Decreasing Intakes & Absorption of Phosphorus in Haemodialysis Patients Through Food Choices
- Conditions
- Renal DialysisDietary ModificationHyperphosphatemia
- Interventions
- Other: Modified Low Phosphorus Diet PrescriptionOther: Current Low Phosphorus Diet Prescription
- Registration Number
- NCT03146923
- Lead Sponsor
- University College Cork
- Brief Summary
Based on new evidence renal dietitians in Ireland are revising the diet sheet that is used to teach patients about reducing blood phosphate. Changes that renal dietitians plan to make to the dietary phosphorus prescription
* Inclusion of some nuts and pulses
* More detailed education re phosphate additives
* More accurate protein prescription
* Inclusion of more whole grains
* Encouraging the use of foods with a low phosphorus to protein ratio
The investigators want to test the two diet prescription to find out, which one is better at reducing blood phosphate and which one is more acceptable to patients. The investigators also want to make sure it is safe.
- Detailed Description
Background:
Chronic Kidney Disease (CKD) afflicts one in twenty Irish citizens who are over age 45 and is a significant risk factor for cardiovascular disease, premature death and significantly impacts healthcare utilisation. As kidney function deteriorates, phosphorus, upregulates counter regulatory hormones (immunoreactive Parathyroid Hormone (iPTH) and Fibroblast Growth Factor 23 (FGF23), the elevated levels of which are maladaptive. Collectively these abnormalities and their complications are referred to as Chronic Kidney Disease, Mineral \& Bone Disorder (CKD MBD). Hyperphosphataemia or high blood phosphate levels is associated with increased mortality, in dialysis patients, in the earlier stages of CKD and even in patients with normal renal function. The use of phosphorus restricted diets in combination with oral phosphate binders has become well established in the management of patients with CKD stages 3-5 (including CKD stage 5D).
Experts have called for research into the dietary management of phosphate in the CKD population. The current evidence base is weak and in a recent Cochrane systematic review the authors concluded that there was limited low quality evidence to indicate that dietary interventions may positively affect CKD-MBD.
In recent years there has been increased focus on dietary phosphorus restriction in the management of CKD-MBD and a number of experts have suggested changes in how we manage dietary phosphorus. Several potential strategies have been suggested and in response the Renal Interest Group (RIG) of the Irish Nutrition \& Dietetic Institute (INDI) held a 1 day meeting in Dublin in January 2015 which brought together numerous experts in the field to summarise our current understanding and the recent advances in the field.
Following on from this, RIG set up a working group to translate the new knowledge from the advanced study day and from further literature reviews into a modified low phosphate diet sheet.
Almost all people who have end stage kidney disease (ESKD) and require dialysis to survive, follow a dietary phosphorus restriction, to control high blood phosphate, with the aim of reducing the risk of cardiovascular disease, fractures and death.
Research Hypothesis: The modified low phosphate diet sheet is superior to current treatment in haemodialysis patients
Study Objectives
Primary Objective: To determine if the modified low phosphorus dietary prescription is superior to current management in reducing serum phosphate levels in HD patients
Secondary Objectives To determine if the modified low phosphorus diet is tolerable To determine if the modified low phosphorus diet is safe To determine if the modified low phosphorus diet brings the renal diet closer to healthy eating advice e.g. increased fibre intake.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 74
- >18 years
- Self reported urine output less than 2 cups (400mls) / day
- On maintenance haemodialysis for > 3 months
- Phosphate >1.6mmole/L on average of last 3 available routine monthly blood tests
- Hyperkalemia, defined as a predialysis serum K on routine monthly blood test of >6mmoles/l in the month preceding the trial.
- Parathyroidectomy
- Corrected serum calcium <2.2 or > 2.6mmol/L or local normal units where ranges varied significantly from 2.2-2.6mmoles/l.
- Acute concurrent illness, requiring hospitalisation in the 2 weeks prior to recruitment.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Modified Intervention Arm Modified Low Phosphorus Diet Prescription Patients randomised to the intervention arm will be educated using a modified low phosphorus diet prescription. Standard Care Arm Current Low Phosphorus Diet Prescription Patients randomised to the standard care arm will be re educated using the current low phosphorus diet prescription.
- Primary Outcome Measures
Name Time Method Serum Phosphate 1 month Difference in serum phosphate value at 1 month v baseline, in those randomised to the modified diet compared to the difference in serum phosphate value at 1 month v baseline in those randomised to standard care.
- Secondary Outcome Measures
Name Time Method Palatability and Subject Acceptance (Tolerability) 1 month Palatability and subject acceptance of modified diet as assessed by 5 point Likert Scale
Dietary Intake 1 month Between arm difference in dietary phosphate intake (separating phosphate into high \& low bioavailability).
Between arm difference in dietary fibre intake.Serum Potassium (Safety Endpoints): 1 month Check serum potassium in week 2. Difference in serum potassium value at 1 month v baseline, in those randomised to the modified diet compared to the difference in serum potassium value at 1 month v baseline in those randomised to standard care.
FGF23 (Exploratory Endpoint) 1 month Within subject change in geometric mean FGF-23 measurement at baseline as compared to the end of the 1 month intervention. Because of evidence that subjects with diabetes handle phosphorus differently we will analyse result for FGF 23 separately in patients with and without diabetes (Muras et al., 2013, Yoda et al., 2012).
Serum iPTH 1 month Difference in serum iPTH value at 1 month v baseline, in those randomised to the modified diet compared to the difference in serum iPTH value at 1 month v baseline in those randomised to standard care.
Trial Locations
- Locations (10)
Cavan General Hospital
🇮🇪Cavan, Ireland
Mater Misericordia University Hospital
🇮🇪Dublin, Ireland
Galway University Hospitals
🇮🇪Galway, Ireland
Mayo University Hospital
🇮🇪Mayo, Ireland
Fiona Byrne
🇮🇪Cork, Ireland
Midland Regional Hospital Tullamore
🇮🇪Tullamore, Offaly, Ireland
St. Vincents University Hospital
🇮🇪Dublin, Ireland
Beaumont Hospital
🇮🇪Dublin, Ireland
Tallaght Hospital
🇮🇪Dublin, Ireland
University Hospital Limerick
🇮🇪Limerick, Ireland