Prevention of stone formation and bone loss in absorptive hypercalciuria by combined dietary and pharmacological interventions.
OBJECTIVE
We determined whether dietary restriction of calcium and oxalate, combined with thiazide and potassium citrate treatment, would prevent stone formation and avert bone loss in 18 men and 10 women with type I absorptive hypercalciuria.


METHODS
Patients were treated with thiazide (20) or indapamide (8) and potassium citrate (average dose 35 mEq. daily) for 1 to 11 years (mean 3.7) while maintained on low calcium oxalate diet. Serum and urinary chemistry studies and bone mineral density were measured at baseline and at the end of treatment. New stones formed were quantitated during 3 years before and during treatment.


RESULTS
During treatment urinary calcium significantly decreased (346 +/- 85 to 248 +/- 79 mg. daily, p <0.001) but urinary oxalate did not change. Urinary pH and citrate significantly increased, and urinary saturation of calcium oxalate significantly decreased by 46%. Stone formation rate decreased significantly from 2.94 to 0.05 per year (p <0.001). L2-L4 bone mineral density increased significantly by 5.7% compared to normal peak value, and by 7.1% compared with normal age and gender matched value. Femoral neck bone mineral density also increased significantly.


CONCLUSIONS
Dietary restriction of calcium and oxalate, combined with thiazide and potassium citrate, satisfactorily controlled hypercalciuria, prevented the secondary increase in urinary oxalate, reduced urinary saturation of calcium oxalate, virtually eliminated recurrent stone formation, and increased bone density of the spine and femoral neck. Thus, this dietary pharmacological program controlled stone formation as well as bone loss that often accompany type 1 absorptive hypercalciuria.
Pak
Charles Y
CY
Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390-8885, USA.
Heller
Howard J
HJ
Pearle
Margaret S
MS
Odvina
Clarita V
CV
Poindexter
John R
JR
Peterson
Roy D
RD
D000042:Absorption; D000328:Adult; D001581:Benzothiadiazines; D001862:Bone Resorption / Q000517:prevention & control*; D002118:Calcium / Q000652:urine*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D003131:Combined Modality Therapy; D004032:Diet; D004232:Diuretics; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010070:Oxalates / Q000008:administration & dosage*; D019357:Potassium Citrate / Q000627:therapeutic use*; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use*
D001581:Benzothiadiazines; D002136:Calcium, Dietary; D004232:Diuretics; D010070:Oxalates; D049993:Sodium Chloride Symporter Inhibitors; D019357:Potassium Citrate; D002118:Calcium