Investigation of Hypophosphataemia Following Intravenous Iron

Study Overview
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Brief Summary
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Anaemia (low haemoglobin levels) can develop in a number of conditions, including chronic kidney disease (CKD) and intestinal conditions (e.g. inflammatory bowel disease, intestinal failure). Intravenous iron can be given to patients with these conditions to help correct their aneaemia. However, intravenous iron has been associated with the development of low phosphate levels - hypophophosphataemia. The aim of this study is to determine potential causes of hypophosphataemia following administration of intravenous iron.

Detailed Description
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Low levels of iron can lead to anaemia, known as iron deficiency anaemia, which can be debilitating due to symptoms such as shortness of breath, fatigue, and dizziness. Iron deficiency anaemia can be treated by giving iron supplementation. Iron supplements can be taken orally or can be given intravenously (through the veins). Giving iron intravenously has advantages over iron supplements taken orally, which can cause side effects such as stomach pain and cramping. However, giving iron intravenously has been associated with the development of low levels of phosphate in the blood. This is known as hypophosphataemia. Phosphate is an important salt in the body and has a number of important functions. Very low levels of phosphate can cause muscle pain, disorientation, seizures and heart problems. It is unclear why giving iron intravenously can cause hypophosphataemia. This project aims to investigate the potential causes of hypophosphataemia in patients who receive intravenous iron as treatment for anaemia associated with their condition. Patients with chronic kidney disease (CKD) and intestinal failure will be recruited to the study, since people with CKD may handle iron differently than those with healthy kidneys. Samples will be taken at two time points: prior to giving the intravenous iron and at the patient's next appointment. Healthy volunteers will also be recruited to the study to allow comparison between the groups receiving iron and those who do not receive iron. Samples will be analysed to determine potential causes of hypophosphataemia. Results from before and after iron is given will be compared to determine if any of the participants developed hypophosphataemia and if any other test are affected which may explain why this has developed.

Official Title
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Investigation of the Mechanisms for the Development of Hypophosphataemia Following Administration of Intravenous Iron in Patients With Severe Anaemia

Conditions
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Anemia, Hypophosphatemia, Chronic Kidney Diseases, Intestinal Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For Patients aged 18 years or older previously diagnosed with intestinal failure or advanced CKD have anaemia requiring administration of intravenous iron be able to adequately speak and understand English Have capacity to give written informed consent For Healthy Volunteers aged 18 years or more be able to adequately speak and understand English have capacity to give written informed consent Exclusion Criteria: For patients have dialysis-dependent CKD participation in any other study which will affect results of the current study For Healthy Volunteers have CKD (eGFR <60 mls/min/1.73^2) history of any form of metabolic bone disease Participation in any other study which will affect the results of the current study

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Chronic Kidney Disease<br>This group will consist of 10 patients who have previously been diagnosed with chronic kidney disease and are receiving intravenous iron due to anaemia. | |
| Intestinal failure<br>This group will consist of 10 patients who have previously been diagnosed with intestinal conditions and are receiving intravenous iron due to anaemia. | |
| Healthy Volunteers<br>This group will consist of 20 healthy volunteers. This group will act as a comparator for the CKD and intestinal failure groups. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FGF23 levels before and after intravenous iron | Measurement of FGF23 levels in patients with CKD before and after intravenous iron administration | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FGF23 levels in patients with CKD and healthy volunteers | Comparison of measured FGF23 levels in patients with CKD and healthy volunteers | 1 week | 
| Characterisation of pre-analytical factors affecting FGF23 levels | To examine the effect of delayed separation and fasting vs non-fasting on FGF23 levels | 1 week |