Dietary interventions for preventing complications in idiopathic hypercalciuria

Area of Science:

• Nephrology
• Metabolic Disorders
• Nutritional Science

Background:

• Idiopathic hypercalciuria is an inherited metabolic disorder causing excessive urinary calcium excretion.
• It is linked to kidney stones (urolithiasis), bone demineralization (osteopenia, osteoporosis), and in children, hematuria and pain.
• Dietary interventions are explored to manage urinary calcium levels and crystallization.

Purpose of the Study:

• To assess the efficacy, effectiveness, and safety of dietary interventions for preventing complications like urolithiasis and osteopenia in idiopathic hypercalciuria.
• To evaluate the benefits of dietary interventions in reducing urological symptoms in children with this condition.

Main Methods:

• Systematic review of randomized controlled trials (RCTs) and quasi-RCTs.
• Searched the Cochrane Renal Group's Specialised Register.
• Data extracted and analyzed using risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI).

Main Results:

• A normal calcium, low protein, low salt diet (5 years) significantly reduced new kidney stone recurrences, oxaluria, and calcium oxalate supersaturation.
• A low salt, normal calcium diet (3 months) decreased urinary calcium and oxalate excretion.
• Other interventions, including dietary fiber and Phyllanthus niruri, showed no significant benefits; no adverse effects were reported.

Conclusions:

• Long-term adherence to a normal calcium, low protein, low salt diet may decrease kidney stone recurrence and associated urinary markers.
• Short-term low salt, normal calcium diets can reduce calciuria and oxaluria.
• Evidence for other dietary interventions is lacking; further research is needed for complications beyond urolithiasis.