The significance of citrate excretion and calcium/citrate quotients in urine in patients with calcium calculi

In 111 patient suffering from calcium oxalate lithiasis more than 168 citrate and calcium analyses have been performed in 24 hour urine. In 69 patients with a single stone episode no significant difference of citrate concentration was found in comparison with 63 healthy volunteers. However, in 42 recurrent stone formers was the citrate concentration significantly diminished (p less than 0.005). The calcium/citrate ratio was in recurrent stone formers markedly higher (5.19 +/- 8.6) than in patients with a single stone episode (3.34 +/- 4.9). However, because great deviation of citrate values the calcium/citrate ratio may not be suitable for evaluation of stone formation risk.