Is hypocitraturia associated with phosphaturia--a potential cause of calcium urolithiasis in first-time stone formers.

The serum and 24 hour urinary excretion levels of various lithogenic and inhibitory substances were assessed in 24 male patients with calcium stone and no previous history of urolithiasis and in 19 age-matched controls. Two groups did not differ significantly (P < 0.01) except in the excretions of sodium, citric acid (being higher in normals) and inorganic phosphate (being higher in patients). Fifty percent patients had hyperphosphaturia, 29.2% hypocitraturia, 20.8% hyperoxaluria and 16.7% hypercalciuria. The present data suggests that hypocitraturia in association with phosphaturia might be one of the main risk factors responsible for calcium urolithiasis in this area.