Metabolic Constituents of Urinary Stone Composition in Sudanese Children

Objectives: The aim of this study was to show the biological characteristics of pediatric urolithiasis in Sudanese patient’s population and evaluation of some metabolic risk factors.
Materials and Methods: We analyzed prospectively urinary stones from 175 consecutive children (129 males, 46 females), aged 3 months to 16 years. Patients were reviewed in Soba Teaching Hospital, Khartoum state Sudan, during the period October 2005-May 2009. The chemical analysis of stones was carried out by Urinary Calculi Analysis Kit, manufacturer DiaSys Diagnostic system GmbH.
One hundred and thirty blood samples (80 patients, 50 controls) were collected from patients with renal stone to screen some metabolic risk factors, serum calcium, serum phosphate, serum uric acid, and serum creatinine. Fifty samples, of 24 hours urine collection (30 patients, 20 controls) were collected to determine the excretion of urine calcium, phosphate and uric acid.  It was analyzed by auto analyzer Cobas Integra 400 Plus.
Statistical Analysis: Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Statistical significance was determined using chi-square test & Fisher exact test.
Results: The sex ratio was 2.8:1 boys to girls Clinical presentation of this pathology was dominated by flank pain (67%), urinary tract infection (49%) hematuria (27%), and acute renal failure (6.2%). Stones were located in the upper urinary tract in 74.9% of cases. Calcium Oxalate was found more frequently in children stones than infants (P < 0.0001) and was the main component in 55.4% of stones constituents. Cystine stone was more frequent in infant than children (P < 0.011). Uric acid stones were more frequent among boy’s stones than girls’ (8% vs 0.6%) (P<0.05).
Metabolic urolithiasis cases accounted for 6.3% of our patients, and earlier onset of symptoms, were more common in patients with positive family history of urolithiasis, increased frequency multiple and bilateral stones were observed in this group compared with the other etiologic groups. There was increase urinary calcium, uric acid excretion in patients with renal stones (p>0.009, p> 0.013 respectively).
Conclusions: urolithiasis is a serious problem among Sudanese children with early onset of presentation. Proper management of UTI with a careful metabolic assessment of young stone formers is valuable in combating urolithiasis.