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

A Comprehensive Review on Understanding Magnesium Disorders: Pathophysiology, Clinical Manifestations, and Management Strategies

Magnesium is vital in a broad spectrum of physiological processes, including enzyme activity, energy production, and neuromuscular function. Despite its crucial role, magnesium disorders - comprising both deficiency (hypomagnesemia) and excess (hypermagnesemia) - are frequently underrecognized and inadequately managed in clinical practice. Magnesium deficiency is widespread, particularly among populations with chronic illnesses, the elderly, and those experiencing malnutrition, often leading to significant neuromuscular, cardiovascular, and metabolic complications. Conversely, hypermagnesemia, though less common, poses serious risks, especially in individuals with impaired renal function or those receiving high doses of magnesium supplements or medications. This review comprehensively examines magnesium disorders, detailing their pathophysiology, clinical manifestations, and management strategies. It highlights the essential functions of magnesium in maintaining cellular integrity, cardiovascular health, and bone structure and discusses the global prevalence and risk factors associated with magnesium imbalances. By offering insights into the current understanding of magnesium homeostasis and its disruptions, this review aims to enhance the awareness and treatment of magnesium-related conditions, ultimately improving patient outcomes across diverse clinical settings.

Understanding the Korean Dialysis Cohort for Mineral, Vascular Calcification, and Fracture (ORCHESTRA) Study: Design, Method, and Baseline Characteristics

INTRODUCTION

End-stage renal disease (ESRD) is a growing disease worldwide, including Korea. This is an important condition that affects patient outcome. To provide optimal management for mineral disturbance, vascular calcification, and bone disease in ESRD patients, the Korean dialysis cohort for mineral, vascular calcification, and fracture (ORCHESTRA) study was conducted by enrolling Korean dialysis patients.

METHODS

Sixteen university-affiliated hospitals and one Veterans' Health Service Medical Center participated in this study. This prospective cohort study enrolled approximately 900 consecutive patients on dialysis between May 2019 and January 2021. Enrolled subjects were evaluated at baseline for demographic information, laboratory tests, radiologic imaging, and bone mineral densitometry (BMD) scans. After enrollment, regular assessments of the patients were performed, and their biospecimens were collected according to the study protocol. The primary outcomes were the occurrence of major adverse cardiovascular events, invasive treatment for peripheral artery disease, and osteoporotic fractures. The secondary outcomes were hospitalization for cerebrovascular disease or progression of abdominal aortic calcification. Participants will be assessed for up to 3 years to determine whether primary or secondary outcomes occur.

RESULTS

Between May 2019 and January 2021, all participating centers recruited 900 consecutive dialysis patients, including 786 undergoing hemodialysis (HD) and 114 undergoing peritoneal dialysis (PD). The mean age of the subjects was 60.4 ± 12.3 years. Males accounted for 57.7% of the total population. The mean dialysis vintage was 6.1 ± 6.0 years. The HD group was significantly older, had a longer dialysis vintage, and more comorbidities. Overall, the severity of vascular calcification was higher and the level of BMD was lower in the HD group than in the PD group.

CONCLUSION

This nationwide, multicenter, prospective cohort study focused on chronic kidney disease-mineral and bone disorder and aimed to provide clinical evidence to establish optimal treatment guidelines for Asian dialysis patients.

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.

Association of Serum Magnesium with Gastrointestinal Bleeding in Peritoneal Dialysis Patients: a Multicentre Retrospective Study

Serum magnesium is involved in the process of blood coagulation, and low serum magnesium is associated with haemorrhagic diseases. No studies have explored the relationship between serum magnesium and gastrointestinal bleeding (GIB). This study aimed to explore the association between serum magnesium and GIB in peritoneal dialysis (PD) patients. This was a multicentre retrospective cohort study. The primary endpoint was GIB. According to the baseline serum magnesium level of 0.7 mmol/L, patients were divided into two groups: the hypomagnesaemia group and the nonhypomagnesaemia group. A multivariate Cox regression model was used to investigate the association between hypomagnesaemia and GIB. A total of 654 PD patients from four Chinese peritoneal dialysis centres were recruited from February 1, 2010 to January 31, 2020. During the follow-up, 47 patients experienced GIB. Kaplan-Meier curves showed that there was a significant difference in the risk of GIB between the two groups (log-rank = 11.82, P < 0.001). The multivariable Cox regression model showed that the risk of GIB was higher in the hypomagnesaemia group than the nonhypomagnesaemia group after adjustment for demographic variables and laboratory indicators (HR = 3.007, 95% CI 1.488-6.079, P = 0.002). A baseline lower serum magnesium level was associated with a higher risk of GIB in PD patients.

Influencing factors of serum magnesium in CKD5 patients: A multicenter study in southern China

INTRODUCTION

Magnesium (Mg) disturbances are related to cardiac, bone, and renal patient mortality. In this study, we compared biochemical markers in hemodialysis (HD) and peritoneal dialysis (PD) patients and explored the influencing factors of serum Mg in stage 5 chronic kidney disease (CKD5) patients.

MATERIAL AND METHODS

All 598 patients with CKD5 from three medical centers in South China were recruited into this prospective cohort study from March 1, 2018, to January 31, 2021. Our study recorded the clinical characteristics and laboratory data of the patients.

RESULTS

Hemodialysis patients (0.99 ± 0.19 mmol/L) had a higher mean serum Mg level than PD patients (0.86 ± 0.20 mmol/L; p < 0.01). Regression analysis showed that only corrected calcium (Ca), phosphate (P), Ca/Mg, Ca × P, albumin (Alb), total protein and creatine (Cr) predicted Mg levels in CKD5 patients (p < 0.01). Ca/Mg predicts hypomagnesemia with 78% sensitivity and 85% specificity in CKD5 patients. The AUC value corresponding to Ca/Mg was 0.88.

CONCLUSIONS

This multicenter study in southern China showed that for all CKD5 patients, corrected Ca and Alb had a significant positive effect on serum Mg, while Ca/Mg had a significant negative effect on serum Mg. In 123 HD patients, Ca × P was positively associated with Mg while Ca/Mg and P were negatively associated with Mg. In 398 PD patients, Ca × P, Alb, and total protein were positively associated with Mg while Ca/Mg and P were negatively associated with Mg. In 77 non-dialysis patients, corrected Ca, Cr, and total protein were positively associated with Mg while Ca/Mg was negatively associated with Mg. Furthermore, Ca/Mg might be another useful technique to monitor blood Mg levels in CKD5 patients.

CLINICAL TRIAL REGISTRATION

ChiCTR1800014557.