Study of the Effects of the Consumption of Different Products Cocoa Derivatives at the Risk of Crystallization of Uric Acid in Urine of Volunteers.

Study Overview
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Brief Summary
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The present study aims to assess the effectiveness of theobromine, -product present in high proportion in the cacao-, to prevent the development of uric acid kidney stones.

Detailed Description
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Renal lithiasis is a pathology that affects a high percentage of the population, and although it has been known for a long time, advances carried out in the treatment are limited to the surgical aspects, while the causes responsible for the formation of kidney calculus are not corrected, which leads to a high recurrence. The healing of renal lithiasis inevitably goes through the elimination of the alterations related to the genesis of kidney calculus. It the case of uric acid lithiasis the most important are having urinary pH less than 5.5 and an elevated uricosuria, which can be corrected relatively easy by undergoing changes in dietary habits, and with pharmacological treatment with citrate -which produces and increase in pH- or with inhibitors of the xantino-oxidase as allopurinol. However, among the prophylactic treatments available for ural acid lithiasis, so far it does not exist one for urinary acid crystallization inhibition. Recently, the effects of theobromine as an inhibitor of the crystallization of uric acid have been described, but only in vitro. The present study aims to assess the effectiveness of theobromine, -product present in high proportion in the cacao-, to prevent the development of uric acid kidney stones. The study is a unicentric, low intervention, non-randomized, prospective study to assess the effects of the consumption of different cocoa derivate products, in the risk of crystallization of uric acid in the urine. Participants in the study are healthy volunteers and will it will be carried out with 20 individuals who will be recruited in the Research Laboratory in Renal Lithiasis of the Baleares Isles University. Patients will take a urine test previously to undergo 4 dietary interventions, with their subsequent urine measurements. Patients will choose one diet to follow for 1 day, and will be provided with the corresponding cocoa derivate for the diet (soluble cocoa, black chocolate, chocolate with milk). The day after the diet they will take a fast-picking of urine accumulated during the night of which they followed the controlled diet (12 h nocturne sample), then follow a 6 day washout period, and select another diet to follow and repeat until they have gone through the 4 diets and measurements.

Official Title
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Study of the Effects of the Consumption of Different Products Cocoa Derivatives at the Risk of Crystallization of Uric Acid in Urine of Volunteers.

Conditions
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Lithiasis, Urinary

Intervention / Treatment
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* Dietary Supplement: Intervention 0
* Dietary Supplement: Intervention 1
* Dietary Supplement: Intervention 2
* Dietary Supplement: Intervention 3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Compliance in participating and collaborating in the study Exclusion Criteria: Cocoa / chocolate allergy or theobromine Pregnancy, nursing period (women) pharmacological treatment chronic diseases (diabetes, kidney failure, heart failure, hyperuricemia, ...)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study group<br>All patients will follow four different dietary interventions (with or without cacao) for 1 day prior to the taking of a urine sample. After the sample is taken the patient will follow a washout period of 6 days before following a different diet and this process will be repeated for each patient until they have followed the four diets. . | Dietary Supplement: Intervention 0<br>* Without nutritional intervention, it will consist of normal food intake without food derived from cocoa or coffee for a period of 1 day in the group of 20 patients during meals. ( That day the patient can not consume cocoa derivates nor coffe or coffe derivates).<br>* Other names: Study group;Dietary Supplement: Intervention 1<br>* The nutritional intervention will consist of the intake of 40 g daily a base of food derived from cocoa that will be provided to the paient (Food based on soluble cocoa) during one 1 day period in the group of 20 patients during meals. That day the patient can not consume cocoa derivates nor coffe or coffe derivates exept the one provided.<br>* Other names: Study group;Dietary Supplement: Intervention 2<br>* The nutritional intervention will consist of the intake of 40 g daily a base of food derived from cacao (Food based on black chocolate) during a period of 1 day in the group of 20 patients during meals. That day the patient can not consume cocoa derivates nor coffe or coffe derivates exept the one provided.<br>* Other names: Study Group;Dietary Supplement: Intervention 3<br>* The nutritional intervention will consist of the intake of 40 g daily a base of food derived from cocoa (Food based on chocolate with milk) for a period of 1 day in the group of 20 patients during meals. That day the patient can not consume cocoa derivates nor coffe or coffe derivates exept the one provided.<br>* Other names: Study group;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ability to inhibit the crystallization of uric acid in urine collected. | Ability to inhibit the crystallization of uric acid in urine collected. | 12 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of theobromine in urine. | Concentration of theobromine in urine. | 12 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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lithiasis, uric acid, crystallization