Trial to Assess the Effects of Different Trans-fatty Acids on Endothelial Function in Humans

This study has been terminated.
(Recruitment problems)
Sponsor:
Collaborators:
Agroscope Liebefeld-Posieux Research Station ALP
University of Bern
Schweizerische Herzstiftung
Bundesamt für Landwirtschaft
Emmi Schweiz AG
Information provided by:
University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier:
NCT00933322
First received: July 2, 2009
Last updated: July 11, 2013
Last verified: July 2013
  Purpose

The aim of the study is to compare a diet rich in trans fatty acids (TFA) from ruminant sources with a diet rich in TFA from hydrogenated vegetable oils (PHVO) in regard to their effects on cardiovascular risk markers (endothelial function, blood lipids, inflammation and coagulation parameters in the blood).

After a two week run-in period (diet without TFA) volunteers are randomized into three groups with different diets: diet rich in TFA from ruminant sources, diet rich in TFA from PHVO and diet without TFA. The intervention period lasts four weeks.

A nutritionist introduces the basic issues of the study diets. All volunteers supply themselves according to the recommendations of the Swiss food pyramid. Fat free food can be chosen individually in the context of defined guidelines. The amount and source of the fat in the diet are strictly defined. During the whole study, volunteers meet the nutritionist every 2 weeks, and in the weeks between, the volunteers are contacted by phone.

The volunteers will continue their normal daily life and physical activities. At the beginning of the run-in period and at the beginning and the end of the intervention period the endothelial function of the brachial artery will be assessed using flow-mediated dilation (FMD)/nitro-mediated dilation (NMD) methods and blood samples will be collected to analyze blood lipids, inflammation and coagulation parameters in the blood.

Hypothesis:

  1. Diet enriched with ruminant TFA has not the same negative effect on cardiovascular risk markers as diet enriched with the same amount of industrial TFA compared with a diet without TFA.
  2. Diet enriched with ruminant TFA has not a more negative effect on cardiovascular risk markers as diet without TFA.

Condition Intervention
Healthy
Dietary Supplement: diet enriched with industrial trans fatty acids
Dietary Supplement: diet enriched with ruminant trans fatty acids
Dietary Supplement: diet without any trans fatty acids

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Randomized-controlled Trial to Assess the Effects of Different Trans-fatty Acids on Endothelial Function in Humans

Resource links provided by NLM:


Further study details as provided by University Hospital Inselspital, Berne:

Primary Outcome Measures:
  • endothelial function using flow-mediated dilation [ Time Frame: 3 time points over 6 weeks (after 0, 2, 6 weeks) ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • inflammation parameters in blood samples [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  • coagulation parameters in blood samples [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  • blood lipids in blood samples [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  • adhesion molecules in blood samples [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  • insulin resistance via blood samples [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]

Enrollment: 142
Study Start Date: July 2009
Study Completion Date: June 2013
Primary Completion Date: June 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: ruminant TFA
In addition to the basic diet, volunteers enrich their diet with an individually calculated amount of butter containing ruminant TFA and with 15-20g rape oil for balancing the essential fatty acids.
Dietary Supplement: diet enriched with ruminant trans fatty acids
After run-in phase of 2 weeks with margarine without TFA, 4 weeks with butter enriched with ruminant trans fatty acids following. TFA-percentage of total energy consumption is 2% or 6% of total fat energy consumption.
Active Comparator: industrial TFA
In addition to the basic diet, volunteers enrich their diet with an individually calculated amount of butter containing TFA from PHVO and with 15-20g rape oil for balancing the essential fatty acids.
Dietary Supplement: diet enriched with industrial trans fatty acids
After run-in phase of 2 weeks with margarine without TFA, 4 weeks with margarine enriched with industrial trans fatty acids following. TFA-percentage of total energy consumption is 2% or 6% of total fat energy consumption.
Placebo Comparator: without TFA
In addition to the basic diet, volunteers enrich their diet with an individually calculated amount of butter without TFA and with 15-20g rape oil for balancing the essential fatty acids.
Dietary Supplement: diet without any trans fatty acids
6 weeks with margarine without any trans fatty acids.

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   45 Years to 69 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • age 45-69
  • body mass index 20-30 kg/m2
  • willingness to hold physical activity constant over study duration
  • written informed consent

Exclusion Criteria

  • smoking
  • hypertension (> 140/90 mm Hg)
  • hypotension (men < 115 mm Hg; women < 105 mm Hg)
  • obesity (BMI =/> 30 kg/m2)
  • vegan
  • infections in the last 6 weeks
  • allergy for food (e.g., milk)
  • pregnancy
  • diabetes (elevated fasting blood glucose level)
  • clinical known coronary diseases
  • acute and/or chronical medication (incl. contraceptive)
  • abnormal kidney function
  • abnormal liver function
  • known cardiac arrhythmia (e.g., atrial fibrillation)
  • blood parameters (ALAT, Creatinin, Hb, potassium, CRP) in range
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00933322

Locations
Switzerland
Cardiovascular Prevention and Rehabilitation, Bern University Hospital
Bern, Switzerland, 3010
Sponsors and Collaborators
University Hospital Inselspital, Berne
Agroscope Liebefeld-Posieux Research Station ALP
University of Bern
Schweizerische Herzstiftung
Bundesamt für Landwirtschaft
Emmi Schweiz AG
Investigators
Study Director: Hugo Saner, Prof. Dr. med Cardiovascular Prevention and Rehabilitation, University Hospital Bern, Switzerland
Study Director: Alexandra Schmid, Dipl. oec. troph. Agroscope Liebefeld-Posieux Research Station ALP, Posieux, Switzerland
Principal Investigator: Thomas Radtke, MSc Cardiovascular Prevention and Rehabilitation, University Hospital Bern, Switzerland
  More Information

Publications:

Responsible Party: Hugo Saner/ Prof. Dr. med, Bern University Hospital
ClinicalTrials.gov Identifier: NCT00933322     History of Changes
Other Study ID Numbers: KEK 124/09
Study First Received: July 2, 2009
Last Updated: July 11, 2013
Health Authority: Switzerland: Ethikkommission

Keywords provided by University Hospital Inselspital, Berne:
ruminant
industrial
endothelial function
flow-mediated dilation
blood lipids
nutrition
trans fatty acids
coronary disease
endothelial function of the brachial artery
inflammation
insulin resistancy
coagulation

ClinicalTrials.gov processed this record on September 16, 2014