[Comparative variations in natriuresis and urinary calcium in patients with hypercalciuric lithiasis treated with...

Because of the close relation between sodium (Na) and calcium (Ca) tubular reabsorption, restriction of sodium intake has been proposed in hypercalciuric stone formers. We simultaneously measured urinary concentrations of both ions in 30 recurrent stone formers (19 male, 11 female, mean age 40,8 +/- 10,2 years) with fasting hypercalciuria, before and after reduction of calciuria using long-term thiazide (TZ) treatment associated with moderate restriction of calcium intake, without concomitant Na restriction. No recurrence of stones was observed in this group with a 12 to 49 month follow-up. UCa strongly correlated with UNa in both conditions. However, UCa significantly decreased with TZ (128 +/- 32 vs 73 +/- 26 mumol/kg/day, p less than 0.001), whereas neither UNaV (190 +/- 60 vs 202 +/- 57 mmol/day) nor diuresis significantly varied. We conclude that calciuria can be lowered without reduction in Na intake in hypercalciuric stone formers controlled by thiazide treatment.