Effect of a Phosphate Modified Diet on Phosphate Balance and Phosphate Metabolism in Predialysis Patients Stage 3-4

Study Overview
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Brief Summary
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Patients with chronic kidney disease struggle to eliminate phosphate as the renal function deteriorates, which results in accumulation of phosphate in the body. This has been shown to increase the patients' risk of cardiovascular disease and death. Even with dialysis treatment the patients cannot excrete enough phosphate to reach phosphate balance. The patients are therefore recommended a very restrictive diet when they reach the dialysis stage. It is therefore important to find ways to prevent such accumulation of phosphate in the body as early in the disease process as possible, but without compromising the nutritional status. Because phosphate occurs naturally in many of our foods, such as meat, fish and dairy products, it is difficult to reduce the intake of phosphate, without also reducing the intake of energy and protein. Over the past couple of years there has been an increased focus on the use of phosphate containing additives in the food industry. A reduction in the intake of phosphorus containing additives may reduce the accumulation of phosphate in the body. This can be achieved by decreasing the intake of processed food products. Because it is also very time consuming and inconvenient for the patient to keep these strict diets, the patients have a reasonable claim to know which effects can be achieved by such diets. This will therefore seek to be further explored in the following study. The study is conducted as a randomised crossover trial in predialysis patients stage 3-4.

Official Title
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Effect of a Phosphate Modified Diet on Phosphate Balance and Phosphate Metabolism in Predialysis Patients Stage 3-4

Conditions
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Chronic Kidney Disease

Intervention / Treatment
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* Other: Diet with phosphate containing additives
* Other: Diet without phosphate containing additives


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients > 18 years. Diagnosed with Chronic Kidney Disease stage 3-4 (GFR 15-59 ml / min) p-phosphate between 0.85 mmol / L (2.7 mg / dL) and 1.50 mmol / L (4.7 mg / dl) Read and understand Danish Have received oral and written information about the study Signed informed consent form Exclusion Criteria: Diagnosed hyperphosphatemia Diagnosed hyperparathyroidism Treatment with phosphate binders Dysphagia Diagnosed with decreased absorption capacity in the intestine Co-morbidities in liver, pancreas or lungs Dementia Pregnancy / breastfeeding Embedded within the last 4 weeks Kidney transplant Terminal patients

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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Phosphate modified diet<br> | Other: Diet with phosphate containing additives<br> <br> Other: Diet without phosphate containing additives<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phosphate balance |  | 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| p-phosphate |  | 1 week | 
| p-PTH |  | 1 week | 
| p-Calcium |  | 1 week | 
| FGF23 |  | 1 week | 
| p-25(OH)D |  | 1 week | 
| Calcium-phosphate product |  | 1 week | 
| p-alkaline phosphatase |  | 1 week |