Determination of Urine Saturation with Computer Program Equil 2 As a Method for Estimation of the Risk of Urolithiasis

Abstract

To investigate the risk for the development of urolithiasis in 30 children with urolithiasis, 36 children with isolated hematuria, and 15 healthy control children, 24-h urinary excretion of calcium, sodium, oxalate, citrate, sulfate, phosphate, magnesium, urate, chloride, ammonium, and glycosaminoglycans was determined and urine saturation for calcium oxalate was calculated with the computer program EQUIL 2. Compared with controls, children with urolithiasis had significantly increased calcium excretion, oxalate excretion, and urine saturation, whereas children with isolated hematuria had significantly increased calcium excretion only. The best estimation of the relative risk of urolithiasis can be made after urine saturation, using logistic regression. The percentage of patients correctly classified after urine saturation is 85.41% in comparison with 80.95% and 73.81% when the estimation was done by calcium excretion and oxalate excretion, respectively. Using the breakpoint value of 4.29 for urine saturation, it was possible to separate children with increased risk of urolithiasis development from the group of children with isolated hematuria.

Increased dietary long-chain polyunsaturated fatty acids alter serum fatty acid concentrations and lower risk of urine stone formation in cats

“…Concurrently, urine was analyzed for relative super saturation (RSS) for struvite crystals using the EQUIL 2 program [ 20 – 22 ]. In brief, this computer program calculates a urine supersaturation ratio (unitless) with respect to the common kidney stone components.…”

Age-Specific Excretion of Calcium, Oxalate, Citrate, and Glycosaminoglycans and Their Ratios in Healthy Children and Children with Urolithiasis

“…It is likely that peri-pubertal changes account for the observed differences in the profiles for calcium, citrate and GAG excretion of young and older children Studies analyzing urinary promoter/inhibitor variables such as Ca, Ox, Cit and their ratios in children are uncommon in literature. Since Ca is a strong promoter of urolithiasis with possible masking influences over the other promoters/inhibitors, we assumed that previous researchers' negative results of GAGs excretion in children's urine with urolithiasis might be partly due to the inclusion of participants with prominent metabolic promoters (hypercalciuria included) [16,26]. Previous researchers of Ox, Cit and GAGs interactions frequently opted for Ca exclusion [10,11].…”

“…A wide-mouth plastic bottle encompasses 10 mL of 6 N hydrochloric acid (preservative) was used for Ox, Cit and corresponding creatinine urine collection. The 24-h urine samples without the addition of hydrochloric acid were used for measuring GAGs and corresponding creatinine (cr) in urine [ 26 ]. The Combur 9 test (Boehringer Mannheim, Germany) was used as a nitrite marker as well as urine culture to rule out urinary infection.…”

“…The Combur 9 test (Boehringer Mannheim, Germany) was used as a nitrite marker as well as urine culture to rule out urinary infection. Calcium was measured by the cresolphthalein-complexone method [ 26 ]. Dionex Series 4000i gradient ion chromatography was used for Ox and Cit measurement and carbazole method for GAGs determination.…”

“…Ca, Ox, Cit, and all promoter/inhibitor values were calculated with respect to cr. Such a calculation ensures that the urine is collected correctly and correction of the values to the same indicator [ 26 , 27 ].…”