Magnesium and Drugs Commonly Used in Chronic Kidney Disease

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.

Magnesium to prevent kidney disease-associated vascular calcification: crystal clear?

Vascular calcification is a prognostic marker for cardiovascular mortality in chronic kidney disease (CKD) patients. In these patients, magnesium balance is disturbed, mainly due to limited ultrafiltration of this mineral, changes in dietary intake and the use of diuretics. Observational studies in dialysis patients report that a higher blood magnesium concentration is associated with reduced risk to develop vascular calcification. Magnesium prevents osteogenic vascular smooth muscle cell transdifferentiation in in vitro and in vivo models. In addition, recent studies show that magnesium prevents calciprotein particle maturation, which may be the mechanism underlying the anti-calcification properties of magnesium. Magnesium is an essential protective factor in the calcification milieu, which helps to restore the mineral-buffering system that is overwhelmed by phosphate in CKD patients. The recognition that magnesium is a modifier of calciprotein particle maturation and mineralization of the extracellular matrix renders it a promising novel clinical tool to treat vascular calcification in CKD. Consequently, the optimal serum magnesium concentration for patients with CKD may be higher than in the general population.

Medication based machine learning to identify subpopulations of pediatric hemodialysis patients in an electronic health record database

Electronic health records (EHRs) have given rise to large and complex databases of medical information that have the potential to become powerful tools for clinical research. However, differences in coding systems and the detail and accuracy of the information within EHRs can vary across institutions. This makes it challenging to identify subpopulations of patients and limits the widespread use of multi-institutional databases. In this study, we leveraged machine learning to identify patterns in medication usage among hospitalized pediatric patients receiving renal replacement therapy and created a predictive model that successfully differentiated between intermittent (iHD) and continuous renal replacement therapy (CRRT) hemodialysis patients. We trained six machine learning algorithms (logistical regression, Naïve Bayes, k-nearest neighbor, support vector machine, random forest, and gradient boosted trees) using patient records from a multi-center database (n = 533) and prescribed medication ingredients (n = 228) as features to discriminate between the two hemodialysis types. Predictive skill was assessed using a 5-fold cross-validation, and the algorithms showed a range of performance from 0.7 balanced accuracy (logistical regression) to 0.86 (random forest). The two best performing models were further tested using an independent single-center dataset and achieved 84–87% balanced accuracy. This model overcomes issues inherent within large databases and will allow us to utilize and combine historical records, significantly increasing population size and diversity within both iHD and CRRT populations for future clinical studies. Our work demonstrates the utility of using medications alone to accurately differentiate subpopulations of patients in large datasets, allowing codes to be transferred between different coding systems. This framework has the potential to be used to distinguish other subpopulations of patients where discriminatory ICD codes are not available, permitting more detailed insights and new lines of research.

Preparation of Mg/PCL electrospun membranes and preliminary study

Magnesium (Mg) metal and its alloy degradation product magnesium ion (Mg2+) can stimulate the metabolic activity of bone cells, which is beneficial to bone growth and healing. With biodegradable polycaprolactone (PCL) and magnesium particles as raw materials, electrospinning technology is used to prepare electrospun membrane materials doped with magnesium particles. Meanwhile, the scanning electron microscope, X-ray diffraction analysis technology and microcomputer-controlled electronic universal testing machine are adopted to analyze the physical and chemical properties of the material. The biocompatibility of electrospun membranes and their potential to induce osteogenic differentiation of human dental pulp stem cells (hDPSCs) were evaluated by in vitro cell experiments. The results showed that magnesium/PCL electrospun membranes doped with magnesium particles were successfully prepared with electrospinning technology, and the material has a good porous structure. Magnesium/PCL electrospun membranes have good biocompatibility and have the potential to induce osteogenic differentiation of hDPSCs. Among them, the effects of 10% magnesium/PCL electrospun membranes were the most obvious. Clinically, these materials provide new ideas for the restoration of alveolar bone defects and provide an experimental basis for the realization of alveolar bone regeneration.

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.

