[The significance of hypercalciuria in idiopathic calcium urolithiasis (author's transl)].

THE SIGNIFICANCE OF HYPERCALCIURIA IN IDIOPATHIC CALCIUM UROLITHIASIS Kazuo Matsushita, Masamichi Hayakawa, Toshio Fujioka and Kunio Odajima National Defense Medical College, Saitama, Japan A high percentage of recurrent rate is observed in patients with idiopathic calcium urolithiasis. We selected 86 calcium stone formers with normal serum calcium level and normal urinary tracts. They live in the outer area of Tokyo, are commuters and live on standard foodstuffs. In those patients we tried to find out the frequency of hypercalciuria and its type by performing an oral calcium load test. In addition, we studied the effects of hypercalciuria on recurrence of calcium stone diseases. Hypercalciuria in which 24-hour urinary calcium excretion surpassed 250 mg was observed in 35 of the 86 subjects or 40. 7%. In the other 51 non-hypercalciuric stone formers, daily calcium excretion averaged 154.1+55.0mg. Recurrent and/or multiple stones developed in 10 of the 35 hypercalciuric (29%) and 16 of the 51 normocalciuric patients (31%). The oral calcium load test suggested the etiology of hypercalciuria. Recurrent and/or multiple stones were more frequently formed in possible renal or absorptive hypercalciuric subjects than in those with idiopathic hypercalciuria (3.5:1).