From the Guidelines
Chronic kidney disease (CKD) typically manifests with hypermagnesemia, especially in advanced stages, as the kidneys lose their ability to effectively excrete magnesium, leading to elevated serum magnesium levels. As kidney function declines, approximately 70-80% of serum magnesium is filtered by the glomeruli, with most being reabsorbed in the loop of Henle and distal tubule, and when glomerular filtration rate decreases in CKD, magnesium excretion becomes impaired 1. Hypermagnesemia is particularly common in end-stage renal disease (ESRD) or CKD stages 4-5. However, it's essential to note that hypomagnesemia can occasionally occur in CKD patients due to factors such as medication use (particularly diuretics like loop diuretics), malnutrition, alcoholism, or gastrointestinal losses.
Some key points to consider in the management of CKD patients include:
- The use of commercial KRT solutions enriched with phosphate, potassium, and magnesium can help prevent the onset of hypophosphatemia, hypokalemia, and hypomagnesemia 1.
- The adoption of phosphate-containing KRT solutions has been reported as a safe and effective strategy to prevent CKRT-related hypophosphatemia, limiting the need for exogenous supplementations 1.
- Concerning magnesium, despite the majority of the originally KRT solutions being characterized by a low magnesium concentration to correct the KF-related hypermagnesemia, with the diffusion of regional citrate anticoagulation, the use of dialysis and replacement fluids with increased magnesium concentration may be indicated to prevent KRT-related hypomagnesemia 1.
In terms of morbidity, mortality, and quality of life, it is crucial to monitor and manage magnesium levels in CKD patients to prevent complications such as hypotension, respiratory depression, lethargy, confusion, and cardiac abnormalities. Management typically involves dietary magnesium restriction, avoiding magnesium-containing medications (including antacids and laxatives), and in severe cases, dialysis may be required to remove excess magnesium. Patients with severe hypermagnesemia may experience symptoms including hypotension, respiratory depression, lethargy, confusion, and cardiac abnormalities, highlighting the importance of prompt and effective management 1.
From the Research
CKD and Magnesium Levels
- CKD can manifest with both hypermagnesemia and hypomagnesemia, depending on various factors such as kidney function, dietary intake, and medication use 2, 3, 4, 5, 6.
- HyperMagnesemia can occur in patients with impaired glomerular filtration and magnesium excretion, particularly those taking magnesium-containing drugs such as laxatives and cathartics 2, 4.
- Hypomagnesemia can occur in patients with CKD due to decreased gastrointestinal absorption and kidney reclamation of magnesium, and can be associated with various complications such as hypertension, vascular calcification, and increased risk of cardiovascular disease and mortality 3, 5.
Factors Influencing Magnesium Levels in CKD
- Dietary intake of magnesium is a significant determinant of serum magnesium concentration in patients with CKD, particularly those on hemodialysis 4.
- Medication use, such as magnesium-containing phosphate binders, can also impact magnesium levels in patients with CKD 4.
- Kidney function, as measured by glomerular filtration rate, can also influence magnesium levels, with decreased kidney function leading to increased magnesium levels 3, 6.
Clinical Implications
- HyperMagnesemia has been associated with increased risk of cardiovascular events and all-cause mortality in patients with CKD 6.
- Hypomagnesemia has been associated with various complications, including hypertension, vascular calcification, and increased risk of cardiovascular disease and mortality 3, 5.
- Magnesium supplementation should be used with caution in patients with CKD, particularly those with hypermagnesemia, due to the potential risks associated with excessive magnesium levels 6.