Effect of Betaine, Serine and Folic Acid on Vascular Function in Healthy Volunteers

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00126347
Recruitment Status : Completed
First Posted : August 3, 2005
Last Update Posted : August 18, 2005
Information provided by:
Wageningen Centre for Food Sciences

Brief Summary:
The purpose of this study is to determine whether reducing the increase in plasma homocysteine concentrations following an oral methionine load affects vascular function in healthy volunteers, irrespective of the homocysteine-lowering agent.

Condition or disease Intervention/treatment Phase
Healthy Cardiovascular Diseases Procedure: supplementation with betaine, serine, and folic acid Not Applicable

Detailed Description:

A high plasma homocysteine is a potential risk factor for cardiovascular disease and death. However, it remains uncertain whether homocysteine per se, low status of folate, or other factors related to methionine metabolism are involved in the pathogenesis of cardiovascular disease. Previous studies have shown that a high concentration of homocysteine in blood is related to an impaired vascular function in the arteries, an indicator of cardiovascular disease risk. Virtually all intervention trials used folic acid as a homocysteine-lowering agent, which may however affect vascular function through mechanisms not related to homocysteine. The researchers investigated whether reduction in homocysteine concentrations following a methionine load, via supplementation with serine, betaine or folic acid improves vascular function in healthy volunteers, in order to distinguish between effects of folic acid and of homocysteine-lowering per se.

Comparison: The effects of supplementation with serine, folic acid and betaine (all together with an oral methionine load) were compared to the effects of a placebo (together with a methionine load) on plasma homocysteine concentrations and on vascular function following methionine loading in healthy volunteers.

Study Type : Interventional  (Clinical Trial)
Enrollment : 40 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Prevention
Official Title: Effect of Lowering of Plasma Homocysteine Concentrations After an Oral Methionine Load on Vascular Function in Healthy Volunteers
Study Start Date : August 2002
Study Completion Date : July 2003

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Primary Outcome Measures :
  1. concentrations of plasma homocysteine before and following an oral methionine load
  2. vascular function, measured as flow mediated vasodilation before and following an oral methionine load

Secondary Outcome Measures :
  1. B-vitamins
  2. blood pressure

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Apparently healthy
  • Women postmenopausal: two or more years after last menstruation. If the uterus was surgically removed, the women must be 55 years or older
  • Normal blood values for: hematology, total homocysteine, lipids, vitamin B6, vitamin B12, folic acid, liver enzymes, creatinine
  • Absence of protein and glucose in urine sample
  • Body mass index (BMI) between 18 and 30 kg/m2
  • Good ultrasound visibility of the brachial artery, judged by a sonographer.
  • Willing not to use supplements containing B-vitamins, antioxidant vitamins (A, beta-carotene, C and E) or n-3 fatty acids/fish oil supplements from screening day (>2 months before start of the study) until end of study
  • Willing not to be blood or plasmapherese donor from 4 weeks before the screening day, and 4 weeks before the start of the study until the end of study

Exclusion Criteria:

  • Any chronic or acute disease (e.g. diabetes, renal disease, inflammation)
  • Current, or history of cardiovascular disease
  • Hypertension
  • Medical history or surgical events know to interfere with the study
  • Fasting plasma total homocysteine > 26 micromol/L
  • Alcohol consumption: women >21 consumptions/week; men >28 consumptions/week
  • Weight loss or gain > 2 kg in the month prior to screening
  • Any special diet (prescribed, slimming, macrobiotic or total vegetarian. Sole exclusion of meat and fish from a otherwise ‘normal’ western diet is allowed).
  • Lactose intolerance
  • Use of supplements containing B-vitamins more than once weekly in the period from 3 months before the screening day
  • Participation in any other trial up to 3 months before this study
  • Use of medication known to interfere with the study outcome.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00126347

Wageningen Centre for Food Sciences
Wageningen, Netherlands
Sponsors and Collaborators
Wageningen Centre for Food Sciences
Study Chair: Petra Verhoef, PhD Wageningen Centre for Food Sciences

Additional Information: Identifier: NCT00126347     History of Changes
Other Study ID Numbers: P02.0470L
First Posted: August 3, 2005    Key Record Dates
Last Update Posted: August 18, 2005
Last Verified: August 2005

Keywords provided by Wageningen Centre for Food Sciences:
folic acid
methionine load
cardiovascular health
vascular function

Additional relevant MeSH terms:
Cardiovascular Diseases
Folic Acid
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs
Gastrointestinal Agents
Lipotropic Agents
Hypolipidemic Agents
Molecular Mechanisms of Pharmacological Action
Lipid Regulating Agents