struvite and purine

The epidemiology of renal stones has changed all over the world toward a predominance of calcium oxalate stones. However, studies evaluating the influence of age and gender on the distribution of the various types of urinary calculi are scarce. We will present the results of a study based on 205 calculi (from 122 boys and 83 girls) analyzed by infrared spectroscopy between 1993 and 2007. 90% of stones were collected by surgery, whereas only 6% by spontaneous passage. The biological exploration was performed in only 126 cases. Etiology was metabolic in 13.5%. 10.7% of stones were infectious, 13.1% were endemic and 54.9% were idiopathic. 7.8% were secondary to urinary stasis with malformation but no infection. Calcium oxalate (CaOx) was the predominant constituent in 54.7% of stones, followed by calcium phosphate and purines 14.6% in each of the cases. We found an increasing prevalence of calcium oxalate stones with age in both genders (42.9% in infant vs. 59.3% in child) (P < 0.05). Struvite stones were more frequent in infant than children. Purine stones were predominant in 20% of cases, but its prevalence decreases with age. The increase in calcium oxalate stone in school age children and the decrease in struvite and purine stones confirm the change on the etiology of urolithiasis according to age.

Topics: Adolescent; Age Factors; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Purines; Spectrophotometry, Infrared; Struvite; Tunisia

The epidemiologic characteristics are significant to take into account in order to determine the etiology of the paediatric urinary calculi. In this study we studied the composition of stones according to the sex and the age.. Our study focuses on 205 tunisian children aged between three months and 16 years, admitted in our service between 1993-2007. A first urinary metabolic balance was conducted among 126 patients. The physical and chemical stones analysis was performed respectively by a stereomicroscope and infrared spectroscopy. Statistical analysis of the results was made using the software SPSS11.0.. Bladder stone was present in 30.7%. It was more frequent in infants than children over 10 years (p<0.02). The Whewellite was present in 72.7% and predominant in older children stones (59.3% vs 42.9% in infants) (p<0.05). Purines stones were more common among infants. Struvite has been the major compound in only 7.8% of cases where it was more common in infants (p<0.05) male (p<0001).. The higher prevalence of calcium oxalate stones and weaker purin ones in old children suggested the presence of different lithogenous factors of risk according to the age. A modification of the food practices is probably in question.

Topics: Adolescent; Age Factors; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Infant; Magnesium Compounds; Male; Phosphates; Prevalence; Purines; Struvite; Tunisia; Urinary Bladder Calculi; Urolithiasis