosphate aggregation were alendronate > FYB-931 > etidronate and FYB-931 > alendronate = etidronate, respectively. In the lead acetate-induced model, calcification was most potently suppressed by FYB-931, followed by alendronate and etidronate. In the aorta-transplanted model, only FYB-931 suppressed calcification at a high dose. In both the models, no correlation was observed between calcification and bone resorption marker, tartrate-resistant acid phosphatase (TRACP). Results from the lead acetate-induced model showed that inhibitory potency against calcium-phosphate aggregation contributed to calcification inhibition. The two calcification models, especially the lead acetate-induced model, may be ideal for the extrapolation of calcifying response to humans because of calcium-phosphate aggregation rather than bone resorption as its mechanism.

Bone and vascular effects of magnesium supplements in CKD patients (the MagicalBone Pilot Study)

BACKGROUND AND OBJECTIVE

The progression of chronic kidney disease (CKD) involves the development of alterations in mineral metabolism that are closely related to cardiovascular outcomes and bone disease. Hypomagnesemia is associated with more rapid progression of CKD and other comorbidities. Our objective was to analyze in CKD patients stages 3-4 the impact of the administration of magnesium (Mg) carbonate on bone mineral density (BMD) and hemodynamic changes associated with by vascular calcification (VC).

MATERIAL AND METHODS

Patients with CKD stages 3-4 were randomized into controls (n=12) or intervention (n=7) group receiving 360mg of Mg carbonate daily during a 15-month period. Parameters related to mineral metabolism, BMD, VC, and pulse wave velocity (PWV) were evaluated.

RESULTS

Supplementation with Mg produced an increase in the urinary excretion of Mg while serum Mg levels remained stable and no episodes of hypermagnesemia were reported. In addition, no significant changes were found in the degree of VC assessed by Adragao index, however, both serum and urine Mg were significantly associated with a decrease in PWV, suggesting an increase in vascular compliance. Likewise, BMD did not change following treatment, but serum Mg significantly correlated with the levels of N-terminal propeptide of collagen alpha-1(I) chain (PINP), a marker of bone synthesis.

CONCLUSIONS

In sum, these results suggest a possible beneficial effect of Mg on vascular compliance with no detrimental effects on bone status. In addition, our results highlight the need to consider monitorization of urinary Mg status in CKD patients.

Optic disc drusen: Dystrophic calcification, a potential target for treatment

Optic disc drusen (ODD) are calcified, acellular bodies, seen in the optic nerve head of up to 2% of the population. Although seldomly affecting visual acuity, visual field defects are common, and severe, ischemic complications causing irreversible vision loss are known to occur. Different treatment strategies for ODD have been explored, but so far without success. This review focuses on the unique, calcified property of ODD, describing what we know about ODD pathogenesis and previously tried treatment strategies. In this context, we discuss current knowledge about calcium and pathological calcifications, including intracranial and ocular calcifications. We also explore some of the obstacles that must be addressed to develop a therapy centred on the concept of calcification, should calcification be identified as a pathogenic factor contributing to vision loss.

Association of serum magnesium levels with renal prognosis in patients with chronic kidney disease

BACKGROUND

Magnesium deficiency is associated with various health conditions, but its impact on the progression of chronic kidney disease (CKD) remains unclear. This study aimed to investigate the association between serum magnesium levels and prognosis of renal function in CKD patients.

METHODS

This is an analysis of the Japan Chronic Kidney Disease Database Ex　(J-CKD-DB-Ex), which is a multicenter prospective cohort including CKD patients enrolled from January 1, 2014 to December 31, 2020. We included adult outpatients with CKD stage G3 and G4 at the time of initial magnesium measurement. Patients were classified by magnesium levels as low (<1.7 mg/dl), normal (1.7-2.6 mg/dl), or high (>2.6 mg/dl). The primary outcomes were the composite of an eGFR < 15 ml/min/1.73 m2 or a ≥30% reduction in eGFR from the initial measurement, which was defined as CKD progression. We applied the Kaplan-Meier analysis and Cox regression hazard model to examine the association between magnesium levels and CKD progression.

RESULTS

The analysis included 9868 outpatients during the follow-up period. The low magnesium group was significantly more likely to reach CKD progression. Cox regression, adjusting for covariates and using the normal magnesium group as the reference, showed that the hazard ratio for the low magnesium group was 1.20 (1.08-1.34). High magnesium was not significantly associated with poor renal outcomes compared with normal magnesium.

CONCLUSION

Based on large real-world data, this study demonstrated that low magnesium levels are associated with poorer renal outcomes.

Magnesium for disease treatment and prevention: emerging mechanisms and opportunities

Magnesium (Mg2+) is a commonly used dietary supplement for the prevention and treatment of diseases. However, the efficacy and mechanisms of action of Mg2+ in most diseases have been controversial because of conflicting findings in earlier studies. Recent clinical and preclinical studies provide novel insights into the use of Mg2+ for the treatment and prevention of diseases affecting different organ systems. In this review, we provide an overview of recent clinical evidence for, and controversies over, the medical benefits of Mg2+. In addition, we critically discuss recent advances in understanding the mechanisms of action of Mg2+, which could enable the development of novel targeted therapies.

Dietary magnesium supplementation in cats with chronic kidney disease: A prospective double-blind randomized controlled trial

BACKGROUND

Plasma total magnesium concentration (tMg) is a prognostic indicator in cats with chronic kidney disease (CKD), shorter survival time being associated with hypomagnesemia. Whether this risk factor is modifiable with dietary magnesium supplementation remains unexplored.

OBJECTIVES

Evaluate effects of a magnesium-enriched phosphate-restricted diet (PRD) on CKD-mineral bone disorder (CKD-MBD) variables.

ANIMALS

Sixty euthyroid client-owned cats with azotemic CKD, with 27 and 33 allocated to magnesium-enriched PRD or control PRD, respectively.

METHODS

Prospective double-blind, parallel-group randomized trial. Cats with CKD, stabilized on a PRD, without hypermagnesemia (tMg >2.43 mg/dL) or hypercalcemia (plasma ionized calcium concentration, (iCa) >6 mg/dL), were recruited. Both intention-to-treat and per-protocol (eating ≥50% of study diet) analyses were performed; effects of dietary magnesium supplementation on clinicopathological variables were evaluated using linear mixed effects models.

