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Vitamin D Supplementation in CKD - Vascular Function, Structure and Immune Regulation

Not Applicable
Completed
Conditions
Atherosclerosis
Chronic Kidney Disease
Interventions
Dietary Supplement: Vitamin D (cholecalciferol)
Registration Number
NCT04380467
Lead Sponsor
St George's, University of London
Brief Summary

A pilot study to assess feasibility of methods of an observer-blinded randomised controlled trial of the effect of vitamin D supplementation in Chronic Kidney Disease and low vitamin D levels on markers of vascular function (Flow Mediated Dilatation of Brachial Artery), vascular structure (Carotid Intima Media Thickness) and Immune Regulation (frequencies of CD4+CD28null T lymphocytes ad Regulatory T lymphocytes).

Detailed Description

The study is a single (observer) blinded feasibility pilot randomised study. Study subjects will be recruited from clinics run by St George's Hospital Renal Department and randomised to treatment arm or no treatment arm.

In treatment arm, six doses of vitamin D tablets (cholecalciferol 100,000 IU, five capsules total) will be administered on weeks 0, 4, 8, 12, 16 and 20. In the no-treatment arm the participants receive no cholecalciferol. Participants will have serum calcium levels measured at week 12.

All participants will undergo estimation of endothelial function, carotid intima-media thickness, CD4+CD28null and regulatory T cell frequency in week 0 and week 26. The observer will be blinded to whether the patient is in the treatment or no-treatment arm whilst the following tests are performed:

1. Measurement of Brachial Artery Flow Mediated Dilatation

2. Measurement of Carotid Intima Media Thickness

3. Quantification of CD4+CD28null and regulatory T cell frequency

The pilot study will assess feasibility of the study methods.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
36
Inclusion Criteria
  1. Age 18-80 years
  2. Calcium < 2.58mmol/l
  3. On an ACE inhibitor/ARB
  4. Vitamin D <75nmol/l
  5. eGFR 15- 60ml/min/1.73m2 and stable
  6. Informed consent to participate
Exclusion Criteria
  1. Patients already on Vitamin D or calcium supplementation
  2. Patients with known malignancies
  3. Patients with autoimmune conditions
  4. Patients with heart failure (ejection fraction <40%, Plasma NT pro-BNP>500pg/ml)
  5. Patients with active infection
  6. Rapidly deteriorating renal function
  7. Recent Acute coronary syndrome or cerebro-vascular event (within the last 6 months)
  8. Uncontrolled hypertension (BP>160 systolic)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Vitamin D GroupVitamin D (cholecalciferol)Six doses of cholecalciferol 100,000units (5x aviticol 20,000units capsules) administered monthly over 20 weeks.
Primary Outcome Measures
NameTimeMethod
Retention rate6 months

Percentage of patients recruited who completed the follow up investigations

Recruitment rate3 months

Percentage of patients recruited from those eligible for the study.

Randomisation procedure6 months

Comparison of baseline indices of two patient groups

Maintenance of single (observer) blinding6 months

Incidences of unblinding of study investigator

Adherence to vitamin D supplementation6 months

Subjective adherence as assessed by Participant Experience Survey and biochemical correlation by comparison of follow up vitamin D levels

Acceptability to patients of randomisation procedures6 months

Acceptability as assessed by quantitative and qualitative analysis of Participant Experience Survey

Secondary Outcome Measures
NameTimeMethod
Witnessed change in FMD between treated and untreated subjects6 months

Flow Mediated Dilatation

Witnessed change in T lymphocyte subset frequency between treated and untreated subjects6 months

CD4+CD28null T lymphocytes and Regulatory T cells as determined by flow cytometry of whole blood

Witnessed change in CIMT between treated and untreated subjects6 months

Carotid Intima Media Thickness

Trial Locations

Locations (1)

Debasish Banerjee

🇬🇧

London, Tooting, United Kingdom

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