[Magnesium hydroxide in idiopathic calcium nephrolithiasis]

Area of Science:

• Nephrology
• Urology
• Mineral Metabolism

Background:

• The in vitro protective effect of magnesium against calcium oxalate crystallization is established.
• The clinical significance of magnesium in preventing calcium nephrolithiasis remains under investigation.
• This study aimed to assess the clinical and metabolic impact of magnesium hydroxide in calcium stone formers.

Purpose of the Study:

• To evaluate the clinical and metabolic effects of magnesium hydroxide therapy in patients with calcium nephrolithiasis and low urinary magnesium excretion.
• To determine the impact of magnesium supplementation on urinary stone risk factors and stone recurrence rates.

Main Methods:

• Nine patients with low urinary magnesium excretion (56 +/- 12 mg/day) received magnesium hydroxide (500 mg/day).
• Clinical and metabolic parameters were monitored at 3, 12, and 18 months.
• Key urinary markers assessed included magnesium, oxalate, and calcium relative to creatinine.

Main Results:

• Magnesium hydroxide therapy led to a significant decrease in urinary oxalate excretion (uOx/uCreat).
• The stone recurrence rate decreased substantially from 0.75 to 0.11 stones/year/patient.
• Increased urinary magnesium (Mg/uCreat) and a non-significant increase in urinary calcium (uCa/uCreat) were observed.

Conclusions:

• Magnesium hydroxide therapy demonstrated encouraging results in patients with calcium nephrolithiasis and low urinary magnesium.
• The reduction in urinary oxalate, potentially due to decreased intestinal absorption, is a significant finding.
• Longer-term studies are necessary to confirm the sustained efficacy and safety of this treatment.