RESULTS

In the per-protocol analysis, tMg increased in cats consuming a magnesium-enriched PRD (β, 0.25 ± .07 mg/dL/month; P < .001). Five magnesium supplemented cats had tMg >2.92 mg/dL, but none experienced adverse effects. Rate of change in iCa differed between groups (P = .01), with decreasing and increasing trends observed in cats fed magnesium-enriched PRD and control PRD, respectively. Four control cats developed ionized hypercalcemia versus none in the magnesium supplemented group. Log-transformed plasma fibroblast growth factor-23 concentration (FGF23) increased significantly in controls (β, 0.14 ± .05 pg/mL/month; P = .01), but remained stable in the magnesium supplemented group (β, 0.05±.06 pg/mL/month; P =.37).

CONCLUSIONS AND CLINICAL IMPORTANCE

Magnesium-enriched PRD is a novel therapeutic strategy for managing feline CKD-MBD in cats, further stabilizing plasma FGF23 and preventing hypercalcemia.

Role of Magnesium, Effects of Hypomagnesemia, and Benefits of Magnesium Supplements in Cardiovascular and Chronic Kidney Diseases

Cardiovascular diseases (CVDs) account for nearly half of chronic kidney disease (CKD)-related deaths. Hypomagnesemia has been associated with various cardiovascular conditions and predicts a decline in renal function leading to end-stage renal disease (ESRD). The objective of this review is to delve into and discuss the significance of magnesium (Mg) in cardiovascular and renal functions, the clinical consequences of hypomagnesemia on CVD and CKD, and the benefits of Mg supplementation in managing CVD and CKD. This review is the result of an extensive search for pertinent articles in databases like PubMed, Medline, PubMed Central, and Google Scholar. Based on the literature search conducted in this review, we concluded that Mg protects against various CVDs and delays the progression of CKD. Mg can regulate pathways associated with inflammation, oxidative stress, and fibrosis. Therefore, maintaining slightly elevated Mg levels and timely Mg supplementation may benefit patients with CVD and CKD. There is a need for additional prospective randomized controlled trials to fully comprehend the therapeutic effects of Mg on CVD and CKD along with setting individualized target levels for serum Mg in such patients.

New therapeutic perspectives for vascular and valvular calcifications in chronic kidney disease

PURPOSE OF REVIEW

Vascular and valvular calcification are associated with cardiovascular morbidity and mortality in people with chronic kidney disease (CKD). Uncertainty exists regarding therapeutic strategies to attenuate calcification. This review outlines the pathophysiological mechanisms contributing to vascular and valvular calcification, considers the mechanisms of action of therapeutic interventions, and reports the latest outcomes from interventional studies.

RECENT FINDINGS

Conventional therapies targeted at CKD-mineral and bone disorder (MBD) modulation have yielded conflicting or inconclusive results. Magnesium and vitamin K supplementation appear to offer attenuation of coronary artery calcification but inconsistent findings justify the need for further studies. Strategies targeting hydroxyapatite formation such as sodium thiosulphate and hexasodium fytate show promise and are worthy of further evaluation. The serum calcification propensity assay (T50) correlates with severity and progression; it holds promise as a potential future clinical tool for screening monitoring calcification risk.

SUMMARY

Whilst knowledge of the pathophysiology of vascular calcification has grown and therapeutic approaches appear promising, as yet no medication has been approved to treat vascular or valvular calcification, or calciphylaxis.

Nephrology: What You May Have Missed in 2023

This article highlights a selection of important nephrology studies published in 2023 that have relevance for nonnephrologist physicians. Four studies examined progression of chronic kidney disease or cardiovascular disease with respect to finerenone use, magnesium supplementation, iron markers, and COVID-19. Two studies examined treatments to improve specific aspects of chronic kidney disease management, including daprodustat to address anemia and patiromer to address hyperphosphatemia. One study showed that acetazolamide added to loop diuretics increased diuresis in acute decompensated heart failure across a wide range of renal function. Another study found that once-daily hydrochlorothiazide did not prevent kidney stone recurrence. Finally, an antibiotic stewardship intervention safely reduced antibiotic prescribing for suspected urinary tract infection in frail older adults.

Associations of essential metals with the risk of aortic arch calcification: a cross-sectional study in a mid-aged and older population of Shenzhen, China

Vascular calcification is a strong predictor of cardiovascular events. Essential metals play critical roles in maintaining human health. However, the association of essential metal levels with risk of aortic arch calcification (AoAC) remains unclear. We measured the plasma concentrations of nine essential metals in a cross-sectional population and evaluated their individual and combined effects on AoAC risk using multiple statistical methods. We also explored the mediating role of fasting glucose. In the logistic regression model, higher quartiles of magnesium and copper were associated with the decreased AoAC risk, while higher quartile of manganese was associated with higher AoAC risk. The least absolute shrinkage and selection operator penalized regression analysis identified magnesium, manganese, calcium, cobalt, and copper as key metals associated with AoAC risk. The weighted quantile sum regression suggested a combined effect of metal mixture. A linear and positive dose-response relationship was found between manganese and AoAC in males. Moreover, blood glucose might mediate a proportion of 9.38% of the association between manganese exposure and AoAC risk. In summary, five essential metal levels were associated with AoAC and showed combined effect. Fasting glucose might play a significant role in mediating manganese exposure-associated AoAC risk.

Triglyceride-glucose index is an independent predictor of coronary artery calcification progression in patients with chronic kidney disease

BACKGROUND

Coronary artery calcification (CAC) is highly prevalent in patients with chronic kidney disease (CKD) and is associated with major adverse cardiovascular events and metabolic disturbances. The triglyceride-glucose index (TyGI), a novel surrogate marker of metabolic syndrome and insulin resistance, is associated with CAC in the general population and in patients with diabetes. This study investigated the association between the TyGI and CAC progression in patients with CKD, which is unknown.

