What is Magnesium? Magnesium (Mg) is an essential mineral used in the human body as a cofactor in over 300 biochemical reactions necessary for maintaining homeostasis.

Biological Functions of Magnesium The biological functions of magnesium are extensive and diverse, including:

• Production of nucleic acids
• Involvement in all reactions of adenosine triphosphate (ATP)
• Modulation of any activity influenced by intracellular calcium concentration (such as insulin release and muscle contraction)

Key Role of Magnesium Magnesium plays a key role in the activity of:

• Neuroendocrine systems
• Biological pathways
• Processes related to the pathophysiology of depression For example, all elements of the limbic system, hypothalamus, pituitary, and adrenal cortex are magnesium-dependent.

The Relationship Between Magnesium and Anxiety There is evidence linking magnesium to anxiety, which has led to increased interest in the potential effectiveness of magnesium supplementation for reducing anxiety symptoms. Common pharmacological anxiety treatments (e.g., benzodiazepines) are often associated with multiple negative side effects for many patients.

Therefore, identifying new effective treatments to reduce anxiety symptoms is beneficial. Magnesium has been found to:

• Reduce anxiety
• Alleviate depression
• Reduce pain after heart surgery

Coronary Artery Bypass Surgery (CABG) Coronary artery bypass grafting (CABG) is a procedure typically performed on patients with atherosclerosis in one or more coronary arteries with over 70% blockage or in cases involving the left main coronary artery with 60% blockage. This procedure has been performed for approximately 40 years globally. Compared to other treatments, coronary artery surgery is more effective in:

• Relieving angina pain
• Increasing activity tolerance
• Increasing survival
• Improving quality of life

The development of heart surgery and bypass procedures has led to a decrease in mortality rates, but these treatments have specific side effects. Although heart surgery increases life expectancy and quality of life for patients suffering from cardiovascular and chest diseases, it still has significant negative consequences. Post-surgery complications can have a negative impact on the recovery duration for patients.

Recent Evidence on Coronary Artery Bypass Surgery Recent evidence shows that:

• More than 75% of heart surgery patients do not receive adequate and proper care during their hospital stay and experience significant pain during hospitalization.

• There are various complications after heart surgery, including:

  • Cardiopulmonary complications
  • Neurological disorders
  • Anxiety and depression
  • Sleep disturbances
  • Water and electrolyte imbalances
  • Acid-base changes
  • Metabolic changes
  • Kidney and gastrointestinal disorders

Coronary Artery Bypass Surgery Process Like other surgeries, coronary artery bypass surgery is stressful for the patient, with anxiety and depression being common disorders in this group of patients, affecting social functioning, quality of life, and resumption of daily activities. Depression is often accompanied by anxiety, and anxiety disorders are among the most common mood disorders with a high prevalence of over 15% in the general population.

Sleep Disorders During Coronary Artery Bypass Surgery Most cardiovascular patients report sleep disturbances after the procedure, and there is a strong correlation between sleep disturbances and coronary artery disease. Sleep is a physiological need, and quality sleep is essential for maintaining health. Improving the quality of sleep for patients is crucial for better management during rehabilitation periods.

Researchers’ Views on Coronary Artery Bypass Surgery Researchers state that in many patients undergoing heart surgery, sleep deprivation is often a risk factor for delirium post-surgery. Given the harmful effects of delirium, such as excessive sympathetic activation, infections, cardiac arrhythmias, and increased costs due to prolonged hospital stays, improving the quality of sleep for patients is important. Electrolyte imbalances are another common post-surgery complication that poses significant problems for patients. These imbalances include:

• Hypokalemia
• Hyperkalemia
• Hyponatremia
• Hypocalcemia
• Hypomagnesemia

Hypomagnesemia is common after heart surgery, and magnesium serum levels are significantly altered after the procedure. Studies show that over 70% of patients undergoing coronary artery bypass surgery experience hypomagnesemia.

Various Patterns of Magnesium Deficiency Post-Coronary Artery Bypass Surgery Different patterns of magnesium depletion have been proposed after coronary artery bypass surgery, including:

• Hemodilution due to cardiopulmonary bypass
• Neuroendocrine response to surgical stress
• Increased urinary excretion of magnesium
• Decrease in serum magnesium levels after surgery
• Reduction in intracellular magnesium during and after surgery
• Associated with myocardial hypoxia. Other causes of hypomagnesemia include magnesium-ion complexation with heparin. Diuretics are another factor that can interfere with magnesium reabsorption by inhibiting sodium reabsorption.

Magnesium Supplements Magnesium supplements can improve symptoms related to a variety of diseases likely caused by magnesium deficiency, including:

• Hypomagnesemia
• Constipation
• Arrhythmias
• Heart failure
• Acute asthma attacks
• Diabetes
• Fibromyalgia
• Hypertension
• Migraine headaches
• Muscle cramps
• Fatigue

A systematic review and meta-analysis conducted by researchers suggested oral magnesium supplementation for elderly individuals with insomnia. Given that oral magnesium is inexpensive and widely available, clinical trials support the use of magnesium supplements in doses of less than 1 gram up to three times per day for alleviating insomnia symptoms.

Conclusion In conclusion, based on the results of the current review and studies conducted, it can be inferred that:

Patients undergoing open heart surgery often have a higher prevalence of depression, anxiety, and insomnia due to the presence of multiple risk factors. Furthermore, due to magnesium deficiency, various neurotransmitters, including amino acids, nitric oxide, neuropeptides, and cytokines, are altered. Magnesium supplementation may help in managing these conditions effectively.

“Effectiveness of Magnesium During and After Coronary Artery Bypass Grafting (CABG)”

The effectiveness of magnesium during and after coronary artery bypass grafting (CABG) was measured in terms of postoperative pain and respiratory functions, and compared with two other commonly used pain relief medications: codeine and diclofenac, a non-steroidal anti-inflammatory drug (NSAID). Patients were divided into three groups:

• Group A (50 people): Magnesium, 2 grams per 70 kg, was intravenously administered during surgery and continued for the first 3 days after the surgery.
• Group B (50 people): Codeine, 60 mg per 70 kg, was administered orally 4 times a day for 3 days.
• Group C (50 people): Diclofenac sodium, 75 mg, was given orally twice a day for 3 days.

The results showed that magnesium could be a beneficial adjunctive treatment for pain after coronary artery bypass grafting. In this regard, especially in patients with respiratory issues or NSAID intolerance, magnesium might be a better choice compared to NSAIDs and opioids.

References: Boyle, N.B., Lawton, C. and Dye, L., 2017. The effects of magnesium supplementation on subjective anxiety and stress—a systematic review. Nutrients, 9(5), p.429

Faizi, F., & Sepandi, M. (2022). The Effect of Magnesium Oral Supplementation on Anxiety, Depression, and Sleep Quality in Open Heart Surgery Patients: A Review Study. Iranian Journal of Systematic Review in Medical Sciences, 2(1), 76-84.