the Regulation of Phosphorus Homeostasis by Dietary Phosphorus Intake in Normal Men

Study Overview
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Brief Summary
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The investigators have conducted the study about the effects of normal diet and low-phosphorus diet on phosphorus homeostasis in healthy subjects, now this study is designed to explore further about the effect of high-phosphorus diet on phosphorus homeostasis.

Detailed Description
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Serum phosphate concentrations are not only associated with cardiovascular and all-cause mortality in chronic kidney disease (CKD) patients, but also associated with the mortality in community population. Thus, maintaining normal serum phosphate and reducing postprandial fluctuation of serum phosphate are essential for healthy people. The investigators have conducted a study about the effects of normal diet (phosphorus 1500mg) and low-phosphorus diet (phosphorus 500mg) on phosphorus homeostasis in healthy men. The results showed low-phosphorus diet could significantly reduce serum phosphorus and urine phosphorus level compared to normal diet. However, the levels of serum FGF23 and a-klotho were not different between these two groups.Thus, the investigators want to further explore the effects of high-phosphorus diet (phosphorus 2300mg)on phosphorus homeostasis in healthy men. Therefore, the investigators plan to conduct a crossover clinical study to evaluate the phosphorus homeostasis modulated by native normal diet, restricted phosphorus diet, high phosphorus diet and then to explore the underlying mechanisms.

Official Title
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the Regulation of Phosphorus Homeostasis by Dietary Phosphorus Intake in Normal Men

Conditions
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Healthy

Intervention / Treatment
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* Other: normal diet
* Other: low-phosphorus diet
* Other: high-phosphorus diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men aged 18-45 years Healthy volunteers: no history of chronic diseases; no active symptoms or physical signs; negative results of electrocardiogram and chest X-ray; biochemical indicators of regular medical examination are within 95%-105% of normal range. Willingness to sign the consent form approved by an Institutional Review Board and comply with the study protocol. Body mass index ranged within 18.5-24 kg/m2. Exclusion Criteria: Current history of drug or alcohol abuse as assessed by the principal Investigator. Subject has blood donations or blood loss more than 300ml within three months Allergic to more than two foods or drugs. Subject has psycho-disability or body disability. Subject has a condition that in the judgment of the Principal Investigator could potentially pose a health risk to the patient while involved in the study. Subject has participated in the other clinical trials at the same time.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

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
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Normal Phosphorus Diet<br>Diet containing 1500mg of phosphorus per day | Other: normal diet<br>* Diet containing 1500mg of phosphorus<br>|
| Experimental: Low-phosphorus Diet<br>Diet containing 500mg of phosphorus per day | Other: low-phosphorus diet<br>* Diet containing 500mg of phosphorus<br>|
| Experimental: High-phosphorus Die<br>Diet containing 2300mg of phosphorus per day | Other: high-phosphorus diet<br>* Diet containing 2300mg of phosphorus<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circadian rhythm of serum phosphorus concentration |  | 24 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circadian rhythm of urine phosphorus concentration |  | 24 hour | 
| Circadian rhythm of plasma fibroblast growth factor 23 (FGF23) |  | 24 hour | 
| Circadian rhythm of parathyroid hormone (PTH) |  | 24 hour | 
| Circadian rhythm of 1, 25-dihydroxyvitamin D (1,25(OH)2D3) |  | 24 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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phosphorus,diet, phosphorus, healthy subject