METHODS

A total of 1,154 patients with CKD (grades 1-5; age, 52.8 ± 11.9 years; male, 688 [59.6%]) were enrolled from the KNOWCKD (KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease). The TyGI was calculated as follows: ln (fasting triglycerides × fasting glucose/2). Patients were classified into tertiles (low, intermediate, high) based on the TyGI. The primary outcome was annualized percentage change in CAC score [(percent change in CAC score + 1)12/follow-up months - 1] of ≥15%, defined as CAC progression.

RESULTS

During the 4-year follow-up, the percentage of patients with CAC progression increased across TyGI groups (28.6%, 37.5%, and 46.2% in low, intermediate, and high groups, respectively; p < 0.001). A high TyGI was associated with an increased risk of CAC progression (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.14-3.88; p = 0.02) compared to the low group. Moreover, a 1-point increase in the TyGI was related to increased risk of CAC progression (OR, 1.55; 95% CI, 1.06-1.76; p = 0.02) after adjustment.

CONCLUSION

A high TyGI may be a useful predictor of CAC progression in CKD.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Comparative Analysis of Vascular Calcification Risk Factors in Pre-Hemodialysis and Prevalent Hemodialysis Adult Patients: Insights into Calcification Biomarker Associations and Implications for Intervention Strategies in Chronic Kidney Disease

This retrospective study aimed to compare risk factors for vascular calcification (VC) between pre-hemodialysis (HD) and prevalent HD adult patients while investigating associations with calcification biomarkers. Baseline data from 30 pre-HD and 85 HD patients were analyzed, including iPTH, vitamin D, FGF 23, fetuin-A, sclerostin, and VC scores (Adragao method). Prevalence of VC was similar in both groups, but HD patients had more frequent VC scores ≥ 6. Pre-HD patients were older, with higher prevalence of hypertension and less frequent use of calcium phosphate binders. Both groups showed similar patterns of hyperphosphatemia, low vitamin D, and iPTH. Fetuin-A and sclerostin levels were higher in pre-HD, while FGF 23 was elevated in HD patients. Higher VC risk in pre-HD patients was associated with male gender, older age, lower fetuin-A and higher sclerostin, lower ferritin, and no vitamin D treatment, while in HD patients with higher sclerostin, FGF 23 and urea, and lower iPTH. Conclusion: Biomarkers could be measurable indicators of biological processes underlying VC in CKD patients that may serve as a potential guide for considering personalized therapeutic approaches. Further studies are needed to elucidate the underlying pathways.

Vascular calcification inhibitors and cardiovascular events in peritoneal dialysis patients

The prevalence of cardiovascular diseases is high among patients with chronic kidney disease (CKD) and peritoneal dialysis (PD) patients, which increases morbidity and mortality in this population and represents a significant financial burden for both the patients and the healthcare systems. Vascular calcification (VC) is associated with increased morbidity and mortality and VC risk is higher in patients with CKD than in healthy individuals. Calcification inhibitors, compounds that inhibit VC, were discovered as a result of efforts to explain why some patients are spared. It was found that certain proteins (e.g., fetuin-A, osteopontin, osteoprotegerin, bone morphogenetic protein-7) inhibit calcification in dialysis patients. In this narrative review, we provide an overview of known calcification inhibitors, describe the relevant regulatory mechanisms, and discuss their relation to VC development in PD patients.

Ionized and total magnesium levels in patients with chronic kidney disease: associated factors and outcomes

Background

The association between hypo- and/or hypermagnesaemia and cardiovascular (CV) outcomes or mortality has shown conflicting results in chronic kidney disease (CKD) and has been conducted on total magnesium (tMg) levels. Thus, the objectives of the present study were to (i) describe the serum ionized Mg (iMg) concentration in patients at various CKD stages, (ii) measure the correlation between iMg and tMg concentrations, (iii) identify their associated factors and (iv) determine whether serum tMg and/or iMg concentrations are associated with major adverse cardiovascular events (MACE) and mortality before kidney replacement therapy in CKD patients.

Methods

Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) is a prospective cohort of CKD patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Baseline iMg and tMg serum concentrations were centrally measured. Adjusted cause-specific Cox proportional hazard models were used to estimate hazard ratios (HRs) for first MACE and for mortality.

Results

Of the 2419 included patients, median age was 68 years, and the mean eGFR was 34.8 mL/min/1.73 m2. Concentrations of serum iMg and tMg were strongly correlated (r = 0.89, P < .001) and were independently associated with eGFR. The adjusted HR [95% confidence interval (CI)] for MACE associated with the baseline serum tMg level was 1.27 (0.95; 1.69) for patients in Tertile 1 and 1.56 (1.18; 2.06) for patients in Tertile 3, relative to patients in Tertile 2. The HR (95% CI) of death according to serum tMg concentration was increased in Tertile 3 [1.48 (1.11; 1.97)]. The adjusted risk for MACE and mortality (all-cause or CV) associated with the baseline serum iMg level was not significantly different between tertiles.

Conclusions

Our analysis of a large cohort of patients with moderate-to-advanced CKD demonstrated that individuals with higher serum tMg concentrations, although still within the normal range, had a greater likelihood of MACE and mortality. However, serum iMg levels were not associated with these outcomes.

Magnesium Is a Vital Ion in the Body-It Is Time to Consider Its Supplementation on a Routine Basis

The importance of maintaining proper magnesium intake and total body magnesium content in preserving human health remains underappreciated among medical professionals and laymen. This review aimed to show the importance of hypomagnesemia as a modifiable risk factor for developing disease processes. We searched the PubMed database and Google Scholar using the keywords 'magnesium', 'diabetes', 'cardiovascular disease', 'respiratory disease', 'immune system', 'inflammation', 'autoimmune disease', 'neurology', 'psychiatry', 'cognitive function', 'cancer', and 'vascular calcification'. In multiple contexts of the search terms, all reviews, animal experiments, and human observational data indicated that magnesium deficiency can lead to or contribute to developing many disease states. The conclusions of several in-depth reviews support our working hypothesis that magnesium and its supplementation are often undervalued and underutilized. Although much research has confirmed the importance of proper magnesium supply and tissue levels, simple and inexpensive magnesium supplementation has not yet been sufficiently recognized or promoted.

