A new approach to urinary stone analysis acccording to the combination of the components: experience with 7,949 cases

Kidney Stone Composition in Third-World Areas: What Kashgar Tells Us?

OBJECTIVE

To analyze urinary stone compositions in patients from Kashgar, China.

MATERIALS AND METHODS

We analyzed the components of urinary stones in 732 consecutive patients with urolithiasis admitted to the First and Second People's Hospital of Kashgar Prefecture, Xinjiang, from July 2014 to November 2016. The patients were divided into two groups by ages: group A, 0 to 18 years and group B, >18 years old. The distributions of various stone compositions were analyzed and correlated with the gender and age.

RESULTS

The mean age of group A was 3.90 ± 4.09 years and that of group B was 39.88 ± 16.40 years. The overall gender ratio (male:female) was 2.27:1. Ammonium acid urate (AAU) stone was the most frequent stone, male 35.83% and female 33.48%. Female patients were significantly more common than male patients in calcium apatite stone (p = 0.004). Of all 732 cases, patients younger than 18 years were more than patients older than 18 years (58.47% vs 41.53%). The majority of the patients (77.87%) had the stone located in the upper urinary tract. Two peak ages for both genders were noted in 1 to 3 years and 19 to 40 years group of the patients. In group of 1 to 3 years patients, male were more than female (37.60% vs 24.55%, p = 0.001), whereas in the group of 10 to 18 years patients, female were more than male (10.71% vs 4.13%). AAU was the predominant stone component in group <1 year (70. 5%, p < 0.01, as compared with other groups.). Uric acid stone was more prevalent in group >60 years (66.8%, p < 0.01) than in other groups. Patients in 1 to 3 years were in the peak age group of AAU stones in both the upper and lower urinary tract.

CONCLUSION

Most of the patients with urolithiasis diagnosed and treated in Kashgar are <18 years old, especially younger than 3 years old. The most frequent stone component in this area was AAU. More than 50% patients <18 years old had AAU stone. The mechanisms that could trigger the high prevalence of AAU stone in patients <18 years old are worth further investigation.

[Changes in kidney stones type according to sex and age in Tunisian patients]

BACKGROUND

Studies that evaluate the effect of age and gender on the stone composition are scarce. The aim of this study is to highlight the modification of epidemiological characteristics of this pathology according to patients' sex and age.

PATIENTS AND METHODS

We studied 1269 urolithiasic patients ranging from 6 months to 92 years old and known as having urinary stones (752 males and 517 females). Stone analysis was performed respectively using a stereomicroscope and infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each.

RESULTS

The annual average incidence of new stone formation was 30.25 per 100,000 inhabitants. In 1041 patients (81%), calculi were located in the upper urinary tract. Children and old man were more affected by bladder stone. Calcium oxalate monohydrate remains the most frequent stone component even if its frequency fell according to age (63.2% in teenagers and 40.6% in elderly [p<0.05]) in favour of the increase of uric acid stones (3,5% in teenagers and 41.5% in elderly [p<0.05]). Struvite stones were rare (3.5%) and more frequent in children.

CONCLUSION

The analysis of these data shows that urinary stones in Tunisia are tending to evolve in the same direction as in industrialized countries.