Urinary lithiasis and idiopathic hypercalciuria: the importance of dietary intake evaluation

To evaluate food intake of patients with urinary lithiasis and idiopathic hypercalciuria (IH).

Between August 2007 and June 2008, 105 patients with lithiasis were distributed into 2 groups: Group 1 (n = 55)--patients with IH (urinary calcium excretion > 250 mg in women and 300 mg in men with normal serum calcium); Group 2 (n = 50)--normocalciuria (NC) patients. Inclusion criteria were: age over 18, normal renal function (creatinine clearance ≥ 60 mL/min), absent proteinuria and negative urinary culture. Pregnant women, patients with some intestinal pathology, chronic diarrhea or using corticoids were excluded. The protocol of metabolic investigation was based on non-consecutive collection of two 24-hour samples for dosages of: calcium, sodium, uric acid, citrate, oxalate, magnesium and urinary volume. Food intake was evaluated through the quantitative method of Dietary Register of three days.

Urinary excretion of calcium (433.33 ± 141.92 vs. 188.93 ± 53.09), sodium (280.08 ± 100.94 vs. 200.44.93 ± 65.81), uric acid (880.63 ± 281.50 vs. 646.74 ± 182.76) and magnesium (88.78 ± 37.53 vs. 64.34 ± 31.84) was significantly higher in the IH group in comparison to the NC group (p < 0.05). As regards the nutritional composition of food intake of IH and NC groups, there was no statistical significant difference in any nutrient evaluated.

In our study, no difference was observed in the food intake of patients with urinary lithiasis and IH or NC.