Differential associations of fetuin-A and calcification propensity with cardiovascular events and subsequent mortality in patients undergoing hemodialysis

Background

Fetuin-A inhibits precipitation of calcium-phosphate crystals by forming calciprotein particles (CPP). A novel T50 test, which measures transformation time from primary to secondary CPP, is an index for calcification propensity. Both lower fetuin-A and shorter T50 levels were associated with cardiovascular disease (CVD) risk in patients with chronic kidney disease (CKD). Extremely high risk for CVD death in advanced CKD patients consists of high-incidental CVD event and high mortality after CVD event. To date, it is unclear whether fetuin-A and/or T50 can equally predict each CVD outcome.

Methods

This prospective cohort study examined patients undergoing maintenance hemodialysis. The exposures were fetuin-A and T50. The outcomes of interests were new CVD events and subsequent deaths. The patients were categorized into tertiles of fetuin-A or T50 (T1 to T3).

Results

We identified 190 new CVD events during the 5-year follow-up of the 513 patients and 59 deaths subsequent to the CVD events during 2.5-year follow-up. A lower fetuin-A but not T50 was significantly associated with new CVD events [subdistribution hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.15-2.61, P = .009 for T1 vs T3]. In contrast, a shorter T50 but not fetuin-A was a significant predictor of deaths after CVD events (HR 3.31, 95% CI 1.42-7.74, P = .006 for T1 + T2 vs T3). A lower fetuin-A was predictive of new CVD events, whereas a shorter T50 was more preferentially associated with subsequent death.

Conclusion

These results indicate that fetuin-A and T50 are involved in cardiovascular risk in different manners.

Food to Prevent Vascular Calcification in Chronic Kidney Disease

Vascular calcification (VC) is a consequence of chronic kidney disease (CKD) which is of paramount importance regarding the survival of CKD patients. VC is far from being controlled with actual medication; as a result, in recent years, diet modulation has become more compelling. The concept of medical nutritional therapy points out the idea that food may prevent or treat diseases. The aim of this review was to evaluate the influence of food habits and nutritional intervention in the occurrence and progression of VC in CKD. Evidence reports the harmfulness of ultra-processed food, food additives, and animal-based proteins due to the increased intake of high absorbable phosphorus, the scarcity of fibers, and the increased production of uremic toxins. Available data are more supportive of a plant-dominant diet, especially for the impact on gut microbiota composition, which varies significantly depending on VC presence. Magnesium has been shown to prevent VC but only in experimental and small clinical studies. Vitamin K has drawn considerable attention due to its activation of VC inhibitors. There are positive studies; unfortunately, recent trials failed to prove its efficacy in preventing VC. Future research is needed and should aim to transform food into a medical intervention to eliminate VC danger in CKD.

Multicentre, open-label, randomised, controlled trial to compare early intervention with calcimimetics and conventional therapy in preventing coronary artery calcification in patients with secondary hyperparathyroidism (UPCOMING): a study protocol

INTRODUCTION

Coronary artery and heart valve calcification is a risk factor for cardiovascular death in haemodialysis patients, so calcification prevention should be started as early as possible. Treatment with concomitant calcimimetics and low-dose vitamin D receptor activators (VDRAs) is available, but not enough evidence has been obtained on the efficacy of this regimen, particularly in patients with short dialysis duration. Therefore, this study will evaluate the efficacy and safety of early intervention with upacicalcet, a calcimimetic used to prevent coronary artery calcification in this patient population.

METHODS AND ANALYSIS

This multicentre, open-label, randomised, parallel-group controlled study will compare an early intervention group, which received upacicalcet and a low-dose VDRA, with a conventional therapy group, which received a VDRA. The primary endpoint is a change in log coronary artery calcium volume score from baseline to 52 weeks. The main inclusion criteria are as follows: (1) age 18 years or older; (2) dialysis is planned or dialysis duration is less than 60 months; (3) intact parathyroid hormone (PTH) >240 pg/mL or whole PTH level>140 pg/mL; (4) serum-corrected calcium≥8.4 mg/dL and (5) Agatston score >30. The main exclusion criteria are as follows: (1) history of parathyroid intervention or fracture in the past 12 weeks; (2) history of myocardial infarction, stroke or leg amputation in the past 12 weeks; (3) history of coronary angioplasty and (4) heart failure of New York Heart Association class III or worse.

ETHICS AND DISSEMINATION

The study will comply with the Declaration of Helsinki and the Japanese Clinical Trials Act. The study protocol has been approved by the Fujita Health University Certified Review Board (file no. CR22-052). Written informed consent will be obtained from all participants. Study results will be presented in academic meetings and peer-reviewed academic journals.

TRIAL REGISTRATION NUMBER

jRCTs041220126.

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.

Phosphate and Coronary Artery Disease in Patients with Chronic Kidney Disease

Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD). Both traditional and CKD-related factors are associated with CVD in CKD patients. Traditional factors that play an important role in the atherosclerotic process directly contribute to a higher risk of coronary artery disease in patients with early-stage CKD. Among CKD-related factors, CKD-mineral and bone disorder plays a critical role in the pathomechanism of nonatherosclerotic diseases, which increases the risk of cardiovascular morbidity and mortality in patients with advanced CKD. Higher serum phosphate levels were significantly associated with cardiovascular events and all-cause mortality in patients with or without CKD. An increased phosphate load, directly and indirectly, promotes arterial medial calcification and left ventricular hypertrophy, both of which predispose patients to coronary artery disease. Calciprotein particles that form in a hyperphosphatemic state promote the transformation of vascular smooth muscle cells (VSMCs) into osteoblastic cells, thereby providing a scaffold for medial calcification in the artery. Increases in fibroblast growth factor-23 and disturbed vitamin D metabolism induced by an excessive phosphate load play a significant role in the development of cardiomyocyte hypertrophy and cardiac fibrosis. Recently, hyperphosphatemia was reported to promote de novo cholesterol synthesis in VSMCs and macrophages, which is likely to contribute to statin resistance in patients with end-stage kidney disease. This review outlines the association between increased phosphate load and coronary artery disease in patients with CKD.

