Pathophysiological studies in hypercalciuric and normocalciuric stone formers

This study has been carried out in order to investigate the effects of a standard oral calcium load in 18 hypercalciuric and 18 normocalciuric recurrent stone formers. Following oral loading there was not a significant difference in the two groups studied, as far as serum calcium increment was concerned; however, urinary calcium excretion was significantly greater in hypercalciuric stone formers. The results obtained, although they do not exclude the presence of intestinal calcium hyperabsorption, seem to demonstrate the existence of a diminution of renal tubular calcium reabsorption in patients with idiopathic hypercalciuria