Mono-centred, randomised, placebo-controlled, double-blind parallel-arm study on the effect of Conjugated Linoleic Acid (CLA) on endothelial function and (postprandial) metabolic parameters in overweight men
ISRCTN | ISRCTN30870177 |
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DOI | https://doi.org/10.1186/ISRCTN30870177 |
Secondary identifying numbers | N/A |
- Submission date
- 03/09/2008
- Registration date
- 17/10/2008
- Last edited
- 03/01/2012
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Plain English summary of protocol
Not provided at time of registration
Contact information
Prof Juergen Schrezenmeir
Scientific
Scientific
Max Rubner-Institute
Federal Research Centre for Nutrition and Food
Hermann-Weigmann-Str. 1
Kiel
24103
Germany
Phone | +49 (0)431 609 2220 |
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juergen.schrezenmeir@mri.bund.de |
Study information
Study design | Single centre, randomised double-blind placebo-controlled intervention study |
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Primary study design | Interventional |
Secondary study design | Randomised controlled trial |
Study setting(s) | Not specified |
Study type | Treatment |
Scientific title | |
Study acronym | CLA1 |
Study objectives | 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(s) | 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) |
Health condition(s) or problem(s) studied | 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 |
Pharmaceutical study type(s) | |
Phase | Not Specified |
Drug / device / biological / vaccine name(s) | 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 study start date | 18/04/2006 |
Completion date | 02/08/2006 |
Eligibility
Participant type(s) | Patient |
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Age group | Adult |
Sex | Male |
Target number of participants | 88 |
Key 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 |
Key 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 |
Date of first enrolment | 18/04/2006 |
Date of final enrolment | 02/08/2006 |
Locations
Countries of recruitment
- Germany
Study participating centre
Max Rubner-Institute
Kiel
24103
Germany
24103
Germany
Sponsor information
Max Rubner Institute (Germany)
Research organisation
Research organisation
c/o Prof. Juergen Schrezenmeir
Federal Research Centre for Nutrition and Food
Haid-und-Neu-Str. 9
Karlsruhe
76131
Germany
Phone | +49 (0)721 6625 400 |
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pbe.kiel@mri.bund.de | |
Website | http://www.bfel.de |
https://ror.org/045gmmg53 |
Funders
Funder type
Government
Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung [BMBF]) (Germany)
Government organisation / National government
Government organisation / National government
- Alternative name(s)
- Federal Ministry of Education and Research, BMBF
- Location
- Germany
Federal Ministry of Food, Agriculture and Consumer Protection (Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz) (Germany)
No information available
Cognis GmbH (Germany)
No information available
Results and Publications
Intention to publish date | |
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Individual participant data (IPD) Intention to share | No |
IPD sharing plan summary | Not provided at time of registration |
Publication and dissemination plan | Not provided at time of registration |
IPD sharing plan |
Study outputs
Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
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Results article | results | 01/02/2011 | Yes | No |