Effect of magnesium on vascular calcification in chronic kidney disease patients: a systematic review and meta-analysis

PURPOSE

To evaluate the effects of magnesium (Mg) supplementation on vascular calcification (VC) in patients with chronic kidney disease (CKD).

METHODS

PubMed, Embase, Cochrane Library, Medline, Web of Science, CNKI, VIP, and WanFang databases were searched from build to July 2022. Randomized controlled trials (RCT) and non-RCT related to whether Mg supplementation inhibits VC in patients with CKD were included. The literature was screened according to inclusion and exclusion criteria, and quality evaluation and data collection were performed. Meta-analysis was performed using Review Manager 5.4 software.

RESULTS

8 RCTs and 1 non-RCT studies with a total of 496 patients were eventually included. Compared to control groups, Mg supplementation increased serum Mg levels (SMD = 1.26, 95% CI: -0.70 to 1.82, p < 0.001), but it was not statistically significant in alleviating the degree of VC, increasing T50, and reducing serum phosphorus (P) levels in patients with CKD (all p > 0.05). Oral Mg reduced left (WMD=-0.06, 95% CI. -0.11 to -0.01, p = 0.03) and right (WMD=-0.07, 95% CI: -0.13 to -0.01, p = 0.02) carotid intima-media thickness (cIMT). Additionally, calcium (Ca) (SMD=-0.43, 95% CI: -0.74 to -0.11, p = 0.008) and parathyroid hormone (PTH) (SMD=-0.43, 95% CI: -0.75 to -0.11, p = 0.008) levels were reduced by increasing dialysate Mg concentration.

CONCLUSIONS

Mg supplementation increased serum Mg levels and reduced Ca, PTH, and cIMT, but it did not reduce VC scores in patients with CKD. This still requires further studies with larger samples to evaluate the effect of Mg supplementation on VC.

Hypomagnesemia: a potential underlooked cause of persistent vitamin D deficiency in chronic kidney disease

Magnesium and vitamin D play important roles in most cells of the body. These nutrients act in a coordinated fashion to maintain physiologic functions of various organs, and their abnormal balance could adversely affect these functions. Therefore, deficient states of both nutrients may lead to several chronic medical conditions and increased cardiovascular and all-cause mortality. Chronic kidney disease (CKD) patients have altered metabolism of both magnesium and vitamin D. Some studies indicate that magnesium could have a role in the synthesis and metabolism of vitamin D, and that magnesium supplementation substantially reversed the resistance to vitamin D treatment in some clinical situations. Recent observational studies also found that magnesium intake significantly interacted with vitamin D status and, particularly with the risk of cardiovascular mortality. It is therefore essential to ensure adequate levels of magnesium to obtain the optimal benefits of vitamin D supplementation in CKD patients. In this review, we discuss magnesium physiology, magnesium and vitamin D metabolism in CKD, potential metabolic interactions between magnesium and vitamin D and its clinical relevance, as well as the possible role of magnesium supplementation to assure adequate vitamin D levels.

Regulatory effects of nutritional and metabolic disorders on vascular calcification in chronic kidney disease: a narrative review

Background and Objective

Vascular calcification (VC) is common in chronic kidney disease (CKD) patients and is associated with poor cardiovascular outcomes. This study aims to review nutritive pro-calcifying factors of CKD.

Methods

Electronic databases (PubMed, Embase, and the Cochrane Central Register of Controlled Trials) were searched from 2001 as at July 26, 2022, to select and summarize the basic and clinical studies reporting the effects of malnutrition or metabolic disorders on VC in CKD and the evolving treatments for these nutrient metabolic disorders.

Key Content and Findings

Hyperphosphatemia, calcium load, hypomagnesemia, iron deficiency, lipoprotein(a) abnormalities, protein malnutrition, and vitamin K deficiency secondary to CKD were closely associated with the occurrence and development of VC. Elevated phosphate and calcium levels were essential contributors to VC, yet current phosphate binders with good phosphate-lowering effects had not been shown to delay VC progression in CKD, and it remained challenging on how to identify and prevent calcium overload. Magnesium supplementation was the most promising treatment for mitigating VC, as supported by in vitro and in vivo studies and clinical trials. Correction of iron and vitamin K deficiency might contribute to VC attenuation, yet there was a lack of clinical evidence on CKD patients.

Conclusions

This review highlighted the effects of nutrient metabolism disorders on CKD-VC, and additional studies are needed to further address optimal nutrition strategies for mitigating VC in CKD.

The Role of Plant-Based Diets in Preventing and Mitigating Chronic Kidney Disease: More Light than Shadows

Chronic kidney disease (CKD) is a non-communicable disease that affects >10% of the general population worldwide; the number of patients affected by CKD is increasing due in part to the rise in risk factors such as obesity, hypertension, and diabetes mellitus. As many studies show, diet can be an important tool for preventing and mitigating the onset of non-communicable diseases. Plant-based diets (PBDs) are those that emphasize the consumption of plant foods and may or may not include small or moderate amounts of animal foods. Recently, these diets have received increasing interest because they have been associated with favourable effects on health and also appear to protect against the development and progression of CKD. PBDs, which are associated with protein restrictions, seem to offer adjunctive advantages in patients with chronic kidney disease, as compared to conventional low-protein diets that include animal proteins. The principal aims of this review are to provide a comprehensive overview of the existing literature regarding the role of plant-based diets and low-protein, plant-based diets in the context of chronic kidney disease. Moreover, we try to clarify the definition of plant-based diets, and then we analyse possible concerns about the use of PBDs in patients with chronic kidney disease (nutritional deficiency and hyperkalaemia risk). Finally, we offer some strategies to increase the nutritional value of plant-based low-protein diets. In the Materials and Methods section, many studies about plant-based diets and low-protein plant-based diets (e.g., the very-low-protein diet and vegan low-protein diet, LPD) in chronic kidney disease were considered. In the Results and Conclusion section, current data, most from observational studies, agree upon the protective effect of plant-based diets on kidney function. Moreover, in patients with advanced CKD, low-protein plant-based options, especially a very-low-protein diet supplemented with heteroanalogues (VLPDs), compared to a conventional LPD appear to offer adjunctive advances in terms of delaying dialysis and mitigating metabolic disturbances. However, further studies are necessary to better investigate the possible metabolic and cardiovascular advantages of plant-based LPDs versus conventional LPDs.

