Clinical Characteristics of Hypercalciuric Patients with Urinary Stone

Lee, Sun Ju; Lee, Choong Hyun; Chang, Sung Goo; Kim, Jin Il

Abstract

Hypercalciuria is the most important risk factor in stone formation, occuring in about 50% of patients with calcium containing stone. Also, it is thought that hypercalciuria is a heterogeneous disorder. We studied 408 hypercalciuria patients with urinary stone for the evaluation of clinical characteristics of hypercalciuric over eleven years from 1986 to 1996. Hyperuricosuria was found 26.3% in male and 10.8% in female, respectively. Incidence of hyperuricosuria in hypercalciuric patients with stone was significantly higher than that of patients with urinary stone. The frequency of recurrent stone was 43.1% (100/232) in male, 27.8% (49/176) in female. It was also significantly higher than that of patients with urinary stone, but there was no difference of urinary calcium between recurrence group and single episode group in hypercalciurics. As causes hypercalciuria, hypercalcemia was found in 36 patients, primary hyperparathyroidism in 17, immobilization syndrome in 8, hyperthyroidism in 4 and long term use of steroids in 1, repectively. As a result of oral calcium loading test, absorptive and renal leak type were found 6 patients (14.6%), respectively, resorptive type in 6 (14.6%) and 22 patients (53.7%) were not classified. Based on our experience, we also confirmed that idiopathic hypercalciuria was the heterogeneous sorder. High incidence of hyperuricosuria in urinary stone patients with hypercalciuria might be related with high intake of animal protein. Hypercalciuria was closely related with recurrence of stone but the degree of hypercalciuria was not related with its recurrence. Classification of idiopathic hypercalciuria by oral calcium loading test was available in half the cases.