ABSTRACT
Since 1980s, the clinical and biological characteristics of urolithiasis in Tunisian children have continuously evolved. This retrospective study defines the current status of urolithiasis among children and adolescents in Tunisia. We retrospectively reviewed the records of 310 children and adolescents [age: 3 months - 19 years] between 2003 and 2010, holding urolithiasis. A first-line metabolic, urine and plasma work-up was performed in all patients. Physical and chemical analysis of the stones was performed respectively by stereomicroscopy and infrared spectroscopy. Statistical analysis of the results was performed with SPSS 11.0 software. The Chi-square test was used for comparison of percentages. Our study shows a male predominance of urolithiasis with a sex ratio of 1.5. Stones were located in the upper urinary tract in 70.7% of cases. Calcium oxalate was the predominant constituent in 52.6% of stones. There was an increasing prevalence of calcium oxalate stones according to age in both genders [48.6% in infants vs 68.5% in teenagers [P<0.01]]. Struvite was more frequent in patients aged 2-9 years [P<0.02] and significantly more prevalent in boys than in girls [P<0.001]. Ammonium urate stones were observed in 14.2% and were more frequent in infants. Our results emphasize a high percentage of calcium oxalate stones and a low percentage of struvite stones. The persistence of urate stones reflects the particular eating habits and the infectious risk factors. The patient's age is an important factor that must be taken into account during etiopathogenic work-up
ABSTRACT
BACKGROUND: Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age. METHODS: We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. RESULTS: The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. CONCLUSIONS: The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.