Removal of calciprotein particles from the blood using an adsorption column improves prognosis of hemodialysis miniature pigs

Hyperphosphatemia is a major risk for poor prognosis in patients with end-stage renal disease. However, the molecular mechanism behind this link remains elusive. We and others have demonstrated that serum phosphorus levels correlate positively with circulating levels of calciprotein particles (CPPs). CPPs are colloidal mineral-protein complexes containing insoluble calcium-phosphate precipitates and have been reported to induce calcification in cultured vascular smooth muscle cells and inflammatory responses in cultured macrophages. Hence, we hypothesize that CPPs may be responsible for disorders associated with hyperphosphatemia. Using hyperphosphatemic miniature pigs receiving hemodialysis, here we show that removal of CPPs from the blood with a newly developed CPP adsorption column improves survival and alleviates complications including coronary artery calcification, vascular endothelial dysfunction, metastatic pulmonary calcification, left ventricular hypertrophy, and chronic inflammation. The present study identifies CPPs as an effective therapeutic target and justifies clinical trials to determine whether the CPP adsorption column may be useful as a medical device for improving clinical outcomes of hemodialysis patients.

Calcium phosphate microcrystallopathy as a paradigm of chronic kidney disease progression

PURPOSE OF REVIEW

Calciprotein particles (CPP) are colloidal mineral-protein complexes mainly composed of solid-phase calcium phosphate and serum protein fetuin-A. CPP appear in the blood and renal tubular fluid after phosphate intake, playing critical roles in (patho)physiology of mineral metabolism and chronic kidney disease (CKD). This review aims at providing an update of current knowledge on CPP.

RECENT FINDINGS

CPP formation is regarded as a defense mechanism against unwanted growth of calcium phosphate crystals in the blood and urine. CPP are polydisperse colloids and classified based on the density and crystallinity of calcium phosphate. Low-density CPP containing amorphous (noncrystalline) calcium phosphate function as an inducer of FGF23 expression in osteoblasts and a carrier of calcium phosphate to the bone. However, once transformed to high-density CPP containing crystalline calcium phosphate, CPP become cytotoxic and inflammogenic, inducing cell death in renal tubular cells, calcification in vascular smooth muscle cells, and innate immune responses in macrophages.

SUMMARY

CPP potentially behave like a pathogen that causes renal tubular damage, chronic inflammation, and vascular calcification. CPP have emerged as a promising therapeutic target for CKD and cardiovascular complications.

Serum Magnesium Levels and Cardiovascular Outcomes in Systolic Blood Pressure Intervention Trial Participants

Rationale and Objective

Serum magnesium levels have been inversely yet inconsistently associated with cardiovascular (CV) outcomes. In this study, we examined the association of serum magnesium levels with CV outcomes in the Systolic Blood Pressure Intervention Trial (SPRINT) participants.

Study Design

Case-control post hoc analysis of SPRINT.

Setting & Participants

A total of 2,040 SPRINT participants with available serum samples at baseline level were included in this study. Case participants (n = 510) who experienced a CV event during the SPRINT observation period (median follow-up of 3.2 years) and control participants (n = 1,530) without CV events were sampled in a 1:3 ratio for measurements of serum magnesium level at baseline and 2-year follow-up.

Predictors

Baseline serum magnesium levels and 2-year percentage change in serum magnesium levels (ΔSMg).

Outcome

SPRINT primary composite CV outcome.

Analytical Approach

Multivariable conditional logistic regression analysis, accounting for matching factors, was used to evaluate the association of baseline and ΔSMg with CV outcomes. Individual matching of cases and controls was based on the SPRINT treatment arm allocation (standard vs intensive) and prevalence of chronic kidney disease (CKD).

Results

The median serum magnesium level at baseline was similar among the case and control groups. In a fully adjusted model, each standard deviation (SD) (0.18 mg/dL) higher of the baseline serum magnesium level was independently associated with a lower risk for composite CV outcomes in all study participants (adjusted odds ratio 95% CI, 0.79 [0.70-0.89]). This association was similar when serum magnesium levels were analyzed in quartiles but dissipated in the standard (vs intensive) arm of SPRINT (0.88 [0.76-1.02] vs 0.65 [0.53-0.79], respectively; Pinteraction = 0.06). The presence or absence of CKD at baseline did not modify this association. ΔSMg was not independently associated with CV outcomes occurring after 2 years.

Limitations

ΔSMg was small in magnitude, limiting effect size.

Conclusions

Higher baseline serum magnesium levels were independently associated with reduced risk for CV outcomes in all study participants, but ΔSMg was not associated with CV outcomes.

Pathophysiology and Clinical Impacts of Chronic Kidney Disease on Coronary Artery Calcification

The global prevalence of chronic kidney disease (CKD) has increased in recent years. Adverse cardiovascular events have become the main cause of life-threatening events in patients with CKD, and vascular calcification is a risk factor for cardiovascular disease. Vascular calcification, especially coronary artery calcification, is more prevalent, severe, rapidly progressive, and harmful in patients with CKD. Some features and risk factors are unique to vascular calcification in patients with CKD; the formation of vascular calcification is not only influenced by the phenotypic transformation of vascular smooth muscle cells, but also by electrolyte and endocrine dysfunction, uremic toxin accumulation, and other novel factors. The study on the mechanism of vascular calcification in patients with renal insufficiency can provide a basis and new target for the prevention and treatment of this disease. This review aims to illustrate the impact of CKD on vascular calcification and to discuss the recent research data on the pathogenesis and factors involved in vascular calcification, mainly focusing on coronary artery calcification, in patients with CKD.

