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ISRCTN
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ISRCTN45296887
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ClinicalTrials.gov identifier
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Public title
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Plasma homocysteine response to folic acid intervention
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Scientific title
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A dose finding trial in ischaemic heart disease patients and healthy controls to determine whether chronic exposure to low-dose folic acid can lower homocysteine
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Acronym
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N/A
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Serial number at source
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N/A
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Study hypothesis
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Low dose folic acid (0.2 mg/d) administered chronically will significantly lower plasma homocysteine in ischaemic heart disease (IHD) patients and healthy age-sex matched controls. Previous studies may have overestimated the folic acid dose required to lower homocysteine because of too-short an intervention period to observe the full extent of the response to low folic acid doses and concluded that much higher doses were required for maximal homocysteine-lowering.
If the hypothesis is confirmed the findings will have important implications for governments worldwide currently considering food fortification with folic acid, which although primarily aimed at reducing neural tube defects (NTDs), is expected to have important benefits in terms of the primary and secondary prevention of cardiovascular disease (CVD) via a homocysteine-lowering effect.
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Lay summary
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Ethics approval
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The study was approved by the University of Ulster Ethics committee in March 2000 (ref: 01/17).
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Study design
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Double-blinded, randomised, placebo controlled dose finding trial with folic acid
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Countries of recruitment
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United Kingdom
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Disease/condition/study domain
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Ischaemic heart disease
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Participants - inclusion criteria
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1. Male and female, any age
2. IHD Patients:
2.1. Proven myocardial infarction more than three months previously
2.2. IHD on coronary angiography
2.3. A clinical diagnosis of angina confirmed by electrocardiogram (ECG)
3. Control subjects: healthy subjects age- and sex-matched with the IHD group from the local community
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Participants - exclusion criteria
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1. IHD patients:
1.1. History of diabetes
1.2. Hepatic or renal disease
1.3. Haematological disorders
1.4. Use of B-vitamin supplements or use of medication known to interfere with folate metabolism
2. Healthy controls in addition had no history of CVD
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Anticipated start date
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31/03/2001
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Anticipated end date
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31/12/2004
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Status of trial
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Completed |
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Patient information material
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Not available in web format, please use the contact details below to request a patient information sheet
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Target number of participants
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n = 200 (100 patients, 100 controls)
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Interventions
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In both IHD and healthy control groups, participants were stratified into tertiles of homocysteine concentration (from the screening blood sample). Subjects in each stratum were then randomised to receive placebo, 0.2, 0.4 or 0.8 mg/d folic acid for a total intervention period of 26 weeks. To maximise compliance, vitamins were distributed every three weeks to the participants’ homes in seven-day pillboxes. The pillboxes were then collected and any unused pills recorded in order to monitor compliance.
Total intervention period of 26 weeks for all treatment arms.
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Primary outcome measure(s)
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Plasma homocysteine, measured at baseline, 6 weeks and 12 weeks in a subset, and at 26 weeks.
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Secondary outcome measure(s)
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1. Serum folate, measured at baseline and at 26 weeks
2. Erythrocyte glutathione reductase activity coefficient (EGRac): an indicator of riboflavin status), measured at baseline
2. Plasma pyridoxal phosphate: an indicator of vitamin B6 status, measured at baseline
3. Serum vitamin B12, measured at baseline
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Sources of funding
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Northern Ireland Chest Heart and Stroke Association (UK)
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Trial website
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Publications
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1. 2011 results in http://www.ncbi.nlm.nih.gov/pubmed/20980493
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Contact name
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Dr
Mary
Ward
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Address
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Northern Ireland Centre for Food and Health
School of Biomedical Sciences
University of Ulster
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City/town
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Coleraine
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Zip/Postcode
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BT521SA
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Country
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United Kingdom
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Tel
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+44 (0)28 7032 3076
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Email
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mw.ward@ulster.ac.uk
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Sponsor
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University of Ulster (UK)
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Address
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c/o Mary Ward
School of Biomedical Sciences
Cromore Road
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City/town
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Coleraine
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Zip/Postcode
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BT52 1SA
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Country
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United Kingdom
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Tel
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+44 (0)28 7032 3076
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Email
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mw.ward@ulster.ac.uk
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Sponsor website:
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http://www.ulster.ac.uk/
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Date applied
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29/01/2008
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Last edited
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02/02/2011
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Date ISRCTN assigned
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05/03/2008
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