Prevalence and risk factors of long-term proton pump inhibitors-associated hypomagnesemia: a cross-sectional study in hospitalized patients

Proton pump inhibitors (PPI)-related hypomagnesemia is a potentially life-threatening adverse event first described in 2006. PPIs are widely used in the general population. Information regarding prevalence and risk factors is scarce. We conducted a cross-sectional study in inpatients to evaluate prevalence and associated factors with hypomagnesemia in chronic PPIs users. This is a cross-sectional study of hospitalized adult patients with chronic use of PPIs from January 01, 2012, to December 31, 2018. Chronic use was defined as taking PPIs at least 6 months before hospital admittance. Data were collected from informatized medical records from a University Hospital (Hospital Italiano de Buenos Aires). Hypomagnesemia was defined as a value equal to or less than 1.7 mg/dl. The first hospitalization measurement was retrieved. Thirty-six percent of patients (95% CI 30-43) with chronic PPI use presented hypomagnesemia at admission. Patients with hypomagnesemia presented a higher prevalence of chronic kidney disease (18.6% vs 8%, p < 0.05), more use of oral magnesium supplementation (20.9% vs 8%, p < 0.05), use of corticosteroids (32.6% vs 19.3%, p = 0.06) and calcineurin inhibitors (17.4% vs 6.7%, p < 0.05). Regarding laboratory findings, they presented lower hematocrit (28.7% vs 32.8%, p < 0.05), phosphatemia (3 mg/dl vs 3.4 mg/dl, p < 0.05), natremia (135 mg/dl vs 136 mg/dl, p < 0.05) and albumin levels (2.8 g/dl vs 3.2 g/dl p < 0.05) when compared to those who presented normomagnesemia. Hypocalcemia was more frequent among patients with hypomagnesemia (57% vs 38.7%, p < 0.05). In the multivariate analysis, hyponatremia, decreasing levels of hematocrit (odds ratio, OR 0.93-CI 95% 0.88-0.98) and malignant bone compromise (OR 2.83-CI 95% 1.04-7.7) were associated with hypomagnesemia. Adult patients with long-term use of PPIs have a high prevalence of hypomagnesemia. Increasing age, female sex, concomitant use of drugs that impair tubular function and chronic kidney disease may enhance this phenomenon. Anemia, hyponatremia and malignant bone compromise were associated factors with PPIs-related hypomagnesemia.

Association between serum magnesium and anemia in patients with chronic kidney disease

PURPOSE

An inverse association was shown between serum magnesium levels and anemia in the general population. However, limited information is available about the association between serum magnesium level and anemia in the patient population with chronic kidney disease. We aimed to investigate the relationship between hypomagnesemia and anemia in pre-dialysis patients with chronic kidney disease stage 3-5.

METHODS

This cross-sectional retrospective study included 213 chronic kidney disease patients with an estimated glomerular filtration rate of 60 mL/min and below. Laboratory and demographic data of outpatients were collected in January 2018-January 2019. Patients with a magnesium level below 1.9 mg/dL were accepted as the hypomagnesemia group.

RESULTS

Serum magnesium level of 62 (29.1%) of these patients were below 1.9 mg/dL. Compared with normomagnesemic patients, hypomagnesemic patients had lower mean hemoglobin values (11.3 g/dL vs. 12.7 g/dL, P < 0.001), proton-pump inhibitor usage rates were significantly higher (33.9% vs. 17.2%, P = 0.008) and the median urine protein/creatinine ratio was found to be significantly higher (1017.5 mg/gCr vs. 536 mg/gCr, P = 0.045). In the multivariate analysis, the use of hemoglobin (OR 0.634; 95% CI 0.505-0.795; P < 0.001) and proton-pump inhibitor (OR 2.670; 95% CI 1.113-6.318; P = 0.025) were independent predictors of hypomagnesemia.

CONCLUSIONS

Hypomagnesemia is a common electrolyte disorder in pre-dialysis CKD patients. In this patient group, anemia is independently associated with hypomagnesemia.