Plasma metallomics reveals potential biomarkers and insights into the ambivalent associations of elements with acute myocardial infarction

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Using a validated and efficient ICP-MS/MS-based workflow, a total of 30 metallomic features were profiled in a study comprising 101 AMI patients and 66 age-matched healthy controls. The metallomic features include 12 essential elements (Ca, Co, Cu, Fe, K, Mg, Mn, Na, P, S, Se, Zn), 8 non-essential/toxic elements (Al, As, Ba, Cd, Cr, Ni, Rb, Sr, U, V), and 10 clinically relevant element-pair product/ratios (Ca/Mg, Ca×P, Cu/Se, Cu/Zn, Fe/Cu, P/Mg, Na/K, Zn/Se). Preliminary linear regression with feature selection confirmed smoking status as a predominant determinant for the non-essential/toxic elements, and revealed potential routes of action. Univariate assessments with adjustments for covariates revealed insights into the ambivalent relationships of Cu, Fe, and P with AMI, while also confirming cardioprotective associations of Se. Also, beyond their roles as risk factors, Cu and Se may be involved in the response mechanism in AMI onset/intervention, as demonstrated via longitudinal data analysis with 2 additional time-points (1-/6-month follow-up). Finally, based on both univariate tests and multivariate classification modelling, potentially more sensitive markers measured as element-pair ratios were identified (e.g., Cu/Se, Fe/Cu). Overall, metallomics-based biomarkers may have utility for AMI prediction.

The Effect of Magnesium Supplementation on Vascular Calcification in CKD: A Randomized Clinical Trial (MAGiCAL-CKD)

SIGNIFICANCE STATEMENT

Magnesium prevents vascular calcification in animals with CKD. In addition, lower serum magnesium is associated with higher risk of cardiovascular events in CKD. In a randomized, double-blinded, placebo-controlled trial, the authors investigated the effects of magnesium supplementation versus placebo on vascular calcification in patients with predialysis CKD. Despite significant increases in plasma magnesium among study participants who received magnesium compared with those who received placebo, magnesium supplementation did not slow the progression of vascular calcification in study participants. In addition, the findings showed a higher incidence of serious adverse events in the group treated with magnesium. Magnesium supplementation alone was not sufficient to delay progression of vascular calcification, and other therapeutic strategies might be necessary to reduce the risk of cardiovascular disease in CKD.

BACKGROUND

Elevated levels of serum magnesium are associated with lower risk of cardiovascular events in patients with CKD. Magnesium also prevents vascular calcification in animal models of CKD.

METHODS

To investigate whether oral magnesium supplementation would slow the progression of vascular calcification in CKD, we conducted a randomized, double-blinded, placebo-controlled, parallel-group, clinical trial. We enrolled 148 subjects with an eGFR between 15 and 45 ml/min and randomly assigned them to receive oral magnesium hydroxide 15 mmol twice daily or matching placebo for 12 months. The primary end point was the between-groups difference in coronary artery calcification (CAC) score after 12 months adjusted for baseline CAC score, age, and diabetes mellitus.

RESULTS

A total of 75 subjects received magnesium and 73 received placebo. Median eGFR was 25 ml/min at baseline, and median baseline CAC scores were 413 and 274 in the magnesium and placebo groups, respectively. Despite plasma magnesium increasing significantly during the trial in the magnesium group, the baseline-adjusted CAC scores did not differ significantly between the two groups after 12 months. Prespecified subgroup analyses according to CAC>0 at baseline, diabetes mellitus, or tertiles of serum calcification propensity did not significantly alter the main results. Among subjects who experienced gastrointestinal adverse effects, 35 were in the group receiving magnesium treatment versus nine in the placebo group. Five deaths and six cardiovascular events occurred in the magnesium group compared with two deaths and no cardiovascular events in the placebo group.

CONCLUSIONS

Magnesium supplementation for 12 months did not slow the progression of vascular calcification in CKD, despite a significant increase in plasma magnesium.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov ( NCT02542319 ).

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

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.

Possible contribution of phosphate to the pathogenesis of chronic kidney disease in dolphins

This study aimed to investigate whether phosphate contributes to the pathogenesis of chronic kidney disease (CKD) in dolphins. Renal necropsy tissue of an aged captive dolphin was analyzed and in vitro experiments using cultured immortalized dolphin proximal tubular (DolKT-1) cells were performed. An older dolphin in captivity died of myocarditis, but its renal function was within the normal range until shortly before death. In renal necropsy tissue, obvious glomerular and tubulointerstitial changes were not observed except for renal infarction resulting from myocarditis. However, a computed tomography scan showed medullary calcification in reniculi. Micro area X-ray diffractometry and infrared absorption spectrometry showed that the calcified areas were primarily composed of hydroxyapatite. In vitro experiments showed that treatment with both phosphate and calciprotein particles (CPPs) resulted in cell viability loss and lactate dehydrogenase release in DolKT-1 cells. However, treatment with magnesium markedly attenuated this cellular injury induced by phosphate, but not by CPPs. Magnesium dose-dependently decreased CPP formation. These data support the hypothesis that continuous exposure to high phosphate contributes to the progression of CKD in captive-aged dolphins. Our data also suggest that phosphate-induced renal injury is mediated by CPP formation in dolphins, and it is attenuated by magnesium administration.

Citric acid-based bicarbonate dialysate attenuates aortic arch calcification in maintenance hemodialysis patients: a retrospective observational study

BACKGROUND

Progression of aortic calcification is associated with all-cause and cardiovascular mortality in hemodialysis patients. Blood calciprotein particle (CPP) levels are associated with coronary artery calcification and were reported to be inhibited when using citric acid-based bicarbonate dialysate (CD). Therefore, this study aimed to examine the effect of CD on the progression of the aortic arch calcification score (AoACS) and blood CPP levels in hemodialysis patients.

METHODS

A 12-month retrospective observational study of 262 hemodialysis patients was conducted. AoACS was evaluated by calculating the number of calcifications in 16 segments of the aortic arch on chest X-ray (minimum score is 0; maximum score is 16 points). The patients were divided into the following groups according to their baseline AoACS: grade 0, AoACS = 0 points; grade 1, AoACS 1-4 points; grade 2, AoACS 5-8 points; grade 3, AoACS 9 points or higher. Patients on bisphosphonates or warfarin or with AoACS grade 3 were excluded. Progression, defined as ΔAoACS (12-month score - baseline score) > 0 points, was compared between the CD and acetic acid-based bicarbonate dialysate (AD) groups before and after adjusting the background using propensity score matching.

