Nutritional aspects of idiopathic nephrolithiasis in Tunisian children

We evaluated the metabolic and the nutritional aspects of 134 urolithiasic children, in order to outline the risk factors that contribute to idiopathic stone formation in children.

In this prospective study 134 children (56 females, 78 males) with renal calculi were evaluated. The age of the patients ranged 6 months to 16 years. A dietary survey was performed on every child. All patients were investigated with respect to stone localization, serum and urine risk factors. Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Statistical significance was determined using chi-square test.

Hypercalciuria was the commonest risk factor detected in this group (28.3%). A decrease of water intake was noted in all age group specially in the rural area (549.6 vs 1150.6 ml/day), and an increase in animal protein intake in 17 cases (mean 1.9 g/kg). In addition, increased intake of starchy foods and food with high oxalate content (sorgum) was observed in our 10-16 years group (51%). Calcium oxalate monohydrate represents the principal component of idiopathic stone (58.2%), which is more frequent in children (68%) than infants (51.7%) (P < 0.02).

The high frequency of idiopathic urolithiasis highlights the influence of dietary habit in stone formers in our country. The increase in calcium oxalate stones in school-age children confirms the change in the etiology of urolithiasis according to age.