Idiopathic urolithiasis in Tunisian children: A report of 134 cases

Abstract

We evaluated the metabolic and the nutritional aspects of 134 urolithiasis children in order to outline the characteristics of idiopathic urolithiasis in children. This prospective study group of 134 children (56 females, 78 males) with renal calculi was evaluated. The age range of the patients was six months to 16 years. A dietary survey was performed on every child. All patients were investigated with respect to stone localization and serum and urine risk factors. Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Hypercalciuria was the most common risk factor detected in this group (28.3%). A decrease of water intake was noted in all age groups, especially in the rural area (549.6 mL/day vs. 1150.6 mL/day), and there was 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) were detected in the ten to 16 years age group (51%) of our study. Calcium oxalate monohydrate represents the principal component of idiopathic stone (58.2%), which is more frequent in children (68%) than in infants (51.7%) (P <0.02). The major etiology of idiopathic urolithiasis highlights the influence of dietary habit in stone formers in our country. The increased occurrence of calcium oxalate stones in school age children confirms the change in the etiology of urolithiasis according to age.

A Comparison between Clinical and Metabolic Features of Renal Calyceal Microlithiasis and Overt Urolithiasis in Different Pediatric Age Groups

“…The changes in dietary habits and consumption of oxalate-rich foods among the pre-school children seem to be an important cause of hyperoxaluria in these children; studies have shown that hyperoxaluria is significantly higher when the children are >1 year and are switched to solid foods [12,14]. The hot climate and higher prevalence of consanguineous marriage are other causes of hyperoxaluria in our region [17,19]. …”

“…This may be one of the reasons for the recent increase in the incidence of urolithiasis in children, due to the important inhibitory effect of citrate on stone formation [23]. It is believed that dietary habits in older children, mainly diets containing high sodium and animal protein with low fruit and vegetables and environmental factors such as soil properties, play a key role in the lower citrate excretion in the urine [14,19,23,24]. …”

“…In our region, drinking water is not recommended for breastfed infants; this, in addition to the hot climate, could cause mild dehydration in these babies, which might be the cause of increased urinary uric acid values [3,17,18,19]. Tubular immaturity that is associated with decreased reabsorption of uric acid is also a main reason of hyperuricosuria in infants [18,19]. …”

Metabolic features and renal outcomes of urolithiasis in children

“…Some studies have reported that the annual incidence of pediatric urolithiasis has increased over the last century in response to the risk factors including dietary changes, metabolic abnormalities, climate change, infection patterns, and genitourinary abnormalities. [4][5][6][7][8][9] In Tunisia, the dietary habit such as an increase in animal protein intake and increased intake of starchy foods and food with high oxalate content influenced the stone formation in children. 4 In the USA, the sex distribution of pediatric urolithiasis varied with age, and there is a possibility of the hormonal effect on the stone formation.…”

“…[4][5][6][7][8][9] In Tunisia, the dietary habit such as an increase in animal protein intake and increased intake of starchy foods and food with high oxalate content influenced the stone formation in children. 4 In the USA, the sex distribution of pediatric urolithiasis varied with age, and there is a possibility of the hormonal effect on the stone formation. 5 In Thailand, the high prevalence of metabolic disorders such as renal tubular acidosis was associated with the high prevalence of renal stone associated with hypocitraturia.…”