Comparison of 24-hour Collecting Urine Prior and After Stone Removal

Study Overview
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Brief Summary
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The metabolic evaluation is crucial for determining possible underlying diseases causing stone growth and to consider the lifestyle changes or medical prophylaxis needed to prevent or at least reduce stone recurrence. 24-hour urine collection is the main part of the metabolic evaluation. The time point is suggested between 3 weeks and 3 month after stone removal, but so far there are no studies comparing 24-hour urine prior and after stone removal. In this study, investigators would like to analyze parameters in the 24-hour urine prior and after complete stone removal to see whether metabolic status can be evaluated no matter stone free or not.

Detailed Description
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Background As the metabolic evaluation is an essential part of diagnostic and recurrence prevention of urolithiasis, the current EAU Guidelines, as well as the German S2k guidelines therefore suggest 24-hour urine collection, done twice. This evaluation is crucial for determining possible underlying diseases causing stone growth and to consider the lifestyle changes or medical prophylaxis needed to prevent or at least reduce stone recurrence. The time point is suggested between 3 weeks and 3 month after stone removal, but so far there are no studies comparing 24-hour urine prior and after stone removal. This could simplify the diagnostic and make this essential information available for more patients suffering from urolithiasis. Hypothesis Null hypothesis: The analyzed parameters in the 24-hour urine prior and after complete stone removal differ from each other Alternative hypothesis: The analyzed parameters in the 24-hour urine prior and after complete stone removal do not differ from each other Primary endpoint: The difference of the analyzed parameters prior and after complete stone removal Parameters to be collected 24h urine composition prior and after stone removal: pH value, spec. weight, creatinine, calcium, oxalate, uric acid, citrate, magnesium, phosphate, ammonium, cysteine, sodium, potassium. Secondary: Age, sex, body mass index, stone composition analyzed by infrared spectroscopy, urine culture, comorbidities (diabetes mellitus, hypertension, …), degree of hydronephrosis, serum electrolytes, blood urea nitrogen, serum creatinine, first manifestation or recurrent disease Methods After assessing inclusion and exclusion criteria, all eligible patients administered for active stone removal are included in this study. Prior to surgery, a 24-hour urine collection need to be performed (not longer than 2 month). Post-operatively stone free status is assessed by NCCT, in ureterolithiasis only if stone free status is uncertain. 4 weeks after proven stone free status the post surgical 24h urine collection is performed. If a ureter stent was placed, the 24-hour urine collection is performed 4 weeks after stent removal. All 24-hour collection are performed as outpatients. Patients will be asked to drink and eat normally when they do their urine collection. Urinary volume is measured as a marker of liquid consumption, sodium as a marker of salt intake. Sample size As no available data to show the difference of urine composition prior or after surgery, the study will enroll 100 participants first to get preliminary data. Then the final sample size will be determined by the preliminary data. Statistical Analysis： Comparisons of the urine compositions before and after stone removal will be performed using the Student's t-test for continuous variables and chi-squared for categorical variables.

Official Title
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Metabolic Evaluation of Urolithiasis: Comparison of 24-hour Collecting Urine Prior and After Stone Removal - a Prospective Study

Conditions
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Urolithiasis, Urinary Stone

Intervention / Treatment
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* Other: 24-h urine collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients 18 years or older Urolithiasis (Nephrolithiasis, Ureterolithiasis) Exclusion Criteria: Patients under 18 years Urinary tract infection (positive urine culture prior to surgery) Incomplete 24h urine collection Pregnancy Residual stones after surgery

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experiment group<br>All eligible patients administered for active stone removal. | Other: 24-h urine collection<br>* Collecting 24-h urine prior and after stone removal surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Urine pH Change | pH values will be determined with a glass electrode in a calibrated pH meter | Change from baseline urine pH at 4 weeks after proven stone free status | 
| 24-h Urine oxalate excretion change | Urine oxalate will be measured using ion exchange chromatography | Change from baseline 24-h urine oxalate excretion at 4 weeks after proven stone free status | 
| 24-h Urine citrate excretion change | Urine citrate will be measured using ion exchange chromatography | Change from baseline 24-h urine citrate excretion at 4 weeks after proven stone free status | 
| 24-h Urine calcium excretion change | Urine calcium will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine calcium excretion at 4 weeks after proven stone free status | 
| 24-h Urine phosphate excretion change | Urine phosphate will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine phosphate excretion at 4 weeks after proven stone free status | 
| 24-h Urine sodium excretion change | Urine sodium will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine sodium excretion at 4 weeks after proven stone free status | 
| 24-h Urine potassium excretion change | Urine potassium will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine potassium excretion at 4 weeks after proven stone free status | 
| 24-h Urine chloride excretion change | Urine chloride will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine chloride excretion at 4 weeks after proven stone free status | 
| 24-h Urine creatinine excretion change | Urine creatinine will be measured by Unicel DxC 600 synchronic biochemical detecting system. | Change from baseline 24-h urine creatinine excretion at 4 weeks after proven stone free status | 
| 24-h Urine uric acid excretion change | Urine uric acid will be measured using Beckman coulter AU680 automatic biochemistry analyzer. | Change from baseline 24-h urine uric acid excretion at 4 weeks after proven stone free status | 
| 24-h Urine magnesium excretion change | Urine magnesium will be measured using Beckman coulter AU680 automatic biochemistry analyzer. | Change from baseline 24-h urine magnesium excretion at 4 weeks after proven stone free status | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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urolithiasis, 24-h urine composition