Contact information
Type
Scientific
Primary contact
Prof Juergen Schrezenmeir
ORCID ID
Contact details
Max Rubner-Institute
Federal Research Centre for Nutrition and Food
Hermann-Weigmann-Str. 1
Kiel
24103
Germany
+49 (0)431 609 2220
juergen.schrezenmeir@mri.bund.de
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
Acronym
CLA1
Study hypothesis
Conjugated linoleic acid (CLA) may beneficially affect lipid and glucose metabolism, inflammatory responses and body weight. These aspects are of relevance for subjects afflicted with or prone to develop a so-called metabolic syndrome, which is characterised by an insulin resistance, dyslipidaemia, essential hypertension and adiposity of the central type and frequently leads to early manifestation of type 2 diabetes mellitus, increased vascular risk and risk of atherosclerosis. This study examines the influence of dietary conjugated linoleic acid (CLA) (commercially available 50:50 mixture of isomers cis9,trans11-CLA and trans10,cis12-CLA) on endothelial function and below mentioned fasting and postprandial metabolic parameters in comparison to safflower oil. For explorative purposes two more groups are given native olive oil or heated (thermally oxidised) safflower oil. Tocopherol concentration of the supplements is adjusted to that of safflower oil. Further parameters to judge pro-atherogenic processes are soluble adhesion molecules (intercellular adhesion molecule [ICAM], vascular cell adhesion molecule [VCAM], E-Selectin) which promote inflammatory processes by initiating the adherence of leukocytes and monocytes to the endothelium of blood vessels.
Ethics approval
Ethics approval received from the Ethics Committee of the Medical Faculty of the Christian-Albrechts-University of Kiel (Germany) on the 13th April 2006 (ref: A 106/06)
Study design
Single centre, randomised double-blind placebo-controlled intervention study
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Not specified
Trial type
Treatment
Patient information sheet
Condition
Cardiovascular disease
Intervention
Group 1: CLA 50:50 isomer mixture (cis9,trans11-CLA: trans10,cis12-CLA)
Group 2: safflower oil
Group 3: native olive oil
Group 4: safflower oil - thermally oxidised
Supplements given two times a day during breakfast (or lunch) and dinner, four capsules each, making a total dose per day of eight capsules (= 4.5 g). Total duration of treatment was 4 weeks (28 + 2 days), for all four treatments.
Follow up:
Start of the follow up period, i.e. start of the intervention for the first study subjects was 24/04/2006. End of the trial follow-up period was 02/08/2006.
Intervention type
Drug
Phase
Not Specified
Drug names
Conjugated linoleic acid (CLA), safflower oil, native olive oil
Primary outcome measure
Changes in endothelial function: PAT-Index after 28(± 2) days supplementation.
Secondary outcome measures
1. Body mass index (BMI)
2. Waist circumference (WC)
3. Waist to hip ratio (WHR)
4. Blood pressure, pulse
Changes in:
5. Fasting and postprandial triglycerides (AUC)
6. Fasting and postprandial insulin (AUC)
7. Fasting and postprandial glucose (AUC)
8. Homeostasis model assessment of insulin resistance (HOMA-IR) (insulin-glucose-product)
9. HOMA-b-cell-function
10. Lipids, namely total, low density lipoprotein (LDL-) and high density lipoprotein (HDL-) cholesterol
11. Oxidative modification of lipids and oxidative stress, namely: oxidised LDL, isoprostanes
13. Inflammatory parameters, namely: C-reactive protein (CRP), soluble vascular cell adhesion molecule (sVCAM), soluble intercellular adhesion molecule (sICAM), soluble E-selectin, interleukin-6 (IL-6), tumour necrosis factor alpha (TNF alpha), monocyte chemoattractant protein-1 (MCP-1)
14. Other regulators/hormones: adiponectin, leptin, ghrelin, glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), vascular endothelial growth factor (VEGF)
All secondary parameters were determined both at start of the intervention (day 0) and end of the study, i.e. after 4 weeks. Treatment-induced changes were calculated and compared between intervention groups.
Overall trial start date
18/04/2006
Overall trial end date
02/08/2006
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Healthy male volunteers
2. Aged 45 - 68 years
3. Body mass index (BMI) 25 - 29 kg/m^2
4. Member of the Metabolic Intervention Cohort Kiel (MICK)
5. Written informed consent
Participant type
Patient
Age group
Adult
Gender
Male
Target number of participants
88
Participant exclusion criteria
1. Participation in a clinical study with a medicament or a medicinal product within the last 30 days or simultaneous participation in another clinical examination
2. Inability to understand and to comply with the study protocol
3. Known metabolic or gastro-intestinal diseases, which affect the absorption, metabolism or excretion of food or food components
4. Condition after surgery of the gastro-intestinal tract, which affects gastro-intestinal motility
5. Haemoglobin less than 12 g/dL
6. Latex allergy
7. Diabetes (fasting glucose levels greater than 125 mg/dl after repeated determination)
8. Surgery within the last 3 months, which still affects the current state of health
9. Intake of nitrate and/or calcium antagonists, which affect the blood pressure
10. Deformation of finger tips, which inhibits correct recording of EndoPAT (measures a Peripheral Arterial Tone [PAT™] signal for assessment of endothelial dysfunction)
11. Illness of thyroid gland, which has metabolic and/or cardiovascular effect
12. Known hepatitis B, hepatitis C, human immunodeficiency virus (HIV) infection or chronic liver disease
13. Kidney malfunction
14. Psychiatric disorders, epilepsy, risk of suicide
15. Drug or alcohol abuse
16. Intake of drugs affecting the absorption, metabolism or excretion of food components or the gastro-intestinal motility
17. Intake of hormone preparations, particularly cortisone
18. Eating disorders, anorexia, bulimia, unusual outsider dietary habits
19. Legal incapacity
20. Others depending on the judgement of the study physician
Recruitment start date
18/04/2006
Recruitment end date
02/08/2006
Locations
Countries of recruitment
Germany
Trial participating centre
Max Rubner-Institute
Kiel
24103
Germany
Sponsor information
Organisation
Max Rubner Institute (Germany)
Sponsor details
c/o Prof. Juergen Schrezenmeir
Federal Research Centre for Nutrition and Food
Haid-und-Neu-Str. 9
Karlsruhe
76131
Germany
+49 (0)721 6625 400
pbe.kiel@mri.bund.de
Sponsor type
Research organisation
Website
Funders
Funder type
Government
Funder name
Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung [BMBF]) (Germany)
Alternative name(s)
Federal Ministry of Education and Research, BMBF
Funding Body Type
government organisation
Funding Body Subtype
National government
Location
Germany
Funder name
Federal Ministry of Food, Agriculture and Consumer Protection (Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz) (Germany)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Funder name
Cognis GmbH (Germany)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
1. 2011 results in http://www.ncbi.nlm.nih.gov/pubmed/21697535
Publication citations
-
Results
Pfeuffer M, Fielitz K, Laue C, Winkler P, Rubin D, Helwig U, Giller K, Kammann J, Schwedhelm E, Böger RH, Bub A, Bell D, Schrezenmeir J, CLA does not impair endothelial function and decreases body weight as compared with safflower oil in overweight and obese male subjects., J Am Coll Nutr, 2011, 30, 1, 19-28.