Bone disease in medullary sponge kidney and effect of potassium citrate treatment.

Abstract

BACKGROUND AND OBJECTIVES:

In medullary sponge kidney (MSK)-a common malformative renal condition in patients with calcium nephrolithiasis-hypercalciuria, incomplete distal renal tubular acidosis, and hypocitraturia are common. Clinical conditions with concomitant hypercalciuria and/or incomplete distal renal tubular acidosis are almost invariably associated with bone disease, making osteopathy highly likely in MSK, too. Patients with MSK have never been investigated for osteopathy; neither has the potential effect of potassium citrate administration (CA) on their urinary metabolic risk factors and on bone mineralization.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:

These issues were retrospectively analyzed in 75 patients with MSK and primary stone risk factor (PSRF; hypercalciuria, hypocitraturia, hyperuricosuria, and/or hyperoxaluria) on an outpatient basis; 65 received CA (2.9 +/- 0.8 g/d), whereas 10 received only general "stone clinic" suggestions. The 24-h urinary excretion of calcium, phosphate, oxalate, uric acid, and citrate; morning urine pH; serum biochemistry; and bone mineral density were investigated at baseline and at the end of follow-up (78 +/- 13 and 72 +/- 15 mo in groups A and B, respectively).

RESULTS:

CA led to a significant rise in urinary pH and citrate and decreased urinary calcium and phosphate (all P < 0.001). Patients with MSK and PSRF had reduced bone density. Bone density improved significantly in the group that was treated with oral CA.

CONCLUSIONS:

Bone disease is very frequent in patients with MSK and concomitant PSRF. Long-term CA improves bone density. The concurrent effects of treatment on PSRF suggest that the subtle acidosis plays a pivotal role in bone disease and hypercalciuria in patients with MSK.

• Authors: Antonia Fabris, Patrizia Bernich, Cataldo Abaterusso, Nicola Marchionna, Chiara Canciani, Antonio Nouvenne, Mauro Zamboni, Antonio Lupo, Giovanni Gambaro
• Journal: Clinical journal of the American Society of Nephrology : CJASN (Clin J Am Soc Nephrol) Vol. 4 Issue 12 Pg. 1974-9 (Dec 2009) ISSN: 1555-905X [Electronic] United States
• PMID: 19808216 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Diuretics
• Phosphates
• Potassium Citrate

Topics

• Absorptiometry, Photon
• Acidosis, Renal Tubular (drug therapy, etiology)
• Adolescent
• Adult
• Bone Density (drug effects)
• Bone Diseases (complications, diagnostic imaging, prevention & control)
• Diuretics (administration & dosage)
• Female
• Follow-Up Studies
• Humans
• Hydrogen-Ion Concentration (drug effects)
• Hypercalciuria (drug therapy, etiology)
• Male
• Medullary Sponge Kidney (complications, drug therapy)
• Nephrolithiasis (complications, drug therapy)
• Phosphates (urine)
• Potassium Citrate (administration & dosage)
• Retrospective Studies
• Young Adult