RESULTS

The AoACS progression rate was significantly lower in the CD group than in the AD group (before matching: P = 0.020, after matching: P = 0.002). Multivariate logistic regression analysis showed that CD was significantly associated with AoACS progression (odds ratio 0.52, 95% confidence interval 0.29‒0.92, P = 0.025).

CONCLUSION

CD may slow the progression of vascular calcification in hemodialysis patients.

Plant-Dominant Low Protein Diet: A Potential Alternative Dietary Practice for Patients with Chronic Kidney Disease

Dietary protein restriction has long been a cornerstone of nutritional therapy for patients with chronic kidney diseases (CKD). However, the recommended amount of dietary protein intake is different across guidelines. This is partly because previous randomized controlled trials have reported conflicting results regarding the efficacy of protein restriction in terms of kidney outcomes. Interestingly, a vegetarian, very low protein diet has been shown to reduce the risk of kidney failure among patients with advanced CKD, without increasing the incidence of hyperkalemia. This finding suggests that the source of protein may also influence the kidney outcomes. Furthermore, a plant-dominant low-protein diet (PLADO) has recently been proposed as an alternative dietary therapy for patients with CKD. There are several potential mechanisms by which plant-based diets would benefit patients with CKD. For example, plant-based diets may reduce the production of gut-derived uremic toxins by increasing the intake of fiber, and are useful for correcting metabolic acidosis and hyperphosphatemia. Plant proteins are less likely to induce glomerular hyperfiltration than animal proteins. Furthermore, plant-based diets increase magnesium intake, which may prevent vascular calcification. More evidence is needed to establish the efficacy, safety, and feasibility of PLADO as a new adjunct therapy in real-world patients with CKD.

The pathophysiology and management of vascular calcification in chronic kidney disease patients

INTRODUCTION

Vascular calcification (VC) which is the pathological mineral deposition in the vascular system, predominantly at the intimal and medial layer of the vessel wall, is an important comorbidity in patients with chronic kidney disease (CKD) leading to significant morbidity and mortality while necessitating appropriate treatment. Our review aims to provide an in-depth analysis of the current understanding of VC.

AREAS COVERED

In this review, we first discuss the pathophysiology of VC in CKD patients, then we explain the methods to predict and assess VC. Afterwards, we provide the currently available as well as the potential therapeutic approaches of VC. We finally discuss our understanding regarding the current situation surrounding VC in our expert opinion section.

EXPERT OPINION

Predicting, assessing and treating VC is crucial and the future advances in the field of research surrounding VC will potentially occur in one or more of these three areas of clinical management. There is a current lack of evidence and consensus regarding specific therapeutic options for alleviating VC and this situation may not necessitate VC to be determined, detected, and documented before the available options are implemented. Regardless, the prediction and assessment of VC is still important and requires further improvement together with the developments in therapeutic alternatives. The future has the potential to bring better research which would guide and improve the management of this patient group. A more specialized approach consisting of targeted therapies and more tailored management plans for patients with CKD and VC is on the horizon.

Magnesium Administration in Chronic Kidney Disease

Awareness of the clinical relevance of magnesium in medicine has increased over the last years, especially for people with chronic kidney disease (CKD), due to magnesium's role in vascular calcification and mineral metabolism. The inverse association between serum magnesium and clinically relevant, adverse outcomes is well-established in people with CKD. Subsequent intervention studies have focused on the effect of magnesium administration, mainly in relation to cardiovascular diseases, mineral bone metabolism, and other metabolic parameters. The most commonly used routes of magnesium administration are orally and by increasing dialysate magnesium. Several oral magnesium formulations are available and the daily dosage of elemental magnesium varies highly between studies, causing considerable heterogeneity. Although data are still limited, several clinical studies demonstrated that magnesium administration could improve parameters of vascular function and calcification and mineral metabolism in people with CKD. Current clinical research has shown that magnesium administration in people with CKD is safe, without concerns for severe hypermagnesemia or negative interference with bone metabolism. It should be noted that there are several ongoing magnesium intervention studies that will contribute to the increasing knowledge on the potential of magnesium administration in people with CKD.

Preoperative hypomagnesemia as a possible predictive factor for postoperative increase of transvalvular pressure gradient in hemodialysis patients treated with transcatheter aortic valve implantation

BACKGROUND

Patients undergoing maintenance hemodialysis (HD) with severe aortic stenosis are at a high risk for bioprosthetic valve dysfunction after transcatheter aortic valve implantation (TAVI). Currently, preoperative factors that predict the occurrence of valve dysfunction after TAVI on HD patients remain to be elucidated. The aim of this study is to analyze the association between preoperative clinical factors and valve stenosis after TAVI on HD patients.

METHODS

Twenty-four of HD patients who underwent TAVI at our institution between April 2012 and January 2016 were analyzed. The mean aortic transvalvular pressure gradient (MPG) and effective orifice area index (EOAi) were assessed by serial echocardiography. Associations between preoperative clinical factors and time-series changes in MPG were examined using mixed-effects linear regression model for repeated measures.

RESULTS

Three patients developed severe structural valve deterioration with calcific valve stenosis requiring reoperation. A multivariate linear mixed-effects model showed that lower serum magnesium (sMg) levels were associated with the increase of MPG after TAVI (beta-coefficient = 0.019, p = 0.03). No correlation was observed with serum calcium, phosphorus, or intact parathyroid hormone. Time-series changes of MPG and EOAi had significant difference between lower and higher sMg group. All 3 of the patients who underwent reoperation showed lower preoperative sMgs.

CONCLUSION

Among bone-mineral metabolism markers, preoperative hypomagnesemia was associated with the increase of MPG after TAVI, suggesting that hypomagnesemia could predict post-TAVI valve dysfunction in HD patients. Further studies with larger sample sizes are warranted.