ESPN 54th Annual Meeting

ESPN 2022


 
Correlation between the metabolic profile of urolithiasis in children with idiopathic hypercalciuria and the composition of the deposit assessed by infrared spectroscopy
MALGORZATA PLACZYNSKA 1 JOANNA MILART 1 KATARZYNA JOBS 1 ARKADIUSZ LUBAS 1

1- MILITARY INSTITUTE OF MEDICINE
 
Introduction:

Urolithiasis is an increasingly common condition. Each patient after stone passage should have stone analysis performed. Every child with a urinary stone should be given a complete metabolic evaluation and the stone analysis is its essential component.

Material and methods:

The aim of the study was to establish the relationship between the metabolic profile of urolithiasis in children and the composition of the excreted stone.The study involved 26 children with urolithiasis associated with idiopathic hypercalciuria (aged 1-17 years) from whom stones were obtained for the analysis. The urine pH and the 24-hour urine excretion of phosphorus and oxalate as well as spot urinalysis including ratio of crystaloids to creatinine from the second voided urine sample of the day were assessed. Urinary stones were analyzed by infrared spectroscopy. The relationship between the metabolic data and the stone type was then analyzed, taking into account two types of minerals: stones with a predominance of calcium oxalate dihydrate (weddellite) and calcium oxalate monohydrate (whewellite).

Results:

The ROC analyzes showed that lower values of each of 4 variables: phosphate and oxalate excretion, magnesium-creatinine ratio, urine pH are characteristic for patients with stones containing > 60% of weddellite.  The most useful in identifying these stones were the product of the excreted phosphate and oxalate, and then the excreted phosphate and oxalate, and the urine pH. In the regression analysis finding a reduced value of each of these 4 variables increased more than sixfold the chance of diagnosing urolithiasis with stone composed of over 60% of weddellite (p=0,019).

Conclusions:

The reduced excretion of phosphates and oxalates in the 24-hour urine sample and the reduced magnesium-creatinine ratio, as well as the reduced urine pH in patients with idiopathic hypercalciuria, more than six times increases the probability of diagnosis of calcium oxalate stones with a predominance of > 60% of weddellite.