[Urinary magnesium excretion in nephrolithiasis].

Area of Science:

• Nephrology
• Urology
• Biochemistry

Background:

• Nephrolithiasis, or kidney stone disease, affects a significant portion of the population.
• Understanding the metabolic factors contributing to kidney stone formation is essential for effective treatment.
• Urinary excretion patterns of minerals like magnesium and calcium play a role in stone pathogenesis.

Purpose of the Study:

• To investigate magnesium urine excretion and its relationship with calcium urine excretion in patients with nephrolithiasis.
• To assess the impact of calcium loading on magnesium excretion in both healthy individuals and nephrolithiasis patients.
• To evaluate the significance of the magnesium to calcium ratio (MgU/CaU) in determining lithogenic risk.

Main Methods:

• Atomic-absorption spectrophotometry was used to measure urinary magnesium and calcium levels.
• The study included 152 patients diagnosed with nephrolithiasis (unilateral and bilateral).
• Calcium loading tests were performed to observe the response of magnesiumuria.

Main Results:

• Lowered magnesium urine excretion was observed in 14.5% of unilateral and 25.6% of bilateral nephrolithiasis patients.
• Healthy individuals showed a significant positive response in magnesiumuria after calcium loading.
• Nephrolithiasis patients with initially low magnesium excretion exhibited only an insignificant increase in magnesiumuria post-calcium loading.

Conclusions:

• The ratio of magnesium to calcium in urine (MgU/CaU) is a critical indicator for evaluating lithogenic risk.
• The interrelation between calcium and magnesium excretion is of significant clinical importance for managing nephrolithiasis.
• Determining the Ca-Mg interrelation is a mandatory step in the comprehensive evaluation and treatment of nephrolithiasis patients.