Composition of urinary tract stones formed by children in two populations in the Uyghur region of China

Background: To retrospectively compare the composition of urinary tract stones formed by Uyghur children from the southern (Kashgar) and northern (Urumchi) parts of the Xinjiang region. Methods: The chemical composition of urinary tract calculi formed by 855 Uyghur children from the two regions in Xinjiang (366 Kashgar and 489 Urumchi) was compared retrospectively. Stone composition was determined by infrared spectroscopy. Factors that might have been of relevance for the findings such as age, gender, stone location and geographic region were also considered. Results: Kashgar children were younger than Urumchi children (2.8 +/- 2.7 vs. 4.3 +/- 3.7 years, p < 0.001). Although ammonium urate was the dominant stone component in the whole population, calcium oxalate was most common in children from Urumchi. The mean occurrence of ammonium urate, calcium oxalate and uric acid differed significantly between stones formed by Kashgar and Urumchi children (52.5% vs. 29.2%, 18.9% vs. 29.4%, 12.3% vs. 20.9%; respectively, p < 0.001). Renal stones were less frequently recorded in Kashgar children than in Urumchi children (65.8% vs. 91.6%, p < 0.001). Interestingly, bladder stones were more common in children from Kashgar (28.4% vs. 3.7%; p < 0.001). Conclusion: Uyghur children from the southern part of Xinjiang apparently had a more serious form of stone disease than children from the northern part and the occurrence of stones dominated by ammonium urate stones was extremely high in children from the southern part of the region. Copyright (C) 2018, the Chinese Medical Association. Published by Elsevier Taiwan LLC.